Category: Vitamins

Introduction

The common cold, also known as nasopharyngitis or non-specific upper respiratory infection (URI), is a viral infection and one of the world’s most common respiratory health illnesses, other causes include coronavirus, parainfluenza, and influenza (Eccles et al., 2015; Hemilä, 2017). It is associated with acute morbidity, acute ear infections, acute sinusitis, asthma, and other secondary infections (Heimer, Hart, Martin, & Rubio-Wallace, 2009). In the United States alone, more than one billion cases of the common cold are diagnosed annually (Heimer et al., 2009). Loosely translated, each person experiences about two to six colds every year. Therefore, it is one of the main reasons why people seek health care services and possibly a key driver for the high number of clinic visits reported annually (Heimer et al., 2009).

The common cold has several implications for the social, economic, and political development of many communities. It is a nuisance to daily life and is a recurrent and common cause of morbidity (Braun et al., 2000). Additionally, it has huge financial costs to societies because it has several direct and indirect costs related to health care service provision (Fendrick, Monto, Nightengale, & Sarnes, 2003).

The treatment of the common cold is largely limited to interventions that focus on symptom relief. The most common methods used to manage the condition are based on the administration of pharmacological interventions such as pseudoephedrine and guaifenesin as well as popular marketed herbal supplement vitamin C, including Airborne, and Halls Defense Vitamin C Drops. (Heimer et al., 2009). However, the efficacy of these techniques in the management of common cold symptoms is inconclusive. Particularly, there is no proper understanding regarding the use of nutritional supplements, such as vitamin C, in the management of common cold symptoms. At present, the literature appears to be lacking information about the use of vitamin C for treatment or prophylaxis of the common cold thus leaving practitioners to face the dilemma of how to advise patients regarding its use. The purpose of this paper is to understand the effects of vitamin C supplements have on the frequency and incidence of the common cold. The findings may potentially lead to the development of evidence-based suggestions to manage the common cold.

Search Process for the Articles

A literature search, for primary research reports, was done using search engines EBSCO, CINAHL, The National Library of Medicine (PubMed), and google scholar in June 2018 regarding the efficacy of vitamin C for the prevention and treatment of the common cold. Key terms and phrases were vitamin C AND common cold, ascorbic acid AND common cold, common cold, complimentary AND alternative medicine, and upper respiratory infection. The search period was 1990 – 2018. The review was limited to articles that contained original research, systematic reviews, or meta-analysis. Exclusion criteria were articles in languages other than English, articles that were unpublished, and publication dates of 1990 – 2018. Inclusion criteria were prevention, education, and primary care. From this process, 54 original articles were obtained and 46 were removed based on the inclusion and exclusion criteria.

Synthesis of Findings

Reduction in Common Cold Symptoms

Most of the evidence sampled in this review pointed to a reduction in common cold frequencies, severity, and duration after the administration of vitamin C supplements on selected groups of patients. Ran et al. (2018) authored one of the studies reviewed and reported a reduction in the duration of the common cold because of the administration of vitamin C. The authors also established a shortened indoor time for patients who suffered from the common cold because of the intake of vitamin C supplements (Ran et al., 2018). Overall, the study demonstrated that extra doses of vitamin C were important to patients who took daily doses of the same supplement. These findings mirror those of Hemilä (1999), which also show that vitamin C helps to reduce the duration and severity of common cold infections. However, unlike Ran et al. (2018), Hemilä (1999) opines that there are variations in benefits between children and adults.

Notably, the author argues that children, as opposed to adults, enjoyed the greatest relief of common cold symptoms through vitamin C supplementation (Hemilä, 1999). He also demonstrated that variations in dosages also affected the magnitude of the symptoms. For example, a dosage of more than 2g/day was found to be more effective in alleviating symptoms of common cold compared to one of 1g/day (Hemilä, 1999). The same report acknowledged variations in the alleviation of common cold symptoms, but still supported the view that the administration of vitamin C supplements decreases the duration of episodes and severity of its symptoms (Hemilä, 1999). Unlike the study by Ran et al. (2018), Hemilä (1999) cited the extent of alleviation of common cold symptoms by saying that it reduces the incidence of the condition by up to 23%. Other researchers sampled in this review did not provide an estimate of the same.

The reduction in common cold symptoms through vitamin C supplementation was also reported by Van Straten and Josling (2002) who used 168 respondents to study the effects of vitamin C supplementation on the effects of the common cold. The study demonstrated that respondents who took at least 2g/day of vitamin C supplements were less likely to get a cold (Van Straten & Josling, 2002). Even if they did, they recovered faster than those who did not take the same supplements (Van Straten & Josling, 2002). Based on this finding, the researchers proposed that vitamin C should be used as an agent for reducing the frequency and duration of the common cold (Van Straten & Josling, 2002). This recommendation was made against the backdrop of a high level of satisfaction among the respondents about the efficacy of vitamin C in minimizing the occurrence and severity of common cold during winter (Van Straten & Josling, 2002).

The study by Johnston, Barkyoumb, and Schumacher (2014) also supports the positive effects of vitamin C on the reduction of common cold symptoms. It links the condition with a reduction in physical activity and demonstrates that vitamin C intake helps to improve physical activity levels (Johnston et al., 2014). Stated differently, the study generally pointed to the existence of positive and measurable health advantages associated with vitamin C supplementation (Johnston et al. 2014). The greatest effects were reported among male populations with adequate-to-low vitamin C levels (Johnston et al. 2014). Unlike other studies highlighted in this review, the one by Johnston et al. (2014) was gender-specific in its analysis of the effects of the common cold.

A different study by Hemilä (2013) also highlighted the positive effects of vitamin C on the reduction of common cold symptoms because it suggested that the supplements helped to reduce bronchial hypersensitivity. Unlike other studies highlighted in this review, the investigation by Hemilä (2013) evaluated the impact of vitamin C on common cold-induced asthma and used a small sample size of 79 people. This group of respondents was recruited for the study to participate in three clinical trials. Similarly, unlike the findings of Johnston et al. (2014), those of Hemilä (2013) only applied to men. Although three clinical trials that underscored the review differed in terms of methodological approaches, they all affirmed health benefits in the administration of vitamin C supplements to patients who suffered from the common cold (Johnston et al., 2014). Given the positive relationship between vitamin C supplementation and the alleviation of common cold symptoms, the researchers also emphasized the need to test the administration of vitamin C on an individual basis (Hemilä, 2013). At the same time, they recommended further exploration of the effects of vitamin C on common-cold-induced asthma (Hemilä, 2013).

Limited Effects of Vitamin C

Although the above-mentioned studies report a generally positive effect of vitamin C use on the reduction or minimization of common cold symptoms, some researchers do not share the same confidence. For example, the study by Sasazuki et al. (2006) found no significant reduction in the severity and duration of common cold symptoms through the administration of vitamin C. They reported these findings after investigating how a group of 244 respondents who suffered from atrophic gastritis responded to a randomized controlled trial that provided them with 50 or 500mg of vitamin C supplements (Sasazuki et al., 2006). Although these findings slightly differ with those of Ran et al. (2018), Hemilä (1999), and Van Straten and Josling (2002), they affirm a reduction in the frequency of common cold symptoms based on vitamin C administration. Therefore, unlike other studies highlighted in this review, which explicitly support the efficacies of vitamin C in the reduction of common cold symptoms, this study is implicit when making such claims.

Audera, Patulny, Sander, and Douglas (2001) adopted the same cautious approach in a study that sought to find out the effects of large doses of vitamin C on common cold symptoms. Using a double-blind randomized controlled trial, they reported that doses of vitamin C in excess of 1g/day were insufficient in reducing the duration and frequency of common cold symptoms (Audera et al., 2001). Comparatively, a vitamin C dose, which was less than the recommended intake had a stronger effect in reducing the effects of the common cold (Audera et al., 2001). These findings were developed after testing for the impact of the supplements on 400 adult volunteers who were students and staff of the Australian National University (Audera et al., 2001).

Broadly, the studies highlighted above show that vitamin C is associated with a decline in the frequency and severity of common cold symptoms. Differences in methodologies and research approaches could largely account for variations in the degree of symptomatic relief reported in the papers. However, they support the view that vitamin C leads to a decline in common cold severity and frequency. A summary of the review appears in the appendix section.

Implications for Clinical Practice

All of the articles reviewed above were relevant to the EBP question, which sought to establish whether people who consumed vitamin C supplements experienced fewer symptoms of the common cold. Based on this EBP question, the findings of the study are instrumental to the nursing practice because they help to expand the volume of literature explaining the benefits of vitamin C on the common cold and other ailments. Some of the studies analyzed were also instrumental in understanding the limitations of vitamin C intake. For example, the one by Audera et al. (2001) was instrumental in this regard. Relative to this view, the findings of the article are also integral to the nursing practice because they help in explaining the properties of vitamin C that affect the human immune system (Hemilä, 1994). Collectively, the study’s findings are instrumental in enhancing patient satisfaction, which is deemed to be at the heart of the nursing practice. They also give useful insights regarding how to manage the common cold, which is a common respiratory illness. Therefore, they are useful to the global nursing field.

Based on the above-mentioned facts, future studies should try to determine the extent that vitamin C improves the human immune system. At the same time, there should be a reexamination of the use of large quantities of vitamin C to manage common cold symptoms. Since some of the studies sampled also highlighted varying levels of effectiveness in the alleviation of common cold symptoms (using vitamin C supplementation), future research should explain why there are variations in vitamin C effectiveness when treating the common cold. As proposed by Hemilä (1999), the use of further therapeutic trials could be instrumental in explaining differences in vitamin C effectiveness when treating the common cold.

The findings that emerge from this literature review also have a significant impact on my role as a nursing practitioner because I have experienced (first-hand) the effects of the common cold and seen how it not only affects the quality of my colleagues’ work, but also those of patients who come to the healthcare facility to seek relief. However, my knowledge of common cold management is limited to the administration of generic medications. The findings of this paper provide a deeper insight into the management of the condition because they explain the dietary and nutritional role of vitamin C in the management of the same. This knowledge is not only critical to improving my understanding of the relationship between vitamin C intake but also integral in my comprehension of its benefits because I have only heard of its extensive advantages without a proper understanding of the evidence that supports or negates what I know. Therefore, the use of evidence-based research studies to demystify some of these issues is beneficial to me, not only from a professional point of view but also from a personal point of view.

The only issue of contention I have with the findings that have emerged from this review is their failure to explain the extent of vitamin C efficacy in the alleviation of common cold symptoms because most of them have only affirmed a positive relationship between both variables. Understandably, the variations in efficacy levels could be narrowed down to the type of sample chosen. However, there needs to be a clearer explanation of the types of populations or demographics that could benefit the most from vitamin C intake and why this is so because, in my own nursing experience, I have found that certain population groups tend to respond better to specific treatments, while others do not. This view informs the need for more focused clinical trials to explicitly state and describe variations in vitamin C treatments across different groups of people.

Gaps in Literature

Most of the literature sampled in this study established a relationship between the dependent and independent variables, which were vitamin C intake and common cold symptoms. One gap in the literature that emerges from this analysis is the failure of the study to quantify the extent that these two variables are related. Furthermore, the establishment of a correlation between the two variables does not necessarily mean there is causation. This gap in the literature exists because some of the studies revealed varying levels of common cold symptoms, relative to the consumption of vitamin C supplements. Therefore, there is no quantification of the extent of vitamin C use in the alleviation of common cold symptoms. Another gap in the literature that partly explains this problem is the failure of the research studies to categorize the effects of vitamin C use according to different age groups. This observation stems from the review of selected studies, which showed varying levels of efficacy of vitamin C intake based on population dynamics. For example, the study by Hemilä (1999) showed varying levels of efficacy of vitamin C intake in the alleviation of common cold symptoms among adults and children.

The use of small sample size is also another gap in literature because some of the studies sampled relied on a small sample, which could not be generalized across a large population. For example, the study by Audera et al. (2001) only included 400 participants, while that of Hemilä (2013) used only 79 people. Comparatively the sample size used by Sasazuki et al. (2006) was 439 people. These sample sizes are small relative to the generalizability of the findings across large populations. For example, most of the studies mentioned above do not highlight racial, or age disparities that would make people understand the nature of their sample. Indeed, it would be difficult to understand how a study that only relies on about 400 people could be justifiably used to generalize the effects of vitamin C on common cold symptoms for all adults. In this regard, future research should strive to accommodate a larger sample size to improve the ability to generalize their findings across a larger sample size.

Summary

From the onset of this paper, it was established that the EBP question for this review sought to find out the impact of vitamin C intake on the alleviation of common cold symptoms. The main research question stated, “Do patients who take vitamin C supplements develop common cold more or less often than patients who do not take supplements?” The findings of all the eight articles sampled aligned with the research question. Notably, they affirmed a positive relationship between vitamin C intake and the minimization of common cold symptoms. Significant gaps that emerged from a review of the articles centered on the small sample size used in most of the studies to support their findings and the failure of the articles to show the extent of correlation between the dependent and independent variables. These areas of focus largely explain the direction that future research should follow.

References

Audera, C., Patulny, R., Sander, B., & Douglas, R. (2001). Mega-dose vitamin C in treatment of the common cold: A randomized controlled trial. The Medical journal of Australia, 175, 359-362.

Braun, B.L., Fowles, J.B., Solberg, L., Kind, E., Healey, M., & Anderson, R. (2000). Patient beliefs about the characteristic, causes, and care of the common cold. Journal of Family Practice, 49(2), 153-156.

Eccles, R., Winther, B., Johnston, S.L., Robinson, P., Trampisch, M., & Koelsch, S. (2015). Efficacy and safety of iota-carrageenan nasal spray versus placebo in early treatment of the common cold in adults: The ICICC trial. Respiratory Research, 16, 121.

Fendrick, A.M., Monto, A.S., Nightengale, B., & Sarnes, M. (2003). The economic burden of Non-influenza-related viral respiratory tract infection in the United States. Archives of Internal Medicine, 163(4), 487-494.

Heimer, K.A., Hart, A.M., Martin, L.G., & Rubio-Wallace, S. (2009). Examine evidence for the use of vitamin C in the prophylaxis and treatment of common cold. Journal of the American Academy of Nurse Practitioners, 21(5), 295-300.

Hemilä, H. (1994). Does vitamin C alleviate the symptoms of the common cold? A review of current evidence. Scandinavian Journal of Infectious Diseases, 26, 1-6.

Hemilä, H. (1999). Vitamin C supplementation and common cold symptoms: Factors affecting the magnitude of the benefit. Medical Hypotheses, 52(2), 171-178.

Hemilä, H. (2013). Vitamin C and common cold-induced asthma: A systematic review and statistical analysis. Allergy, asthma, and clinical immunology. Official Journal of the Canadian Society of Allergy and Clinical Immunology, 9(1), 46.

Hemilä, H. (2017). Vitamin C and infections. Nutrients, 9(4), 339.

Johnston, C.S., Barkyoumb, G.M., & Schumacher, S.S. (2014). Vitamin C supplementation slightly improves physical activity levels and reduces cold incidence in men with marginal vitamin C status: A randomized controlled trial. Nutrients, 6(7), 2572-2583.

Ran, L., Zhao, W., Wang, J., Wang, H., Zhao, Y., Tseng, Y., & Bu, H. (2018). Extra dose of vitamin C based on a daily supplementation shortens the common cold: A meta-analysis of 9 randomized controlled trials. BioMed Research International, 2018, 1-12.

Sasazuki, S., Sasaki, S., Tsubono, Y., Okubo, S., Hayashi, M., & Tsugane, S. (2006). Effect of vitamin C on common cold: Randomized controlled trial. European Journal of Clinical Nutrition, 60, 9-17.

Van Straten, M., & Josling, P. (2002). Preventing the common cold with a vitamin C supplement: A double-blind, placebo-controlled survey. Advances in Natural Therapy, 19(3), 151-159.

Appendix

Research Matrix

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Taking care of one’s body is necessary to lead a healthy, long, and prosperous life. Many factors contribute to an individual’s overall health, including their living conditions, daily routine, the amount of exercise, and, of course, their diet. Having a balanced food intake to supply the body with the building blocks it requires to function is especially important, with many possible food options available. However, sometimes eating healthy can prove to be difficult, and people might want to enrich their diets with supplements and vitamins. Vitamins E and D are considered by many to be a staple of a healthy lifestyle and they are believed to present various benefits. This post attempts to discuss the benefits, as well as the detriments, of using E and D vitamin supplements. The final goal will be to determine whether everybody should enrich their diet with them.

First of all, it is important to note the positive effects vitamin D has on human health. Vitamin D, usually found in fish and some plants, ensures that the body absorbs calcium and one’s bones grow properly. It can be obtained from food and exposure to sunlight, as well as various supplements. Many foods rich in vitamin D can be expensive, or unavailable throughout the year, so taking supplements can be a good alternative. The usage of vitamin D supplements, in my opinion, is also vital to maintaining a healthy lifestyle in places without much sunlight. Furthermore, it has been proven that vitamin D intake and the usage of supplements can decrease all-cause mortality rates in adults and elderly people (Simon, 2008). I think that everybody should enrich their diet with vitamin D, as its effects are beneficial to an individual’s well-being.

As for vitamin E, on the other hand, the matter is more complicated. Contained primarily in various nuts and fruit, it helps the human body to slow the aging process and protect the cells from damage. Not many people eat nuts on a daily basis, so the consumption of supplements may be justified. The important factor of the vitamin E supplement usage is the risks associated with it. The National Institutes of Health reports have shown that vitamin E overdose can lead to an increased risk of hemorrhagic stroke (U.S. Department of Health and Human Services). I think that supplementing your diet with vitamin E can prove helpful, but it is important to regulate its intake. Overall, I think that everybody who cannot afford to acquire vitamins E and D from their foods should use supplements, although in strictly regulated amounts.

Vitamin C has always been regarded as an irreplaceable part of the diet, with its many positive effects on the human condition. The vitamin, contained within various fruits and vegetables, most notably oranges and lemons, is said to protect against various diseases and cardiovascular diseases. Many people regard it as the best solution for the common cold, and others go as far as to name it a viable treatment method for COVID-19. In this post, I will try to examine vitamin C’s effects on both of these illnesses.

According to researchers, vitamin C has no traceable effect on preventing or treating common cold. Quoting a paper on the subject, it should be mentioned that “No consistent effect of vitamin C was seen on the duration or severity of colds in the therapeutic trials” (Hemilä & Chalker, 2013, p. 2). As a matter of fact, no major correlation has been found between consuming vitamin C and reduced duration of the common cold (Hemilä & Chalker, 2013). The authors, however, note, that due to its wide availability, individuals might still get some benefits from using vitamin C even if the result is not guaranteed. Speaking of Covid-19, scientists have found no correlation between it and vitamin C either. The authors of an article on the topic state that while vitamin C improves the body’s immune function, it cannot protect one from contracting the Corona Virus (Shoemaker, 2020). The assumption of its effectiveness came from Chinese doctors using vitamin C to improve the lung function of COVID-19 patients. Such an application of the vitamin does not have an evident effect on one’s body. For now, the potential benefits of vitamin C as a treatment for the Coronavirus are not proven and are still being tested.

Overall, I would say that there does not seem to be sufficient evidence to say that vitamin C helps with the prevention and treatment of either the common cold or COVID-19. There are no visible health risks associated with its intake in moderate amounts, however, so any individual can try to examine its effectiveness for themselves. The most effective treatment for both diseases at the moment is a combination of preventive measures taken to not contract a disease in the first place.

References

Hemilä, H., & Chalker, E. (2013). Vitamin C for preventing and treating the common cold. The Cochrane database of systematic reviews. Web.

Shoemaker, S. V. (2020). Can Vitamin C Protect You from COVID-19? Healthline. Web.

Simon, J. A. (2008). Review: vitamin D supplementation decreases all-cause mortality in adults and older people. Evidence-Based Medicine, 13(2), 47–47. Web.

U.S. Department of Health and Human Services. Office of Dietary Supplements – Vitamin E. NIH Office of Dietary Supplements. Web.

Nowadays, there exists a great variety of medications aimed at treating a particular health issue. Due to their number, some of them have quite similar names that can potentially confuse both the patient and pharmacist (Levinthal, 2014).

Sometimes, these drugs can be mistaken due to their common active substance, so they do not do serious harm to the human body. Frequently, however, medication titles can have a direct commercial purpose, as they are created in order to be easily memorized. Such cases can lead to severe health issues and medical errors. According to the statistics published in 2016, the medical mistake was a third leading death cause in the US (Makary & Daniel, 2016). Although misspelled medications constitute a minor part of medical errors, they are still hazardous to people’s health.

In order to define ways to combat the issue, it is important to dwell upon the reasons these errors occur in the first place. According to data, some of the major problems behind medication prescription are legibility and spoken orders (Norman, 2018).

The first matter is highly individual as it concerns doctor’s handwriting that can easily be misread by a pharmacist. The second issue, on the contrary, is an example of medical negligence, as patients are not supposed to know the detailed information on various drugs, and thus, they get confused. As this issue concerns not only medication names but diagnosis and patients’ personal information as well, the healthcare system issue should be completely reconsidered. The best option in terms of records optimization is by creating a working electronic database. By doing so, pharmacists could have electronic access to a patient’s prescription and the probability of medical error would be as minimal as possible.

References

Levinthal, C. F. (2014). Drugs, behavior, and modern society. London, UK: Pearson Education.

Makary, M. A., & Daniel, M. (2016). Medical error – the third leading cause of death in the US. BMJ, i2139. Web.

Norman, A. (2018). “Minor” errors in medical records can have major consequences. Web.

Cancers have become common in different parts of the world today. Most of the patients reporting such terminal conditions cannot explain their primary causes. The article “The Vitamin Myth: Why We Think We Need Supplements” offers a detailed analysis of this problem and provides additional suggestions that can guide more people to lead healthier and longer lives.

Summary of the Article

The author begins by referencing past studies to explain how vitamin supplements are associated with increased risk for various medical conditions, including cardiovascular disease and cancer. Most of the consumers of such products lead shorter lives. The history and achievements of Pauling stand out since he managed to win two unshared Nobel Prizes and made significant contributions to the field of molecular biology and chemistry. His revolutionary works and findings were inspirational and capable of changing the world forever. However, Pauling eventually became the most infamous scholar because of vitamin C (Offit, 2013). This outcome was after he published the book Vitamin C and the Common Cold to encourage more people to be taking round 3,000 mg of vitamin C every single day (Offit, 2013). The Linus Pauling effect eventually became a reality since by 1975 over 50 million Americans were following his advice.

Despite the subsequent studies challenging Pauling’s views, he was always keen to oppose their findings. He went further to support the use of vitamin C as the best hope for cancer patients. However, researchers later realized that vitamin C was incapable of treating cancer. Subsequent investigations at the Fred Hutchinson Cancer Research Center revealed that several cancer patients subjected to vitamin A and betacarotene died prematurely at a rate of 17 and 28 percent respectively (Offit, 2013). Despite his views and belief that vitamins did not have side effects, Linus Pauling and his wife died of cancers even though they took vitamin supplements frequently.

Key Moments from the Article

The selected article provided outstanding passages, examples, and moments that stood out for me. First, I observed that Pauling was a dedicated scholar and researcher whose inventions and revolutionary ideas transformed the fields of biology and chemistry forever. Second, his demise due to cancer was a testimony that his prolonged overuse of vitamins was linked to the disease. This revelation was a clear indication that the intake of vitamins was dangerous and capable of triggering the occurrence of cancer (Offit, 2013). Third, the presented information reveals that many people today continue to rely on the use of vitamin supplements despite the glaring evidence. Individuals should consider these emerging issues if they are to make conclusive decisions regarding the use and place of vitamin supplements in the field of health.

Author’s Perspectives

Several perspectives and arguments in this article are significant and interesting to any reader. The first one is that Pauling’s achievements are quite outstanding and capable of encouraging more people to focus on their future goals. Professionals in the fields of medicine and science could emulate this kind of dedication if they are to achieve their maximum potential. The second interesting issue is the argument that vitamin supplements are dangerous and capable of triggering the development of cancer (Offit, 2013). This key moment is worth reading since the author has relied on past research findings to support the argument. The ideas are agreeable since the studies are authentic or from recognizable institutions in the fields of oncology, science, and biomedicine.

The third argument is that the global society remains deviant when it comes to the dangers associated with the overuse of vitamin supplements. Finally, the idea that most of the plant and animal sources of proteins and vitamins are adequate to support a healthy life appears plausible since it provides a solution to this debate. Consequently, Offit (2013) indicates that “nutrition experts contend that all we need is what’s typically found in a routine diet” (p. 1). Individuals who consider these issues will transform their experiences and eventually lead longer lives.

Personal Response

The presented insights in this article are worth reading and timely since they can guide me to become a competent provider of high-quality services to my patients. The current use of multivitamins qualifies as a major concern that different stakeholders should take into consideration. The findings outlined in the work expose some of the risks and dangers associated with such supplements. Experts in the field of medicine should, therefore, present evidence-based ways to guide and allow their patients to embrace the concept of a balanced diet (Offit, 2013). Such a practice will reduce chances of developing cancer, thereby setting the stage for a longer and healthier life.

Closing Comments

In conclusion, the arguments, ideas, and observations in the selected reading are inspirational and capable of influencing a paradigm shift regarding the marketing, prescription, and use of multivitamin supplements. The audience will appreciate the fact that such drugs are capable of increasing the risk for hypertension and cancer. Individuals should consider the need to explore and read widely if they are to acquire additional ideas regarding the benefits and dangers of vitamins in medical practice.

Reference

Offit, P. (2013). The vitamin myth: Why we think we need supplements. Health. Web.

Abstract

The associated with vitamin D and calcium publications are primarily based on their respective supplements’ health effects. They have clarified an interesting scenario regarding the consumption of these elements. The landscape of vitamin D and Ca can be observed across different populations. To test the prevalence of vitamin D and Ca deficiency, similarities, and differences, alongside their health benefits, a cross-sectional study was deliberated in Sharjah, United Arab Emirates. The research established that these elements are synergistic and integral for immunological functions, including the formation of healthy teeth. However, they displayed characteristic physiological differences. Sources and resources used in the study were obtained from internet sources. Sites like Google Books, Google Scholar, and EBSCOhost were used to acquire possible research information. Intending to seek facts and evidence surrounding the health benefits of Ca and vitamin D, the research established research gaps like the high prevalence of vitamin D and Ca deficiencies among the study group regardless of the increasing literacy and education levels.

Vitamin D and Calcium

Introduction

There have been numerous publications associated with the various aspects of vitamin D and calcium. The studies primarily focus on the physiological and therapeutic aspects of the micronutrient. The florid scientific literature does not eliminate the uncertainty on numerous issues. For example, there is no consensus on the importance of vitamin D and calcium in people’s health and well-being. Endless debates have been highlighted, including the standard means of measuring the 25-hydroxyvitamin D (25(OH) D), precursors, and metabolites. Excessive calcium absorption could lead to nephrolithiasis and nephrocalcinosis¹. The other debate is associated with hypovitaminosis in the general population concerning a specific clinical condition such as pregnancy and health condition. The research will focus on vitamin D and calcium issues concerning the modalities used to ensure sufficiency and health benefits. The target group will be the United Arab Emirates population that has faced significant health issues associated with the nutrients.

Literature Review

Roles of Vitamin D in the Body

Vitamin D is essential for physiology and anatomy. First, vitamin D is preventing rickets’ development. The formation of healthy bones is dependent on this element’s presence, but it is also influenced by calcium. Vitamin D enhances dietary calcium intake, a mineral integral to the formation of such bust bones. Secondly, it promotes the physiology of parathyroid glands. Because they balance calcium levels via the kidney, vitamin D is directly involved in homeostasis maintenance². Calcium and/or vitamin D insufficiency condition parathyroid glands to break down bones to obtain calcium or vitamin D.

Functions of Ca

While 99% of it is located in teeth, bones, calcium is also found in body fluids, blood, tissues, and nerve cells. The intake of calcium helps with the coagulation, healthy forming of bones, sending and reception of nerve signals, squeezing and relaxing muscle cells, releasing hormones and other chemicals essential for body functioning, and maintaining a regular heartbeat. After a human being stops growing, calcium is vital to maintaining the bone structure. The mineral is also crucial in ensuring that the bone density growth is minimal. Noteworthy, diminishing bone density is a natural part experienced in the aging process. The mineral is also essential in the cardiovascular system because it is one of the agents supporting blood clotting. Some studies have correlated much calcium intake with a low prevalence of high blood pressure³. The rationale behind the indication is that calcium is responsible for relaxing the muscles surrounding blood vessels.

Effects of Vitamin D and Ca Deficiency in the Body

Poor Immunity, Allergic Responses, and Enhanced Weight Loss

Their physiological functions inform the effects of Vitamin D-Calcium deficiencies. First, Vitamin D promotes immunity and is expressed on immunologic cells such as B and T cells and antigen. Secondly, Vitamin D can help prevent various infectious diseases; therefore, it can improve current global public health associated with the COVID-19 pandemic⁴. Calcium is required for activating the immune system when it enters immune cells, especially those involved in allergic responses. In lymphocytes, calcium ions act as intermediaries that trigger lymphocytes’ actions. Vitamin D and calcium combination enhances calcium absorption, hence a necessity among obese individuals because of enhanced weight loss. Current evidence on vitamin D and calcium combination also cite helping with the weight loss. The latter indirectly reduces comorbidities like hypertension or diabetes. Therefore, vitamin D and calcium deficiency leads to low immune and allergic responses. The rationale of this argument regards the pivotal roles they play in enhancing immunity and allergic reactions.

Diseases like Osteoporosis and Poor Related Physiological Functions

Vitamin D and calcium are equally integral to the formation of healthy bones and teeth, and this vitamin insufficiency leads to poor Ca absorption. Because both of these elements are similarly essential, in case of deficiency, bones will be degraded, as well as physiological functions like the formation of bone marrow and immune cells.

Gaps in Existing Literature

The following are some of the gaps in the literature;

1. 1. High rates of supplement ignorance across the sample population
   2. Even though the global community is becoming more literate, vitamin D and calcium deficiencies are equally increasing. The scene is quite surprising because increasing literacy across the global population should inform the appreciation of vitamin D and calcium supplements.

1. Medical professionals’ response and roles in addressing or stressing the importance and benefits of supplements across the study group of the global population.
2. Vitamin D and calcium interplay and their concomitant/synergistic roles in facilitating human health and well-being.
3. The increasing vitamin D and calcium deficiency despite increasing literacy across the global population.

Aims of the Paper

The primary aim of this paper is to clear the debate surrounding vitamin D and calcium supplements. The discussion covers the prevalence of vitamin D and calcium deficiency in the UAE. The discussion is based on a practical approach via a cross-sectional study in Sharjah to display vitamin D and calcium prevalence, alongside the specimen’s health effects.

Methodology

Research Design

A cross-sectional research design was used to study the specimen, n=480, in Sharjah. They were randomly selected from Sharjah’s population. The study grouped aged between 5 to 79 years. The actual research was conducted at the American University of Sharjah, UAE⁵. Ethical values and competence are crucial elements in such studies. A mixed methodology was used in the survey to acquire qualitative and quantitative data about the topic. Qualitative and quantitative data is necessary to account for a given phenomenon according to the figures captured among the participants⁶. An open-ended questionnaire was administered to the patients to obtain data on their condition. They elaborated on their health based on vitamin D deficiency. A survey was also conducted across Sharjah’s medical facilities to establish the trends and patterns of consumption of drugs concerning vitamin D deficiency and calcium-related complications. The survey stretched to the business sector to obtain statistical data and qualitative comments from supplement dealers. The study majorly discovered demographic information on the prevalence of vitamin D deficiency, their dietary practices, exposure to the sun, immunity, and comorbidities related to low immunity. The data captured the specific figure of Sharjah’s vitamin D deficient individuals. The latter was also tied to calcium-related health issues like osteoporosis, low immunity, and weak teeth.

Sources

A demonstration of the research and search phrases are highlighted in Fig. 1. The process involved searching through databases to identify critical literature. Some of these databases and research browse include ‘EBSCOhost,’ ‘Google Books,’ ‘Science Direct,’ and ‘Google Scholar.’ However, the search was run using essential words and phrases relevant to the research topic. These are ‘vitamin D,’ ‘calcium mineral,’ ‘Hypovitaminosis D,’ ‘Osteomalacia,’ ‘Osteoporosis,’ ‘Calcium,’ and ‘Vitamin.’ Age and relevance filters were further used to qualify or discredit material found using this technique. For instance, papers were only considered if published after 2015 to increase data relevance and accuracy. Twelve articles were eventually considered after critical evaluation for relevance to the study.

Research Agents Used and the Wording Employed to Acquire the Sources

The following flow chart shows research agents and wording used to acquire data in the research;

Results

The Prevalence of Vitamin D and Calcium Deficiency in UAE

UAE’s vitamin D deficiency victims rangers between 50% to 90% of the total population who suffer from osteoporosis⁷⁸.The study found that at least 90% of the participants were suffering from vitamin D deficiency. The conclusion that 90% of the population experienced vitamin D deficiency was drawn from the results’ multidimensional elements. The most prevalent aspect of vitamin D deficiency across the specimen were fatigue, painful bones, and muscle weaknesses. Both young and elderly participants complained about the complications mentioned above. They were registered to have consumed painkillers and medicines addressing bone-related disorders. The medical practitioners and clinicians in the medical facilities commented on the same by asserting the vitamin D deficiency resulted in those conditions due to low calcium absorption. Data collected from medical facilities and supplement dealers indicated low supplement consumption. While 92% of supplement dealers cited caution among Sharjah’s residents on safety issues surrounding the supplements, medical facilities stressed that UAE residents would never consume supplements whatsoever. The study group indicated an attitude and negative perception of the supplements based on perceived adverse effects and health implications conferred by supplements. Participants also stated that they were not exposed to the sun.

Nutritional entries often fail to emphasize the importance of calcium as a singular mineral in the human body. Most studies are quick to divert from this topic after highlighting the essential role of vitamin D and calcium deficiency instances. Nimri notes that “Vitamin D deficiency is most often associated with inadequate calcium intakes and causes bone degeneration or osteoporosis”⁹.Therefore, Ca deficiency cases are overshadowed by vitamin D deficiency issues, making it difficult to locate information for this statistic alone. However, Nimri explains the decrease in Ca intake among youth by the popularity of carbonated drinks over healthier choices like milk. Therefore, cases of vitamin D are a manifestation of Ca deficiencies that contributes to weak bones.

The Prevalence of the Usage of Vitamin D and Calcium Supplements

While 70% of the study group were unaware of the importance of sun exposure in acquiring vitamin D, 30% were unconcerned with exposure to the sun. 60% of the study group indicated that they never consume foods rich in vitamin D like fish liver oils and fatty fish like tuna, salmon, mackerel, and trout. Laboratory tests on calcium deficiency were tied to vitamin D deficiency. Individuals composing 90% of participants found with vitamin D deficiency were found with calcium deficiency. The figure indicated a direct relationship between vitamin D deficiency and calcium deficiency. 20% of the affected population was subjected to treatment to test the parathyroid organs’ effectiveness and roles.

The Medical Effects of the Supplements

Medical Effects of Ca Supplements

1. Gas
2. Constipation
3. Bloating
4. Prevention against osteoporosis by inhibiting osteopenia

1. Formation of strong teeth and bones

1. Weight loss
2. Regulation of phosphorus, magnesium, and potassium in the blood

Medical Effects of Vitamin D Supplements

1. Formation of strong teeth and bones
2. High calcium absorption

1. Regulates phosphorus and calcium absorption

1. Boosting immunity and preventing depression
2. Promoting weight loss

Similarities Between Vitamin D and Calcium

1. Maintaining homeostasis of the skeletal system.

1. Formation of strong bones and teeth

2. Immunity

1. 1. A healthy skeletal system produces vibrant blood cells.
   2. White blood cells are integral to fighting diseases.
   3. The body is protected from diseases like
      1. Cancer
      2. Hypertension
      3. Musculoskeletal diseases¹⁰

3. The two elements need and/or rely on each other to deliberate their functions
4. They can be supplied by diet and supplements.

Differences Between Vitamin D and Calcium

Vitamin D and calcium differences regard physiological elements and sources. While vitamin D is freely and naturally available from the sun and enhances Ca absorption, the final is integral for forming healthy teeth and bones. Unlike vitamin D, Ca not be obtained freely from the sun. It can be obtained from diet and supplements.

Discussion

Al Kattub (2017) argues that vitamin D deficiency predisposes individuals to heart disease, kidney disease, hypertension, liver disease, and disease¹¹. The argument encapsulates a multidimensional element on the subject because of Vitamin D and Calcium interaction and immunity development roles. Further, organ failure is another contributing factor to the conditions mentioned above. Vitamin D is needed to facilitate calcium absorption from dietary foodstuffs, and calcium is required in order to form a robust immune system. Therefore, individuals suffering from vitamin D deficiency will undoubtedly suffer from calcium deficiency and equally low immunity. Sharjah’s studied population is a classic reflection and illustration of the perspective issued above. The community stressed that they hardly consume vitamin D rich foods mentioned earlier and are do not bask in the sun. The sun is a free source of vitamin D. Therefore, they are not immune to the health complications and developmental problems associated with vitamin D and calcium deficiency.

Conclusion

Vitamin D and calcium is found to be an element among the study population. With the laboratory tests revealing abnormally minimal metabolites and precursors of 25-hydroxyvitamin D and the participants’ confession of minimal and/or no consumption of vitamin D rich foods, the conclusion that the debate surrounds negligence and negative perception of supplements is inevitable. 90% of the specimen would have been saved via supplement consumption. However, the negative perception of supplements prevented their consumption and informed unsatisfactory purchases from dealers. Medical and health issues found among the participants are an image of caution and safety issues posited regardless of whether they are relevant. Arguably, the safety issues and concerns are somewhat blown out of proportion because the supplements pass quality tests and safety measures and guidelines established to guide their manufacturing and production.

References

Abrahamsen, B. (2017). The calcium and vitamin D controversy. Therapeutic Advances in Musculoskeletal Disease, 9(5), 107-114. Web.

Baran, M., & Jones, J. (2016). Mixed methods research for improved scientific study.

Ferretti, M., Cavani, F., Roli, L., Checchi, M., Magarò, M. S., Bertacchini, J., & Palumbo, C. (2019). Interaction among Calcium Diet Content, PTH (1-34) Treatment and Balance of Bone Homeostasis in Rat Model: The Trabecular Bone as Keystone. International Journal of Molecular Sciences, 20(3). Web.

Khazai, N., Judd, S. E., &Tangpricha, V. (2008). Calcium and vitamin D: skeletal and extraskeletal health. Current rheumatology reports, 10(2), 110-117.

Kuttab, J. (2017). Vitamin D deficiency could cause deadly diseases, warn UAE doctors. Web.

Liu, M., Yao, X., & Zhu, Z. (2019). Associations between serum calcium, 25(OH)D level and bone mineral density in older adults. Journal of Orthopaedic Surgery and Research, 14, 1-7. Web.

Nimri, L. F. (2018). Vitamin D status of female UAE college students and associated risk factors. Journal of Public Health, 40(3), e284-e290.

Palacios, C., & Gonzalez, L. (2014). Is vitamin D deficiency a major global public health problem?. The Journal of steroid biochemistry and molecular biology, 144, 138-145.

Reid, I. R., &Bolland, M. J. (2019). Controversies in medicine: the role of calcium and vitamin D supplements in adults. Medical Journal of Australia, 211(10), 468-473.

Sahay, M., & Sahay, R. (2012). Rickets–vitamin D deficiency and dependency. Indian journal of endocrinology and metabolism, 16(2), 164.

Shakoor, H., Feehan, J., Al Dhaheri, A. S., Ali, H. I., Platat, C., Ismail, L. C.,… & Stojanovska, L. (2020). Immune-boosting role of vitamins D, C, E, zinc, selenium and omega-3 fatty acids: could they help against COVID-19?. Maturitas.

Footnotes

1. Abrahamsen, B. (2017). The calcium and vitamin D controversy. Therapeutic Advances in Musculoskeletal Disease, 9(5), 107-114. Web.
2. Liu, M., Yao, X., & Zhu, Z. (2019). Associations between serum calcium, 25(OH)D level, and bone mineral density in older adults. Journal of Orthopaedic Surgery and Research, 14, 1-7. Web.
3. Ferretti, M., Cavani, F., Roli, L., Checchi, M., Magarò, M. S., Bertacchini, J., & Palumbo, C. (2019). Interaction among Calcium Diet Content, PTH (1-34) Treatment and Balance of Bone Homeostasis in Rat Model: The Trabecular Bone as Keystone. International Journal of Molecular Sciences, 20(3) Web.
4. Shakoor, H., Feehan, J., Al Dhaheri, A. S., Ali, H. I., Platat, C., Ismail, L. C.,… & Stojanovska, L. (2020). Immune-boosting role of vitamins D, C, E, zinc, selenium, and omega-3 fatty acids: could they help against COVID-19. Maturitas.
5. Nimri, L. F. (2018). Vitamin D status of female UAE college students and associated risk factors. Journal of Public Health, 40(3), e284-e290.
6. Baran, M., & Jones, J. (2016). Mixed methods research for improved scientific study.
7. Nimri, L. F. (2018). Vitamin D status of female UAE college students and associated risk factors. Journal of Public Health, 40(3), e284-e290.
8. Palacios, C., & Gonzalez, L. (2014). Is vitamin D deficiency a significant global public health problem? The Journal of steroid biochemistry and molecular biology, 144, 138-145.
9. Nimri, L. F. (2018). Vitamin D status of female UAE college students and associated risk factors, e284.
10. Khazai, N., Judd, S. E., &Tangpricha, V. (2008). Calcium and vitamin D: skeletal and extraskeletal health. Current rheumatology reports, 10(2), 110-117.
11. Kuttab, J. (2017). Vitamin D deficiency could cause deadly diseases, warn UAE doctors. Web.

Introduction

The extent to which a given substance can destroy an organism or part of the organism is known as toxicity. A substance can harm an entire organism, an organ, or a cell. The effects of a substance on an organism are usually dependent on the dose taken, this is because everything is poisonous if taken in massive amounts. Toxins are classified as chemical, biological and physical (Davenport and Weatherspoon, 1999, p.7)

Vitamin D

Vitamin D is a fat-soluble vitamin that exists in various forms mainly vitamin D2 and D3. The chemical formula for Vitamin D is C28H440 for vitamin D2 and C27H440 for vitamin D3. Vitamin D toxicity occurs when the concentration of serum in blood D 25(OH) D rises to very high levels.

The LD50 for vitamin D has been found to be 42 mg/kg in rats, 42.5 mg/kg in the mouse, and 80 mg/kg in dogs. As far as the dose-response curve is concerned, the toxicity threshold level for vitamin D is 200-250 mg/nmol/L (500-750 nmoI/l) while the upper limit is 100 mg/L (250 nmoI/L). This leaves a safe margin of 100 mg/L (250 nmoI/L). The curve takes a sigmoid shape

The NOAEL is the upper limit which courses no adverse effects and for vitamin D it is 100 mg/L (250 nmoI/L). The toxic dose for vitamin D is a consumption of more than 4000 IU (1000mcg) per day. It is recommended that vitamin D be taken in doses of less than 4000 IU (1000 mcg) per day. The acceptable allowance is the safe margin between the upper limit and the threshold which is 100 mg/L (250 nmoI/L).

Vitamin D toxicity causes excess calcium in urine and blood. The body controls vitamin D intake from the sun hence toxicity comes from food supplements. Detoxification entails taking in less calcium and avoiding very hot sunshine. (Dowd and Stafford, 2008, p.57)

Round up glyphosate

This is a form of herbicide used to kill weeds. The LD50 of this herbicide is over 5000mg/kg in rats and rabbits. The chemical formula of round-up glyphosate is C3H8NO5P. The response curve is a sigmoid shape. The lethal dose for this herbicide is about three cups of nasty bitter round-up. The NOAEL is 6.4 (Harte, 1991, p.323)

This is a poisonous substance and hence it is not recommended for daily intake. This chemical affects body weight and male fertility in animals. The target organ is the male reproductive system. Heterologous genes are used to detoxify it from the soil. This simply entails introducing a foreign gene in the crop to detoxify round-up glyphosphate from the soil.

Nicotine

This is a natural plant-based insecticide. The chemical formula for nicotine is C10H14N2. The LD50 for nicotine is 50kg/mg in the rat. The lethal dose for nicotine in humans is 0.9 mg/kg but that of dogs is 9.2 mg/kg. In pigeons, the lethal dose is 75 mg/kg. (Yamamoto and Cassia P. 3).

NOAEL 1.14 mg/kg per day. This is a powerful insecticide and hence should not be taken in. nicotine insecticide affects the body arteries.

Sodium nitrate

This is a food preservative commonly used in preserving meat. The chemical formula is NaNO3. The lethal dose for sodium nitrate is 22mg/kg.

The LD50 in rats is 1267 mg/kg. Sodium nitrate may damage human blood, if ingested it’s dangerous, damage the skin in case of close contact and irritates if inhaled. (Taylor, 2001, p.203) The response curve for this substance is a sigmoid shape. A daily intake of 0-0.5 mg/kg daily is a safe range. Sodium nitrates can be removed from the body by fasting. The NOAEL is 1820 mg/kg BW/day.

Conclusion

Toxins are dangerous to any living organism, and any chemical or substance if taken in large quantities become poisonous. It’s recommended that whatever substance is taken in should be in the right quantities to avoid harming the body.

Reference list

Davenport, M, G and Weatherspoon, p. 1999. Working with toxic older Adults. New York Springer publishing company.

Dowd, J. and Stafford, D. 2008. The vitamin D cure. New Jersey: Wiley Publications.

Harte, J. 1991. Toxics A-Z. Los Angeles: University of California press.

Taylor, R, E. 2001, lethal mist, New York: Nova science publishers.

Yamamoto, I. and Casida E, C.nicotinoids insecticides and the nicositinic acetylcholine receptor. Hong Kong: Sprinter vegar publishers.

Abstract

Since previous studies suggest that people with cystic fibrosis and pancreatic insufficiency tend to be deficient in fat-soluble vitamins like vitamin A, the study endeavored to establish whether vitamin A intake could lead to elevation of serum retinol levels in the blood. Serum retinol levels were measured in 78 participants who were between 8 to 25 years. Assessments were done using high-performance liquid chromatography. These were subsequently compared to NHANES data obtained from participants having similar ages. Measurements of vitamin A intake, anthropometry, and FVE1 were undertaken. Assessment of these measurements was then done. Fifty-eight percent of the participants did not feature in the NHANES reference range. Intake of vitamin A was above the recommended dietary allowance of 600+431% (Maqbool et al 2008). There was no correlation between serum retinol and vitamin A intake, age of the participants and their sexes. However, there was an inverse correlation between serum retinol with weight and height of z-scores in participants with Cystic Fibrosis. The study, therefore, arrived at a conclusion that intake of vitamin A and serum level was high in participants with CF and PI.

Introduction

The study was initiated courtesy of a previous study whose findings showed high retinal concentration in individuals with cystic fibrosis and pancreatic insufficiency which was contrary to the belief that these conditions make such people fat-soluble vitamin malabsorption. The study intended to state vitamin A status and to approve or disapprove the initial research findings with participants having a broader age range.

Materials and Methods

Participants were both children and young adults whose ages ranged between 8 to 25 years. They both exhibited CF and PI conditions. They were picked from pediatric and CF facilities. An inclusion criterion was majorly anchored on the diagnosis of CF and PI using standard methods. Participants with other major medical conditions were never allowed to take part in the study likewise to those who had less than 40% FEV1 (Maqbool et al 2008). After the collection of serum, retinol analysis was done by HPLC. The levels were then compared with those of NHANES’ ranges from age-equivalent white participants. Heights and weights were measured using a stadiometer and a digital scale. Z-scores were calculated. Pulmonary function was worked out using standard methods. Dietary intake for 3-day weighed food was determined by research technicians. Vitamin A intake in participants with cystic fibrosis was corroborated. Test for normality and skewness was conducted for all variables. Group comparisons were tested with the help of either Student’s T-test or the Wilcoxon rank-sum test. Presentation of data was done in terms of mean+ or –standard deviation, the calculated median values, and range. In testing significant variation between variables, spearman rank correlations were employed.

Results

The 78 participants who took part in the study all had serum retinol, anthropometry, and FEV1. Nine percent of the participants took part in the current research and the pre-adolescent study. There was dietary intake data for 53 participants. Subjects who had no dietary data had lower percentages of FEV relative to those with complete dietary data. 42% of the participants had serum retinol whereas 58% of them had concentrations above NHANES’ reference range. No participant with CF and PI possessed serum retinol below the lower reference range. Vitamin A that was derived from food and supplement was 608±431% RDA. A whopping 67% was derived from supplements.

Discussion

With the help of NHANES reference data, it was found that 58% of participants with CF and PI had high levels of serum retinol concentrations. These findings have raised concerns as to the possibility of the risk of vitamin A toxicity in the population with cystic fibrosis. Vitamin A helps in maintaining cell integrity, encourages cell growth, and enhances the operation of the immune system. Preformed retinoids and pro-vitamin A carotenoids serve immune functions. A major limitation to the study was that it involved the use of cross-sectional design and that analysis of vitamin A in people with cystic fibrosis was secondary in their bone health.

Conclusion

The study, therefore, arrived at a conclusion that intake of vitamin A and serum level was high in participants with CF and PI.

Reference

Maqbool, A., et al. (2008). Vitamin A intake and elevated serum retinol levels in children and young adults with cystic fibrosis. Journal of Cystic Fibrosis, 7, 137–141.

Introduction

One of the major health problems that go unnoticed is Vitamin D deficiency. Limited exposure to sunlight and decreased dietary intake, increased skin pigmentation, and geographical location causes vitamin D deficiency (Reichrath, 2008). Lack of vitamin D causes rickets in children; it causes osteomalacia in adults besides having long lasting effects in human health (Darke, 2006). Vitamin D comes from direct sunlight and naturally, from animal products like egg yolks and fish liver oils.

Research Objective

The research aims at reviewing the various factors that contribute to vitamin D deficiency between children and adults and the various measures put in place to prevent diseases such as rickets among children. Examination of Vitamin D was done against the percentage of calcium intake.

Importance of the subject

The subject is important because vitamin D is essential in the development and growth of a healthy human skeleton from birth to death. Vitamin D maintains calcium homeostasis in the body by increasing the ability of the intestines to absorb calcium (Ernesto, 2001). Lack of vitamin D in the body affects the way different organs in the body operate such as the kidney, cardiovascular systems, and skeletal muscles. It can cause various diseases and pathological conditions, for example, cancer, and type II diabetes (Holick, 2011). Adequate vitamin D is beneficial to human health. It reduces the risk of contracting bone diseases, reduces the extent of pain, heart diseases, autoimmune and cognitive function (Hauschka, 2009). The subject is also important since it highlights the predisposing factors of Vitamin D and ways of eradicating it to stop diseases like rickets from affecting infants and children in the world (Steiner, 2009).

Hypothesis

1. Does vitamin D deficiency cause prostate cancer among men? Prostate cancer is one of the diseases causing deaths among men. This is due to decreased synthesis of vitamin D. there is an inverse correlation in some of the countries between mortality rates caused by prostate cancer and ultra-violet radiation. The hypothesis is backed by the antitumor properties exhibited by vitamin D, and may give way to new ways of researching prostate cancer (Schwartz, 1990, p. 25).
2. Atmospheric acid containing SO₂ and crystals of sulfate lead to Vitamin D deficiencies in crowded places such as cities, and it increases chances of breast cancer (Chappleton, 2008).
3. Does the human body have the ability to reduce vitamin D in order to deal with the increased amount of phosphorous in our diet? It is argued that every 1 mg/dL increase in 24h phosphorous levels in the human blood leads to decrease in naturally available vitamin D by a margin of -19 pg/dl although the various variables like magnesium and calcium intake remain the same (Hochberg, 2003).
4. Is it true that an infant’s vitamin D at birth depends on the amount of vitamin D of the mother (Holick, 2007, p. 35)?

Research Questions

What is the major cause of vitamin D deficiency among women?

What steps are there to reduce vitamin D deficiency between women and children?

What is the cost implication of vitamin D deficiency in the economy of a country?

What is the role of women and children in eradicating vitamin D deficiency?

Conclusion

Vitamin D deficiency, caused by various factors, compounded together. Many remedies are available to stop Vitamin D deficiency among women and children and among the general populations. Lack of vitamin D is associated with various diseases some of which have no cure such as cancer.

References

Chappleton, N. (2008). Dietary Reference Intakes for Calcium and Vitamin D. Melbourne: National Academies Press.

Darke, J. (2006). Vitamin D deficiency and osteomalacia. New York: H.M.S.O.

Ernesto, I. (2001). Calcium Homeostasis. London: Springer.

Hauschka, R. (2009). Nutrition. New York: Rudolf Steiner Press.

Hochberg, Z. (2003). Vitamin D and Rickets. Boston: Karger Publishers.

Holick, M. (2007). Vitamin D Deficiency. Web.

Holick, M. (2011). Vitamin D: Physiology, Molecular Biology, and Clinical Applications. London: Springer.

Reichrath, J. (2008). Sunlight, Vitamin D and Skin Cancer. London: Springer.

Schwartz , H. (1990). Is vitamin D deficiency a risk factor for prostate cancer? (Hypothesis). Web.

Steiner, R. (2009). Nutrition: Food, Health, and Spiritual Development. New York: Rudolf Steiner Press.

Annotation #1

Buttigliero C, Berruti A. Prognostic role of vitamin D status and efficacy of vitamin D supplementation in cancer patients: a systematic review. Oncologist. 2011; 16(9): 1215-1227.

Summary

The scholars in this article were interested in determining the relevance of hypovitaminosis D and vitamin D supplementation for patients with cancer. According to scholars, there has been a controversy about the actual benefits of vitamin D to patients suffering from cancer. The scholars note that cancer is currently one of the leading causes of death in the world. What is more worrying is the fact that it is not yet clear what actually causes some types of cancer. Researchers all over the world have been working tirelessly to come up with measures that can be used to combat this problem. While others believe that some forms of vitamin D may help in fighting some form of cancer, others have contrary opinions. For instance, the sun is believed to be beneficial for the skin because it helps in the synthesis of vitamin D. however, the sun rays are widely believed to be one of the major causes of skin cancer. This contradiction makes it difficult to come up with conclusive information about the relevance of vitamin D in managing cancer. From their study, it was revealed that Hypovitaminosis D has a worse projection in some of the cancers. On the other hand, vitamin D supplementation did not demonstrate any benefit to patients suffering from prostate cancer. They concluded that there is insufficient evidence to support the use of vitamin D for cancer patients in a clinical practice.

Assessment

In this systematic review, the researchers took an appropriate sample source to gather the relevant information. Their research is convincing because they viewed articles written by both the opponents and proponents of vitamin D in the fight against cancer.

Reflection

The study demonstrates that although vitamin D is an important nutrient to the body, there is a need to conduct further researches in order to validate its relevance in fighting cancer.

Annotation #2

Ganesh A, Apel S, Metz L, Patten S. The case for vitamin D supplementation in multiple sclerosis. Multiple Sclerosis and Related Disorders. 2013; 2(4): 281-306.

Summary

Vitamin D is known to be very important in immunomodulation. Recent studies reveal that it correlates with the development of MS (Multiple Sclerosis). There is an opinion among the medical experts tat vitamin D may influence activities of disease among the MS patients. In this systematic review paper, the researchers were interested in gathering evidences to determine the actual role of vitamin D in influencing the activities of disease in MS patients in order to make a recommendation on the therapeutic supplementation of this nutrient for MS patients. According to these researchers, there is a long path that needs to be taken in order to come up with comprehensive information about the relationship of vitamin D and disease activity among MS patients. Although they agree that this line of medication has a highly promising future, there is a common belief that a lot more needs to be done in terms of further research in order to come up with a definitive conclusion. Currently, it is still unclear how the dosage of this supplement should be given. They believe that some of the controversies that existed earlier on the use of vitamin D for MS patients have been eliminated. The medical experts will need to come up with clear information about the right dosage for this supplement in order to eliminate the current controversies.

Assessment

The randomized clinical trials that were conducted by the researchers with placebo arms are convincing. The researchers remained objective in their entire study, making their findings appear credible.

Reflection

In the study, the researchers have given their opinion about the relevance of vitamin D in the treatment of MS patients. From their study, it is clear that a further investigative research is necessary.

Annotation #3

Cayir A, Turan M, Ozkan O, Cayir Y. Vitamin D levels in children diagnosed with acute otitis media. J Pak Med Assoc. 2014; 64(11):1274-7.

Summary

Acute otitis media is one of the most common diseases that affect children, especially those who are at the infancy stage of development. The disease is always accompanied by pain in the eardrum. Sometimes purulent material, also known as pus, may ooze out of the year. These researchers were interested in investigating the relationship between acute otitis media and vitamin D. Some doctors are already prescribing vitamin D for children below six years as a measure that can help fight this disease. It was important to investigate the relevance of this form of medication to the patients so as to eliminate any doubts. These researchers conducted an experiment at Ataturk University in their Pediatric Department. They were able to establish that there is a relationship between vitamin D and the ability of the body system to fight acute otitis media. Administering a serum of vitamin D was confirmed to have a positive impact on the ability of a child to fight otitis media infection. Although these scholars did not conclude that vitamin D can be used as a vaccine to this disease, they were able to confirm that regular intake of this vitamin reduces chances of infection to a great level.

Assessment

The randomized case-controlled scientific study conducted by the researchers made use of the mathematical methods. This quantitative research used SPSS to process the raw data and come up with a conclusion. This made the findings very convincing.

Reflection

From this study, it is clear that vitamin D supplement may help minimize or even eliminate chances of a child contracting acute otitis media. This clear finding eliminates the misinformation that existed before in this area of medication.

Bibliography

Buttigliero C, Berruti A. Prognostic role of vitamin D status and efficacy of vitamin D supplementation in cancer patients: a systematic review. Oncologist. 2011; 16(9): 1215-1227.

Cayir A, Turan M, Ozkan O, Cayir Y. Vitamin D levels in children diagnosed with acute otitis media. J Pak Med Assoc. 2014; 64(11):1274-7.

Ganesh A, Apel S, Metz L, Patten S. The case for vitamin D supplementation in multiple sclerosis. Multiple Sclerosis and Related Disorders. 2013; 2(4): 281-306.

Identification of the Problem

Vitamin A deficiency has been defined in different ways by different scholars. For instance, the World Health Organizations states that vitamin A deficiency is “the situation that exists when tissue levels are depleted to a level at which health consequences occur even in the absence of xerophthalmia,” (cited by Low 1997, p. 1). Vitamin A deficiency has also been defined using several terms: Xerophthalmia – if the patient exhibited any clinical signs of vitamin A deficiency in one or both eyes (Haidar & Demissie 1999); severe hyporetinolaemia – if the level of serum retinol in the patient is less than 0.35 µmol/l; mild to moderate hyporetinolaemia – if the level of serum retinol in the patient ranged between 0.35 and 0.70 µmol/l; and low vitamin A reserve – if the modified relative dose response rate is greater than or equal to 0.06 (Kassaye et al. 2003).

Irrespective of the definition adopted for vitamin A deficiency, vitamin A plays an important role in the functioning of the body. It is especially important for optimal vision and inadequate consumption of the micronutrient often leads to night blindness or total blindness. This is because vitamin A plays a key role in phototransduction. In the eyes, the cone cells play the role of the absorption of light and colour vision when there is bright light. Lack of adequate vitamin A makes it impossible for the eyes to produce visual pigments which in turn minimize the absorption of different wavelengths of light thus leading to blindness (Gropper, Smith & Groff 2005). Although vitamin A deficiency is commonly associated with visual impairments, the deficiency also causes other health problems which include: Bitot spots – Bitot spots are defined as “areas of abnormal squamous cell proliferation and keratinization of the conjunctiva,” (Semba 2007, p. 3). VAD leads to high rates of mortality among infants and children aged below 6 years. It increases the seriousness, consequences, and risk of death as a result of measles. It is linked to high rates of disease among infants, especially in the seriousness of disease episodes, for instance, diarrheal and pneumonia. It leads to the wrinkling and premature aging of skin which appears as rough and dry, as well as general skin disorders (Shils & Shike 2006). It dries up the mucous membranes found in the mouth and the respiratory and reproductive organs. VAD also causes a variety of allergic reactions (Higdon 2003).

Vitamin A deficiency is caused by two major factors: the lack of adequate consumption of vitamin A and the inability of the body to absorb or ingest vitamin A due to high rates of morbidity caused by diseases such as malaria, measles and parasitic infections (Palmer 2004). The effects of vitamin A deficiency on the sufferers and the wider community lie in the inability and difficulty to diagnose it just by observation (Kassaye et al. 2003). In most cases therefore, vitamin A deficiency is usually diagnosed clinically by trained community health workers.

Justification for Carrying Out the Intervention Strategy

Clinical and sub-clinical vitamin A deficiency is prevalent in Ethiopia among children as well as pregnant and lactating mothers in whom tremendously low levels of serum retinol are found. In general, the consumption of vitamin A is usually insufficient due to the seasonality of sources of food, the early desertion of exclusive breast feeding, high rates of morbidity, and the general practice of not feeding children with foods that are rich in vitamin A. Since the early 1990s, the key intervention strategy for dealing with VAD not only in Ethiopia but also other Sub-Saharan countries has been to hand out huge doses of vitamin A capsules to children who have been diagnosed as having vitamin A deficiency through clinical examinations. Whereas the supplementation method through vitamin A capsules to children and at-risk mothers helps to address VAD to some extent (Berger et al. 2007), the method is often subject to failure due to a number of reasons.

First, the Sub-Saharan countries are generally poor countries and often cannot afford to provide vitamin A supplements to all VAD patients. In most cases therefore, supplementation is achieved through donors who send the capsules to the affected populations. The problem of reliance on donors lies in the lack of sustainability. If the donors decide to halt their assistance, the beneficiary countries in question will not be in a position to continue with the intervention programs. Another problem of supplementation is its inability to reach all the members of the target population particularly due to corruption of government officials in charge of the distribution. It is therefore common to find that some not-so-deserving children benefitting from the supplementation program at the expense of the more deserving children. Another challenge facing supplementation programs is their costly nature which prevents them from being a long-term solution (Black, Morris & Bryce 2003).

Vitamin A deficiency usually starts to peak from the age of 2 to 4 years. At this age, however, majority of mothers tend to have stopped taking their children for monthly clinical check ups because of the completion of infant immunization at the age of 9 months. Given all these factors, the most effective intervention strategy for combating vitamin A deficiency would be a preventative one rather than a curative one. In the selection of any intervention strategy, technical feasibility, cost-effectiveness and sustainability are the three key issues that need to be addressed (Ekvall & Ekvall 2005). The intervention strategy proposed in this paper is a foods-based strategy which is achieved through agricultural production of foods rich in vitamins A, in this case orange- and yellow-fleshed sweet potatoes (Pitchford 2003). The justifications for the production of sweet potatoes as the VAD intervention strategy include: Suitability – vitamin A deficiency is the most suitable to agriculturally-based interventions among the major micronutrient deficiencies; cost – yellow- and orange-fleshed sweet potatoes are the cheapest source of dietary vitamin A that households can produce throughout the year; source of calories – among all the available major plant sources of vitamin A, sweet potato is the best source of calories (Low, Walker & Hijmans 2001); and recommended daily intake – the regular consumption of yellow- and orange-fleshed sweet potatoes can ensure the achievement of the recommended daily allowances of vitamin A (Sommer & Davidson 2002).

Aims and Objectives of the Intervention Strategy

The main goal of the proposed intervention strategy is to ensure that Ethiopian school going children have adequate intake of vitamin A in their diets. The major objectives of the intervention strategy include:

• To initiate and assess the varieties of B-carotene-rich sweet potatoes among Ethiopian communities which are adversely affected by vitamin A deficiency
• To educate communities on the role that Vitamin A plays in the diet for both children and adults through working directly with women’s groups, mobilizing public health workers, and using different channels of the mass media
• To work with women’s groups in the production and marketing of processed sweet potato products as income-generating activities
• To enhance the capacity for the women’s groups to supervise and assess their own progress regarding the suitability of different varieties of sweet potatoes as well as the feasibility of the processed products

Potential Benefits of the Proposed Intervention Strategy

The proposed intervention strategy, if successful, is likely to result in: Enhanced own production and consumption of fresh sweet potatoes as well as processed products made from sweet potatoes such as flour; an increased intake of foods that are good sources of vitamin A among children and the entire household; an extra source of income for the households which in turn translate into higher standards of living; the consumption of additional sources of vitamin A and health services through the income generated from the program; the women taking part in the program will gain more knowledge and skills in matters concerning diets and general health as well as in the production, marketing and selling of sweet potatoes; and an improved teamwork and communal spirit among the members of the community through their active participation in the programs particularly

Planned Coverage of the Program

The sweet potato-based intervention strategy will be undertaken in the Eastern zone of Tigray administrative region of Ethiopia. In this region, the prevalence of vitamin A deficiency is extremely high among children. The target population for this program will however be children aged between 5 and 9 years. This is a population of school going children suffering from VAD. The choice for this target population lies in the fact that they need good vision and generally good health to be able to undertake their studies successfully. According to Kassaye et al. (2001), the Eastern zone of Tigray administrative region has 4423 children suffering from xerophthalmia, 6406 children suffering from serum retinol levels below 0.35 µmol/l, 38,968 children suffering from serum retinol levels ranging between 0.35 and 0.70 µmol/l, and 31,266 children suffering from vitamin A reserve of greater than or equal to 0.06. All these are children aged below 9 years. The program will also target mothers with school going children. This is because it is the mothers who feed their children and therefore their involvement in the program will ensure that they benefit from the program by learning the best and healthy foods to feed their children.

Ensuring the Acceptance of the Intervention Strategy by the Community

Before the implementation of the program, the program officers will convene with important figures of the communities including: the community elders, community health workers, institutions such as non-profit-making groups, schools, and churches. The involvement and support of these important figures will determine the success or failure of the intervention strategy (Sanders 1999). Once the program officers have been given the go-ahead by the community, the program officers will then meet with all women in each community who have young and school going children. This meeting will form the foundation upon which the program officers will discuss with the mothers about vitamin A deficiency, its effects on children and the entire society and the methods through which the VAD can be eliminated or prevented.

The meeting will also provide the program officers with the opportunity to justify the choice of the particular intervention strategy chosen. This will be done by educating the women on the different intervention strategies that can be used to address VAD, including their pros and cons. Without such a detailed explanation, the community may not understand why the sweet potato-based strategy has been selected instead of other seemingly easier strategies such as supplementation. The program officers will therefore have to convince the communities involved that the proposed strategy is more beneficial than others (Tontisirin & Winichagoon 1999).

Methods Used in the Intervention Strategy

The vitamin A deficiency intervention strategy will be carried out through two main methods: production and marketing of sweet potatoes, and nutritional education.

Production and marketing of sweet potatoes

The chief objective of the community intervention strategy is the extension of B-carotene-rich sweet potato varieties throughout the communities in the Eastern zone of Tigray administrative region. The program will however be facilitated through the creation of 10- or 20-member women groups. The choice of the women groups as the socialization agents is due to the fact that women still remain the key home keepers in most regions of Sub-Saharan Africa. In addition, women are more involved than men in farming and other agricultural activities. It is therefore important for the program to actively involve women. Once the women groups have been formed, an appropriate number of extension and health officers will undergo an extensive training on the role of vitamin A in the general health as well as on the methods of improving the cultivation of different varieties of sweet potatoes. The trained extension and health officers will then train the women in their groups about the same.

Once the training is done, the women will go ahead with the cultivation of different sweet potato varieties specifically the yellow- and orange-fleshed varieties in their plots. The women’s groups will act as the agents of dissemination and distribution of knowledge to the other members of the communities. The sweet potato varieties which performed well in this initial intervention phase will then be rapidly multiplied in selected primary sites throughout the communities. These varieties will then be distributed to each affected household for home gardening so that each household cultivates its own sweet potatoes both for home consumption and sale if desired. During the distribution of the sweet potato varieties to the households, a lecture will be given about the role played by vitamin A in our diets and how sweet potatoes are a good source of vitamin A (Low 1997).

The intervention strategy will also involve extensive marketing and promotion of yellow- and orange-fleshed sweet potato varieties especially among the urban communities where farming is limited due to a dense population and subsequent lack of adequate farming land. Market surveys will be conducted in these urban centres to determine the acceptance of processed products made from sweet potatoes such as flour. The promotion of sweet potatoes will not only be done to households but also to local market vendors who will be encouraged to sell sweet potatoes in lieu of other ingredients. Taking into consideration any technical or marketing challenges involved in the substitution of sweet potatoes for other ingredients, the program officers will work together with the local vendors and processors to address the challenges (World Bank 2001).

Market demonstrations will be created to reach more households in the urban centres. In addition, the mass media particularly radio programs will also be used to disseminate knowledge and to create awareness among the urban households concerning vitamin A deficiency and its adverse consequences as well as the importance of diets in addressing this deficiency (Low, Walker & Hijmans 2001).

Nutritional education

Due to the limited availability of modern channels of communication in the rural communities, the program officers will place emphasis on developing flip charts and the use of practical demonstrations to disseminate nutritional knowledge and enhance health practices among the women’s groups and the entire community (Tontisirin & Gillespie 1999). The Agricultural Information Services will help in this area by creating and testing these educational materials. The nutrition education messages will concentrate around a number of key main points including: The chief benefits of vitamin A – vitamin A is a micronutrient that is necessary in the fight against grave illnesses, and it also helps in the optimal functioning of the eyesight; how to differentiate between the major, minor, and insignificant sources of vitamin A; the role of fat in the absorption of vitamin A; the role of colostrum in promoting the health of infants; and the need for frequent feeding of children. These educative messages will put emphasis on the association between inadequate intake of vitamin A and illnesses such as measles.

Time Frame

The time frame for the successful implementation of the sweet potato-based intervention strategy will be approximately fifteen months. The activities that will be carried out throughout the designated time frame are as follows:

• 1^st month – a qualitative assessment of the region will be done by the program officers. The officers will convene with the key figures and institutions of the community to propose and convince them of the feasibility of the program. In the same month, the program officers will also meet with the women’s groups to discuss about vitamin A deficiency and the proposed intervention strategy. Market surveys will also be carried out during this month to determine consumer behaviour regarding the new varieties of sweet potatoes. The familiarity of community health workers and extension officers about vitamin A will also be determined.
• 2^nd to 3^rd month – the planting of new sweet potato varieties on women’s groups’ plots will be done. The successful varieties will then be multiplied rapidly on selected primary sites. Distribution of the successful varieties from the plots of the women’s groups and the primary sites to other households will also be done in this month.
• 4^th month – Extension agents from non-governmental organizations will be posted full-time throughout the communities.
• 4^th to 6^th month – Home visits will be done to determine the child feeding practices of households in the communities
• 7^th month – Harvest of the planted sweet potatoes will be done. Taste evaluation of the initial round of on-farm yields will be done on all the new varieties of sweet potatoes.
• 5^th to 10^th month – during this time period, the nutrition education materials will be developed, and pre-tested at the community level. Marketing and promotion of the sweet potatoes will also be carried out to the urban centres.
• 11^th to 14^th month – A laboratory analysis for B-carotene content will be conducted on the new varieties of sweet potatoes to determine if they can provide the daily recommended amount of vitamin A.
• 15^th month – Finalization of the intervention strategy will be done in which the program officers will determine the success or failure of the intervention strategy in addressing vitamin A deficiency in the selected region. If successful, the strategy will be adopted by the community as a long-term solution to the problem of vitamin A deficiency.

Cost Effectiveness

The cost effectiveness of this program will be measured using the disability adjusted life year (DALY) which is a measurement that is equal to a year of healthy life that is lost as a result of a health condition. The calculation of DALY is done by “combining the years of life lost from a disease and the years of life spent with disability from the disease,” (Semba & Bloem 2008, p. 867). The cost effectiveness of this program is approximated to be $25 per every DALY saved. The program is therefore cost-effective because it will take the community only $25 to save one life that would otherwise have been lost or disabled due to the complications brought about by vitamin A deficiency (Duggan, Watkins & Walker 2008).

Agencies Involved

A number of agencies will be involved in this program, including: Non-governmental organizations – NGOs dealing with health and nutrition and agriculture will take part in the program to train local health and extension officers and to oversee the overall implementation of the program; Agricultural Information Services – this agency will assist in the development and testing of educational materials to be disseminated throughout the communities; media agencies – these agencies will assist in the dissemination of information to the communities particularly to the urban centres; and market research organizations – these organizations will conduct market surveys throughout the communities and urban centres to determine consumer behaviour regarding the new varieties of sweet potatoes.

Outcomes Assessment

The impact of the sweet potato-based intervention strategy at the community level will be evaluated through several ways: Quarterly examinations of the quantities and prices of the new varieties of sweet potatoes on the market; the rate of dissemination of planting materials to other households in the wider community; close supervision of the decline in seasonal fluctuations in the supply of sweet potatoes as well as the accessibility of sufficient amounts of planting material so as to ensure the sustainability of a year-round availability of B-carotene-rich roots; the existence of new varieties of sweet potatoes throughout the communities; and finally, child feeding patterns in the households will be assessed to ensure that children receive the recommended daily intake of vitamin A-rich foods.

Reference List

Berger, S., De Pee, S., Bloem, M. et al. 2007, ‘High malnutrition and morbidity among children who are missed by periodic vitamin A capsule distribution for child survival in rural Indonesia’, Journal of Nutrition, vol. 137, pp. 1328-33.

Black, R., Morris, S. & Bryce, J. 2003, ‘Where and why are 10 million children dying every year?’, Lancet, vol. 361, pp. 2226-34.

Duggan, C., Watkins, J. & Walker, A. 2008, Nutrition in paediatrics: Basic Science, Clinical Applications, PMPH-USA, Lewiston, NY.

Ekvall, S. & Ekvall, V. 2005, Paediatric nutrition in chronic diseases and developmental disorders, Oxford University Press, Oxford.

Gropper, S., Smith, J. & Groff, J. 2005, Advanced nutrition and human metabolism, Cengage Learning, Belmont, CA.

Haidar, J. & Demissie, T. 1999, ‘Malnutrition and xerophthalmia in rural communities of Ethiopia’, East African Medical Journal, vol. 76, pp. 590-3.

Higdon, J. 2003, An evidence-based approach to vitamins and minerals: health implications and intake recommendations, Thieme, New York.

Kassaye, T., Receveur, O., Johns, T. et al. 2001, ‘Prevalence of vitamin A deficiency in children aged 6-9 years in Wukro, northern Ethiopia’, Bull World Health Organization, vol. 79, pp. 415-22.

Low, J. 1997, Combating vitamin A deficiency through the use of sweet potato: results from phase 1 of an action research project in South Nyanza, Kenya, International Potato Centre, Peru.

Low, J., Walker, T. & Hijmans, R. 2001, The potential impact of orange-fleshed sweet potatoes on vitamin A intake in Sub-Saharan Africa, The VITAA Project, Nairobi.

Palmer, M. 2004, Doctor Melissa Palmer’s guide to hepatitis and liver disease, Avery, New York.

Pitchford, P. 2003, Healing with whole foods: Asian traditions and modern nutrition, North Atlantic Books, Berkeley, CA.

Sanders, D. 1999, ‘Success factors in community-based nutrition programmes’, Food and Nutrition Bulletin, vol. 20, suppl. 3, pp. 307-314.

Semba, R, & Bloem, M.W. 2008, Nutrition and health in developing countries, Humana Press, Totowa, NJ.

Semba, R. 2007, Handbook of nutrition and ophthalmology, Humana Press, Totowa, NJ.

Shils, M., & Shike, M. 2006, Modern nutrition in health and disease, Lippincott Williams & Wilkins, New York.

Sommer, A. & Davidson, F. 2002, ‘Assessment and control of vitamin A deficiency: the Annecy Accords’, Journal of Nutrition, vol. 132, no. 9, pp. 2845S-50S.

Tontisirin, K. & Gillespie, S. 1999, ‘Linking community based programmes and service delivery for improving maternal and child nutrition’, Asian Development Review, vol. 17, no. 1-2, pp. 33-65.

Tontisirin, K. & Winichagoon, P. 1999, ‘Community-based programmes: Success factors for public nutrition derived from the experience of Thailand’, Food and Nutrition Bulletin, vol. 20, no. 3, pp. 315-322.

World Bank. 2001, Decentralization and governance: Does decentralization improve service delivery? PREM Notes Number 55, World Bank, Washington, D.C.