Instruct: Given a question, retrieve relevant documents that answer the question.
Query: Vitamin D Pills vs. Tanning Beds
Deficiency of vitamin D is usually caused by dietary deficiency and/or lack of exposure to sunlight in dark skinned individuals living at northern latitudes. Simple vitamin D deficiency is commonly treated by prescribing a vitamin D containing calcium supplement. This report presents a patient who rejected this approach and instead, after researching alternative treatment options independently, opted to self-treat by consuming UVB-irradiated mushrooms. The beneficial effect of this on the patient's plasma biochemical markers is shown. Further research into the beneficial effect of consuming UVB-irradiated mushrooms is required.
Context: Two reports suggested that vitamin D2 is less effective than vitamin D3 in maintaining vitamin D status. Objective: Our objective was to determine whether vitamin D2 was less effective than vitamin D3 in maintaining serum 25-hydroxyvitamin D levels or increased the catabolism of 25-hydroxyvitamin D3. Subjects and Design: This was a randomized, placebo-controlled, double-blinded study of healthy adults ages 18–84 yr who received placebo, 1000 IU vitamin D3, 1000 IU vitamin D2, or 500 IU vitamin D2 plus 500 IU vitamin D3 daily for 11 wk at the end of the winter. Results: Sixty percent of the healthy adults were vitamin D deficient at the start of the study. The circulating levels of 25-hydroxyvitamin D (mean ± sd) increased to the same extent in the groups that received 1000 IU daily as vitamin D2 (baseline 16.9 ± 10.5 ng/ml; 11 wk 26.8 ± 9.6 ng/ml), vitamin D3 (baseline 19.6 ± 11.1 ng/ml; 11 wk 28.9 ± 11.0 ng/ml), or a combination of 500 IU vitamin D2 and 500 IU vitamin D3 (baseline 20.2 ± 10.4 ng/ml; 11 wk 28.4 ± 7.7 ng/ml). The 25-hydroxyvitamin D3 levels did not change in the group that received 1000 IU vitamin D2 daily. The 1000 IU dose of vitamin D2 or vitamin D3 did not raise 25-hydroxyvitamin D levels in vitamin D-deficient subjects above 30 ng/ml. Conclusion: A 1000 IU dose of vitamin D2 daily was as effective as 1000 IU vitamin D3 in maintaining serum 25-hydroxyvitamin D levels and did not negatively influence serum 25-hydroxyvitamin D3 levels. Therefore, vitamin D2 is equally as effective as vitamin D3 in maintaining 25-hydroxyvitamin D status.
BACKGROUND/OBJECTIVES: Mushrooms contain very little or any vitamin D(2) but are abundant in ergosterol, which can be converted into vitamin D(2) by ultraviolet (UV) irradiation. Our objective was to investigate the bioavailability of vitamin D(2) from vitamin D(2)-enhanced mushrooms by UV-B in humans, and comparing it with a vitamin D(2) supplement. SUBJECTS/METHODS: Fresh mushrooms were irradiated with an UV-B dose of 1.5 J/cm(2), increasing vitamin D(2) content from <1 to 491 μg/100 g and made to an experimental soup. In this 5-week, single-blinded, randomized, placebo-controlled trial, 26 young subjects with serum 25-hydroxyvitamin D (25OHD) ≤ 50 nmol/l were randomly assigned into three groups ((a) mushroom, (b) supplement and (c) placebo). They received during winter (a) 28,000 IU (700 μg) vitamin D(2) via the experimental soup, or (b) 28,000 IU vitamin D(2) via a supplement or (c) placebo, respectively. RESULTS: After 2 weeks, serum 25OHD was significantly higher in the mushroom than in the placebo group (P=0.001). The serum 25OHD concentrations in the mushroom and supplement groups rose significantly and similarly over the study period by 3.9 nmol/l (95% confidence interval (95% CI): 2.9, 4.8) and by 4.7 nmol/l per week (95% CI: 3.8, 5.7), respectively. CONCLUSIONS: We are the first to demonstrate in humans that the bioavailability of vitamin D(2) from vitamin D(2)-enhanced button mushrooms via UV-B irradiation was effective in improving vitamin D status and not different to a vitamin D(2) supplement. This trial was registered at http://germanctr.de as DRKS00000195.
Vitamin D was used to treat tuberculosis in the pre-antibiotic era. New insights into the immunomodulatory properties of 1alpha,25-dihydroxy-vitamin D have rekindled interest in vitamin D as an adjunct to antituberculous therapy. We describe the historical use of vitamin D in tuberculosis treatment; discuss the mechanisms by which it may modulate host response to infection with Mycobacterium tuberculosis; and review three clinical trials and ten case series in which vitamin D has been used in the treatment of pulmonary tuberculosis.
Context: Hypovitaminosis D appears to be on the rise in young children, with implications for skeletal and overall health. Objective: The objective of the study was to compare the safety and efficacy of vitamin D2 daily, vitamin D2 weekly, and vitamin D3 daily, combined with supplemental calcium, in raising serum 25-hydroxyvitamin D [25(OH)D] and lowering PTH concentrations. Design: This was a 6-wk randomized controlled trial. Setting: The study was conducted at an urban pediatric clinic in Boston. Subjects: Forty otherwise healthy infants and toddlers with hypovitaminosis D [25(OH)D < 20 ng/ml] participated in the study. Interventions: Participants were assigned to one of three regimens: 2,000 IU oral vitamin D2 daily, 50,000 IU vitamin D2 weekly, or 2,000 IU vitamin D3 daily. Each was also prescribed elemental calcium (50 mg/kg·d). Infants received treatment for 6 wk. Main Outcome Measures: Before and after treatment, serum measurements of 25(OH)D, PTH, calcium, and alkaline phosphatase were taken. Results: All treatments approximately tripled the 25(OH)D concentration. Preplanned comparisons were nonsignificant: daily vitamin D2 vs. weekly vitamin D2 (12% difference in effect, P = 0.66) and daily D2 vs. daily D3 (7%, P = 0.82). The mean serum calcium change was small and similar in the three groups. There was no significant difference in PTH suppression. Conclusions: Short-term vitamin D2 2,000 IU daily, vitamin D2 50,000 IU weekly, or vitamin D3 2,000 IU daily yield equivalent outcomes in the treatment of hypovitaminosis D among young children. Therefore, pediatric providers can individualize the treatment regimen for a given patient to ensure compliance, given that no difference in efficacy or safety was noted among these three common treatment regimens.
BACKGROUND: The available evidence on vitamin D and mortality is inconclusive. OBJECTIVES: To assess the beneficial and harmful effects of vitamin D for prevention of mortality in adults. SEARCH STRATEGY: We searched The Cochrane Library, MEDLINE, EMBASE, LILACS, the Science Citation Index Expanded, and Conference Proceedings Citation Index-Science (to January 2011). We scanned bibliographies of relevant publications and asked experts and pharmaceutical companies for additional trials. SELECTION CRITERIA: We included randomised trials that compared vitamin D at any dose, duration, and route of administration versus placebo or no intervention. Vitamin D could have been administered as supplemental vitamin D (vitamin D(3) (cholecalciferol) or vitamin D(2) (ergocalciferol)) or an active form of vitamin D (1α-hydroxyvitamin D (alfacalcidol) or 1,25-dihydroxyvitamin D (calcitriol)). DATA COLLECTION AND ANALYSIS: Six authors extracted data independently. Random-effects and fixed-effect model meta-analyses were conducted. For dichotomous outcomes, we calculated the risk ratios (RR). To account for trials with zero events, meta-analyses of dichotomous data were repeated using risk differences (RD) and empirical continuity corrections. Risk of bias was considered in order to minimise risk of systematic errors. Trial sequential analyses were conducted to minimise the risk of random errors. MAIN RESULTS: Fifty randomised trials with 94,148 participants provided data for the mortality analyses. Most trials included elderly women (older than 70 years). Vitamin D was administered for a median of two years. More than one half of the trials had a low risk of bias. Overall, vitamin D decreased mortality (RR 0.97, 95% confidence interval (CI) 0.94 to 1.00, I(2) = 0%). When the different forms of vitamin D were assessed separately, only vitamin D(3) decreased mortality significantly (RR 0.94, 95% CI 0.91 to 0.98, I(2) = 0%; 74,789 participants, 32 trials) whereas vitamin D(2), alfacalcidol, or calcitriol did not. Trial sequential analysis supported our finding regarding vitamin D(3), corresponding to 161 individuals treated to prevent one additional death. Vitamin D(3) combined with calcium increased the risk of nephrolithiasis (RR 1.17, 95% CI 1.02 to 1.34, I(2) = 0%). Alfacalcidol and calcitriol increased the risk of hypercalcaemia (RR 3.18, 95% CI 1.17 to 8.68, I(2) = 17%). Data on health-related quality of life and health economics were inconclusive. AUTHORS' CONCLUSIONS: Vitamin D in the form of vitamin D(3) seems to decrease mortality in predominantly elderly women who are mainly in institutions and dependent care. Vitamin D(2), alfacalcidol, and calcitriol had no statistically significant effect on mortality. Vitamin D(3) combined with calcium significantly increased nephrolithiasis. Both alfacalcidol and calcitriol significantly increased hypercalcaemia.
Cutaneous synthesis of vitamin D by exposure to UVB is the principal source of vitamin D in the human body. Our current clothing habits and reduced time spent outdoors put us at risk of many insufficiency-related diseases that are associated with calcaemic and non-calcaemic functions of vitamin D. Populations with traditional lifestyles having lifelong, year-round exposure to tropical sunlight might provide us with information on optimal vitamin D status from an evolutionary perspective. We measured the sum of serum 25-hydroxyvitamin D₂ and D₃ (25(OH)D) concentrations of thirty-five pastoral Maasai (34 (SD 10) years, 43 % male) and twenty-five Hadzabe hunter-gatherers (35 (SD 12) years, 84 % male) living in Tanzania. They have skin type VI, have a moderate degree of clothing, spend the major part of the day outdoors, but avoid direct exposure to sunlight when possible. Their 25(OH)D concentrations were measured by liquid chromatography-MS/MS. The mean serum 25(OH)D concentrations of Maasai and Hadzabe were 119 (range 58-167) and 109 (range 71-171) nmol/l, respectively. These concentrations were not related to age, sex or BMI. People with traditional lifestyles, living in the cradle of mankind, have a mean circulating 25(OH)D concentration of 115 nmol/l. Whether this concentration is optimal under the conditions of the current Western lifestyle is uncertain, and should as a possible target be investigated with concomitant appreciation of other important factors in Ca homeostasis that we have changed since the agricultural revolution.
OBJECTIVE: The objective was to provide guidelines to clinicians for the evaluation, treatment, and prevention of vitamin D deficiency with an emphasis on the care of patients who are at risk for deficiency. PARTICIPANTS: The Task Force was composed of a Chair, six additional experts, and a methodologist. The Task Force received no corporate funding or remuneration. CONSENSUS PROCESS: Consensus was guided by systematic reviews of evidence and discussions during several conference calls and e-mail communications. The draft prepared by the Task Force was reviewed successively by The Endocrine Society's Clinical Guidelines Subcommittee, Clinical Affairs Core Committee, and cosponsoring associations, and it was posted on The Endocrine Society web site for member review. At each stage of review, the Task Force received written comments and incorporated needed changes. CONCLUSIONS: Considering that vitamin D deficiency is very common in all age groups and that few foods contain vitamin D, the Task Force recommended supplementation at suggested daily intake and tolerable upper limit levels, depending on age and clinical circumstances. The Task Force also suggested the measurement of serum 25-hydroxyvitamin D level by a reliable assay as the initial diagnostic test in patients at risk for deficiency. Treatment with either vitamin D(2) or vitamin D(3) was recommended for deficient patients. At the present time, there is not sufficient evidence to recommend screening individuals who are not at risk for deficiency or to prescribe vitamin D to attain the noncalcemic benefit for cardiovascular protection.
Many patients treated for vitamin D deficiency fail to achieve an adequate serum level of 25-hydroxyvitamin D [25(OH)D] despite high doses of ergo- or cholecalciferol. The objective of this study was to determine whether administration of vitamin D supplement with the largest meal of the day would improve absorption and increase serum levels of 25(OH)D. This was a prospective cohort study in an ambulatory tertiary-care referral center. Patients seen at the Cleveland Clinic Foundation Bone Clinic for the treatment of vitamin D deficiency who were not responding to treatment make up the study group. Subjects were instructed to take their usual vitamin D supplement with the largest meal of the day. The main outcome measure was the serum 259(OH)D level after 2 to 3 months. Seventeen patients were analyzed. The mean age (+/-SD) and sex (F/M) ratio were 64.5 +/- 11.0 years and 13 females and 4 males, respectively. The dose of 25(OH)D ranged from 1000 to 50,000 IU daily. The mean baseline serum 25(OH)D level (+/-SD) was 30.5 +/- 4.7 ng/mL (range 21.6 to 38.8 ng/mL). The mean serum 25(OH)D level after diet modification (+/-SD) was 47.2 +/- 10.9 ng/mL (range 34.7 to 74.0 ng/mL, p < .01). Overall, the average serum 25(OH)D level increased by 56.7% +/- 36.7%. A subgroup analysis based on the weekly dose of vitamin D was performed, and a similar trend was observed.Thus it is concluded that taking vitamin D with the largest meal improves absorption and results in about a 50% increase in serum levels of 25(OH)D levels achieved. Similar increases were observed in a wide range of vitamin D doses taken for a variety of medical conditions. Copyright 2010 American Society for Bone and Mineral Research.
Observations of increasing allergy prevalence with decreasing distance from the Equator and positive associations with ambient ultraviolet radiation have contributed to a growing interest in the possible role of vitamin D in the etiology of allergy. The aims of this study were to describe any latitudinal variation in the prevalence of childhood allergy in Australia and to evaluate, in parallel, the individual associations between ultraviolet radiation (UVR)- and vitamin D-related measures and hayfever asthma and both conditions. Participants were population-based controls who took part in a multicenter case-control study, aged 18-61 yr and resident in one of four study regions ranging in latitude from 27°S to 43°S. Data were derived from a self-administered questionnaire, interview and examination by a research officer and biologic sampling. Latitude and longitude coordinates were geocoded from participants' residential locations and climatic data were linked to postcodes of current residence. Stored serum was analyzed for 25-hydroxyvitamin D concentrations and silicone rubber casts of the skin were used as an objective measure of cumulative actinic damage. There was an inverse latitude gradient for asthma (a 9% decrease per increasing degree of latitude); however, this pattern did not persist after adjusting for average daily temperature. There was no association between any of the UVR- or vitamin D-related measures and childhood asthma, but greater time in the sun in winter between the ages 6-15 yr was associated with an increase in the odds of having hayfever [adjusted odds ratios (OR) 1.29; 95% CI 1.01-1.63]. Oral supplementation with cod liver oil in childhood increased the odds of a history of having both asthma and hayfever (2.87; 1.00-8.32). Further investigation of the possible role of early vitamin D supplementation in the development of allergy is warranted. Our results also suggest that solar exposure during childhood may be important in allergic sensitization. Plausible explanations, including biologic mechanisms, exist for both observations. © 2010 John Wiley & Sons A/S.
BACKGROUND: Current unitage for the calciferols suggests that equimolar quantities of vitamins D(2) (D2) and D(3) (D3) are biologically equivalent. Published studies yield mixed results. OBJECTIVE: The aim of the study was to compare the potencies of D2 and D3. DESIGN: The trial used a single-blind, randomized design in 33 healthy adults. Calciferols were dosed at 50,000 IU/wk for 12 wk. Principal outcome variables were area under the curve for incremental total 25-hydroxyvitamin D [25(OH)D] and change in calciferol content of sc fat. RESULTS: Incremental mean (sd) 25(OH)D area under the curve at 12 wk was 1366 ng · d/ml (516) for the D2-treated group and 2136 (606) for the D3 (P < 0.001). Mean (sd) steady-state 25(OH)D increments showed similar differences: 24 ng/ml for D2 (10.3) and 45 ng/ml (16.2) for D3 (P <0.001). Subcutaneous fat content of D2 rose by 50 μg/kg in the D2-treated group, and D3 content rose by 104 μg/kg in the D3-treated group. Total calciferol in fat rose by only 33 ng/kg in the D2-treated, whereas it rose by 104 μg/kg in the D3-treated group. Extrapolating to total body fat D3, storage amounted to just 17% of the administered dose. CONCLUSION: D3 is approximately 87% more potent in raising and maintaining serum 25(OH)D concentrations and produces 2- to 3-fold greater storage of vitamin D than does equimolar D2. For neither was there evidence of sequestration in fat, as had been postulated for doses in this range. Given its greater potency and lower cost, D3 should be the preferred treatment option when correcting vitamin D deficiency.
The North American Institute of Medicine (IOM) recently published their report on dietary reference intakes (DRI) for Ca and vitamin D. The DRI committee's deliberations underpinning this most comprehensive report on vitamin D nutrition to date benefited hugely from a much expanded knowledge base in vitamin D over the last decade or more. However, since their release, the vitamin D DRI have been the subject of intense controversy, which is largely due to the persistence of fundamental knowledge gaps in vitamin D. These can be identified at the levels of exposure, metabolism, storage, status, dose-response, function and beneficial or adverse health effects, as well as safe and effective application of intake recommendations at the population level through sustainable food-based approaches. The present review provides a brief overview of the approach used by the IOM committee to revise the DRI for vitamin D and to collate from a number of authoritative sources key knowledge gaps in vitamin D nutrition from the public health perspective. A number of research topics are outlined and data requirements within these are identified and mapped to the risk assessment framework used by the DRI committee. While not intended as an exhaustive list, it provides a basis for organising and prioritising research efforts in the area of vitamin D, which may offer a perspective on the major areas in need of attention. It is intended to be of use to researchers, national policy makers, the public health community, industry groups and other relevant stakeholders including funding institutions.
Background: Currently, there is a lack of clarity in the literature as to whether there is a definitive difference between the effects of vitamins D2 and D3 in the raising of serum 25-hydroxyvitamin D [25(OH)D]. Objective: The objective of this article was to report a systematic review and meta-analysis of randomized controlled trials (RCTs) that have directly compared the effects of vitamin D2 and vitamin D3 on serum 25(OH)D concentrations in humans. Design: The ISI Web of Knowledge (January 1966 to July 2011) database was searched electronically for all relevant studies in adults that directly compared vitamin D3 with vitamin D2. The Cochrane Clinical Trials Registry, International Standard Randomized Controlled Trials Number register, and clinicaltrials.gov were also searched for any unpublished trials. Results: A meta-analysis of RCTs indicated that supplementation with vitamin D3 had a significant and positive effect in the raising of serum 25(OH)D concentrations compared with the effect of vitamin D2 (P = 0.001). When the frequency of dosage administration was compared, there was a significant response for vitamin D3 when given as a bolus dose (P = 0.0002) compared with administration of vitamin D2, but the effect was lost with daily supplementation. Conclusions: This meta-analysis indicates that vitamin D3 is more efficacious at raising serum 25(OH)D concentrations than is vitamin D2, and thus vitamin D3 could potentially become the preferred choice for supplementation. However, additional research is required to examine the metabolic pathways involved in oral and intramuscular administration of vitamin D and the effects across age, sex, and ethnicity, which this review was unable to verify.
The use of nutritional supplements in the general population and in cancer patients has become very popular. These supplements are not perceived as medications and are presumed to be safe by cancer patients, who may however be at risk for hypercalcemia. We note that many of our patients who have developed symptomatic hypercalcemia were taking vitamin D, calcium, or shark cartilage supplements. We report eight cases of hypercalcemia in cancer patients seen at the Cleveland Clinic Foundation in whom these nutritional supplements may have contributed to the prevalence or severity of hypercalcemia.
Mounting evidence suggests that vitamin D deficiency could be linked to several chronic diseases, including cardiovascular disease and cancer. The purpose of this study was to examine the prevalence of vitamin D deficiency and its correlates to test the hypothesis that vitamin D deficiency was common in the US population, especially in certain minority groups. The National Health and Nutrition Examination Survey 2005 to 2006 data were analyzed for vitamin D levels in adult participants (N = 4495). Vitamin D deficiency was defined as a serum 25-hydroxyvitamin D concentrations ≤20 ng/mL (50 nmol/L). The overall prevalence rate of vitamin D deficiency was 41.6%, with the highest rate seen in blacks (82.1%), followed by Hispanics (69.2%). Vitamin D deficiency was significantly more common among those who had no college education, were obese, with a poor health status, hypertension, low high-density lipoprotein cholesterol level, or not consuming milk daily (all P < .001). Multivariate analyses showed that being from a non-white race, not college educated, obese, having low high-density lipoprotein cholesterol, poor health, and no daily milk consumption were all significantly, independently associated with vitamin D deficiency (all P < .05). In summary, vitamin D deficiency was common in the US population, especially among blacks and Hispanics. Given that vitamin D deficiency is linked to some of the important risk factors of leading causes of death in the United States, it is important that health professionals are aware of this connection and offer dietary and other intervention strategies to correct vitamin D deficiency, especially in minority groups. Copyright © 2011 Elsevier Inc. All rights reserved.
Tuberculosis (TB) is a major cause of mortality, responsible for 1·68 million deaths worldwide in 2009. The global prevalence of latent Mycobacterium tuberculosis infection is estimated to be 32%, and this carries a 5-20% lifetime risk of reactivation disease. The emergence of drug-resistant organisms necessitates the development of new agents to enhance the response to antimicrobial therapy for active TB. Vitamin D was used to treat TB in the pre-antibiotic era, and its active metabolite, 1,25-dihydoxyvitamin D, has long been known to enhance the immune response to mycobacteria in vitro. Vitamin D deficiency is common in patients with active TB, and several clinical trials have evaluated the role of adjunctive vitamin D supplementation in its treatment. Results of these studies are conflicting, reflecting variation between studies in baseline vitamin D status of participants, dosing regimens and outcome measures. Vitamin D deficiency is also recognised to be highly prevalent among people with latent M. tuberculosis infection in both high- and low-burden settings, and there is a wealth of observational epidemiological evidence linking vitamin D deficiency with increased risk of reactivation disease. Randomised controlled trials of vitamin D supplementation for the prevention of active TB have yet to be performed, however. The conduct of such trials is a research priority, given the safety and low cost of vitamin D supplementation, and the potentially huge public health consequences of positive results.
BACKGROUND: Common warts (verruca vulgaris) are benign epithelial proliferations associated with human papillomavirus (HPV) infection. Salicylic acid and cryotherapy are the most frequent treatments for common warts, but can be painful and cause scarring, and have high failure and recrudescence rates. Topical vitamin A has been shown to be a successful treatment of common warts in prior informal studies. CASE: The subject is a healthy, physically-active 30 old female with a 9 year history of common warts on the back of the right hand. The warts resisted treatment with salicylic acid, apple cider vinegar and an over-the-counter blend of essential oils marketed for the treatment of warts. Daily topical application of natural vitamin A derived from fish liver oil (25,000 IU) led to replacement of all the warts with normal skin. Most of the smaller warts had been replaced by 70 days. A large wart on the middle knuckle required 6 months of vitamin A treatment to resolve completely. CONCLUSION: Retinoids should be further investigated in controlled studies to determine their effectiveness in treating common warts and the broad range of other benign and cancerous lesions induced by HPVs.
The growing popularity and availability of over-the-counter (OTC) health products, including vitamins, raises serious concern about vitamin toxicity. We report a case of cirrhosis in a patient with habitual daily ingestion of an OTC dietary supplement that contained 13,000 microg vitamin A and was associated with marked clinical improvement after discontinuation. This case highlights the potential for liver damage that may be associated with long-term intake of OTC vitamin supplements, and indicates the need for medical supervision of such products.
BACKGROUND: Many different dietary supplements are being sold in North America. The quality of the evidence supporting their efficacy covers a wide spectrum: Some are based on solid science (such as vitamin D and fish oil), whereas with most supplements there is little or no supporting evidence. Types of supplements commonly sold include exotic fruit juices (such as goji juice) and single herbs or mixture of herbs. Common claims made in support of particular supplements are that they are rich in antioxidants, induce detoxification, stimulate the immune system, and cause weight loss. Supplements are commonly sold through health food stores and by multilevel marketing. Sales may be promoted using bulk mail ("junk mail"), spam e-mails, and Web sites. A large part of marketing is based on claims that are blatantly dishonest. CONCLUSIONS: Whereas supplements for which good supporting evidence exists generally cost around $3-$4 per month, those that are heavily promoted for which there is little supporting evidence cost about $20-$60 per month. The major cause of this problem in the United States is weakness of the law. There is an urgent need for stricter regulation and for giving better advice to the general public.
Vitamin A deficiency (VAD) has been recognized as a public-health issue in developing countries. Economic constraints, sociocultural limitations, insufficient dietary intake, and poor absorption leading to depleted vitamin A stores in the body have been regarded as potential determinants of the prevalence of VAD in South Asian developing countries. VAD is exacerbated by lack of education, poor sanitation, absence of new legislation and enforcement of existing food laws, and week monitoring and surveillance system. Several recent estimates confirmed higher morbidly and mortality rate among children and pregnant and non-pregnant women of childbearing age. Xerophthalmia is the leading cause of preventable childhood blindness with its earliest manifestations as night blindness and Bitot's spots, followed by blinding keratomalacia, all of which are the ocular manifestations of VAD. Children need additional vitamin A because they do not consume enough in their normal diet. There are three general ways for improving vitamin A status: supplementation, fortification, and dietary diversification. These approaches have not solved the problem in South Asian countries to the desired extent because of poor governmental support and supervision of vitamin A supplementation twice a year. An extensive review of the extant literature was carried out, and the data under various sections were identified by using a computerized bibliographic search via PubMed, Web of Science, and Google Scholar. All abstracts and full-text articles were examined, and the most relevant articles were selected for screening and inclusion in this review. Conclusively, high prevalence of VAD in South Asian developing countries leads to increased morbidity and mortality among infants, children, and pregnant women. Therefore, stern efforts are needed to address this issue of public-health significance at local and international level in lower- and middle-income countries of South Asia.
BACKGROUND: Vitamin and mineral supplements are commonly used to prevent chronic diseases. PURPOSE: To systematically review evidence for the benefit and harms of vitamin and mineral supplements in community-dwelling, nutrient-sufficient adults for the primary prevention of cardiovascular disease (CVD) and cancer. DATA SOURCES: MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Database of s of Reviews of Effects were searched from January 2005 to 29 January 2013, with manual searches of reference lists and gray literature. STUDY SELECTION: Two investigators independently selected and reviewed fair- and good-quality trials for benefit and fair- and good-quality trials and observational studies for harms. DATA EXTRACTION: Dual quality assessments and data abstraction. DATA SYNTHESIS: Two large trials (n = 27 658) reported lower cancer incidence in men taking a multivitamin for more than 10 years (pooled unadjusted relative risk, 0.93 [95% CI, 0.87 to 0.99]). The study that included women showed no effect in that group. High-quality studies (k = 24; n = 324 653) of single and paired nutrients (such as vitamins A, C, or D; folic acid; selenium; or calcium) were scant and heterogeneous and showed no clear evidence of benefit or harm. Neither vitamin E nor β-carotene prevented CVD or cancer, and β-carotene increased lung cancer risk in smokers. LIMITATIONS: The analysis included only primary prevention studies in adults without known nutritional deficiencies. Studies were conducted in older individuals and included various supplements and doses under the set upper tolerable limits. Duration of most studies was less than 10 years. CONCLUSION: Limited evidence supports any benefit from vitamin and mineral supplementation for the prevention of cancer or CVD. Two trials found a small, borderline-significant benefit from multivitamin supplements on cancer in men only and no effect on CVD. PRIMARY FUNDING SOURCE: Agency for Healthcare Research and Quality.
Background: Dietary antioxidants may protect against DNA damage induced by endogenous and exogenous sources, including ionizing radiation (IR), but data from IR-exposed human populations are limited. Objective: The objective was to examine the association between the frequency of chromosome translocations, as a biomarker of cumulative DNA damage, and intakes of vitamins C and E and carotenoids in 82 male airline pilots. Design: Dietary intakes were estimated by using a self-administered semiquantitative food-frequency questionnaire. Translocations were scored by using fluorescence in situ hybridization with whole chromosome paints. Negative binomial regression was used to estimate rate ratios and 95% CIs, adjusted for potential confounders. Results: Significant and inverse associations were observed between translocation frequency and intakes of vitamin C, β-carotene, β-cryptoxanthin, and lutein-zeaxanthin from food (P < 0.05). Translocation frequency was not associated with the intake of vitamin E, α-carotene, or lycopene from food; total vitamin C or E from food and supplements; or vitamin C or E or multivitamin supplements. The adjusted rate ratios (95% CI) for ≥median compared with <median servings per week of high–vitamin C fruit and vegetables, citrus fruit, and green leafy vegetables were 0.61 (0.43, 0.86), 0.64 (0.46, 0.89), and 0.59 (0.43, 0.81), respectively. The strongest inverse association was observed for ≥median compared with <median combined intakes of vitamins C and E, β-carotene, β-cryptoxanthin, and lutein-zeaxanthin from food: 0.27 (0.14, 0.55). Conclusion: High combined intakes of vitamins C and E, β-carotene, β-cryptoxanthin, and lutein-zeaxanthin from food, or a diet high in their food sources, may protect against cumulative DNA damage in IR-exposed persons.
For many years, the prevailing concept was that LDL oxidation plays the central role in atherogenesis. As a consequence, supplementation of antioxidants, particularly vitamin E, became very popular. Unfortunately, major randomized clinical trials yielded disappointing results and recent meta-analyses concluded that indiscriminate, high dose vitamin E supplementation results in increased mortality. This conclusion raised (quite reasonable) criticism, much of which referred to the characteristics of meta-analysis. In our recent study, we used a Markov-model approach, which is free of most of the limitations of meta-analyses. Our major finding was that the average quality-adjusted life years (QALY) of vitamin E- supplemented individuals was 0.30 QALY (95%CI 0.21 to 0.39) less than that of untreated people. In our view, this supports the view that indiscriminate supplementation of high dose vitamin E can not be recommended to the general public.In the present communication we address several recent studies that demonstrated negative effects of vitamin E and raise possible mechanisms that may be responsible for the harmful effects of vitamin E supplementation. We also review recent studies conducted with specific groups of patients that gained from vitamin E supplementation, indicating that although, on the average, indiscriminate supplementation of high dose vitamin E is not beneficial, specific populations may gain from vitamin E. The challenge is to establish selection criteria that will predict who is likely to benefit from vitamin E supplementation. Such criteria may be based either on the assumption that antioxidants are likely to be beneficial for people under oxidative stress or on knowledge regarding the benefit of sick people with certain diseases. In short, we adopt the view that vitamin E is a "double-edge sword" that should not be consumed until criteria are defined to predict who is likely to benefit from high dose supplementation of vitamin E. (c) 2009 International Union of Biochemistry and Molecular Biology, Inc.
High-dose β-carotene supplementation in high-risk persons has been linked to increased lung cancer risk in clinical trials; whether effects are similar in the general population is unclear. The authors examined associations of supplemental β-carotene, retinol, vitamin A, lutein, and lycopene with lung cancer risk among participants, aged 50–76 years, in the VITamins And Lifestyle (VITAL) cohort Study in Washington State. In 2000–2002, eligible persons (n = 77,126) completed a 24-page baseline questionnaire, including detailed questions about supplement use (duration, frequency, dose) during the previous 10 years from multivitamins and individual supplements/mixtures. Incident lung cancers (n = 521) through December 2005 were identified by linkage to the Surveillance, Epidemiology, and End Results cancer registry. Longer duration of use of individual β-carotene, retinol, and lutein supplements (but not total 10-year average dose) was associated with statistically significantly elevated risk of total lung cancer and histologic cell types; for example, hazard ratio = 2.02, 95% confidence interval: 1.28, 3.17 for individual supplemental lutein with total lung cancer and hazard ratio = 3.22, 95% confidence interval: 1.29, 8.07 for individual β-carotene with small-cell lung cancer for >4 years versus no use. There was little evidence for effect modification by gender or smoking status. Long-term use of individual β-carotene, retinol, and lutein supplements should not be recommended for lung cancer prevention, particularly among smokers.
BACKGROUND: Cod liver oil is an important source of vitamin D, but also contains other fat-soluble components such as vitamin A. Before 1999, the cod liver oil formula in Norway contained a high concentration of vitamin A (1000 µg per 5 ml). High vitamin A status is associated with increased risks of several chronic diseases. OBJECTIVE: To investigate the association between cod liver oil intake and asthma development. METHODS: In the Nord-Trøndelag Health Study, a total of 25 616 Norwegian adults aged 19-55 years were followed up from 1995-1997 to 2006-2008. Current analysis based on 17 528 subjects who were free of asthma and had complete information on cod liver oil intake at baseline. Cod liver oil intake was defined as daily intake ≥ 1 month during the year prior to baseline. Incident asthma was reported as new-onset asthma during the 11-year follow-up. RESULTS: Of the 17 528 subjects, 18% (n=3076) consumed cod liver oil daily for ≥ 1 month over the past year. Cod liver oil intake was significantly associated with incident asthma with an OR of 1.62 (95% CI 1.32 to 1.98) after adjustment for age, sex, daily smoking, physical activity, education, socio-economic status, family history of asthma, and body mass index (BMI). The positive association was consistent across age (< 40/≥ 40 years), sex (men/women), family history of asthma (yes/no) and BMI subgroups (< 25/≥ 25 kg/m(2)). CONCLUSIONS: Intake of cod liver oil with high vitamin A content was significantly associated with increased incidence of adult-onset asthma.