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Effectiveness and safety of vitamin D in relation to bone health. Cranney A, Horsley T, O'Donnell S, Weiler H, Puil L, Ooi D, Atkinson S, Ward L, Moher D, Hanley D, Fang M, Yazdi F, Garritty C, Sampson M, Barrowman N, Tsertsvadze A, Mamaladze V. Evid Rep Technol Assess (Full Rep). 2007 Aug;(158):1-235. Review. PMID: 18088161 CONCLUSIONS: The results highlight the need for additional high quality studies in infants, children, premenopausal women, and diverse racial or ethnic groups. There was fair evidence from studies of an association between circulating 25(OH)D concentrations with some bone health outcomes (established rickets, PTH, falls, BMD). However, the evidence for an association was inconsistent for other outcomes (e.g., BMC in infants and fractures in adults). It was difficult to define specific thresholds of circulating 25(OH)D for optimal bone health due to the imprecision of different 25(OH)D assays. Standard reference preparations are needed so that serum 25(OH)D can be accurately and reliably measured, and validated. In most trials, the effects of vitamin D and calcium could not be separated. Vitamin D(3) (>700 IU/day) with calcium supplementation compared to placebo has a small beneficial effect on BMD, and reduces the risk of fractures and falls although benefit may be confined to specific subgroups. Vitamin D intake above current dietary reference intakes was not reported to be associated with an increased risk of adverse events. However, most trials of higher doses of vitamin D were not adequately designed to assess long-term harms.

BACKGROUND: To determine the effect of vitamin D binding protein (DBP) genotypes on 25-hydroxyvitamin D [25(OH)D] changes with vitamin D supplements, we studied 98 adults receiving 600 or 4000 IU/d vitamin D(3) for one year. METHODS: The DBP functional variant, T436K, was genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). RESULTS: Mean 25(OH)D increases were 97% for TT (n=48), 151% for TK (n=31) and 307% (n=6) for KK genotypes (p=.004). CONCLUSIONS: As with baseline 25(OH)D, T436K genotype predicts 25(OH)D changes after long-term vitamin D supplementation. Common genetic variants of the vitamin D binding protein (DBP) predict differences in response of serum 25-hydroxyvitamin D [25(OH)D] to vitamin D supplementation. Fu L, Yun F, Oczak M, Wong BY, Vieth R, Cole DE. Clin Biochem. 2009 Jul;42(10-11):1174-7. Epub 2009 Mar 18. PMID: 19302999

Current impediments to acceptance of the ultraviolet-B-vitamin D-cancer hypothesis. Grant WB, Boucher BJ. Anticancer Res. 2009 Sep;29(9):3597-604. PMID: 19667154 The ultraviolet-B (UVB)-vitamin D-cancer hypothesis was proposed in 1980. There have been numerous ecological, observational and other studies of the hypothesis. There are about 14 types of cancer for which it seems to apply: bladder, breast, colon, endometrial, esophageal, gallbladder, gastric, ovarian, pancreatic, rectal, renal and vulvar cancer and both Hodgkin's and non-Hodgkin's lymphoma. Nonetheless, the hypothesis has not yet been accepted by public health agencies. Some of the reasons for this include a distrust of ecological studies, some mistrust of observational studies, and the existence of just one positive randomized controlled trial, an analysis of a vitamin D and calcium supplementation study involving post-menopausal women in Nebraska. Paradigm shifts such as this generally take time, in part due to opposition from those content with the status quo. In this paper, results of ecological studies in the United States using summertime solar UVB as the index of vitamin D production, which is highly asymmetrical with respect to latitude, and indices for other cancer risk-modifying factors (air pollution, alcohol consumption, dietary iron and zinc, ethnic background, socioeconomic status, smoking and urban/rural residence) are discussed in terms of supporting the hypothesis. These studies were not considered while other ecological studies were examined in recent critiques of the hypothesis. While additional randomized controlled trials would, of course, be helpful, the current evidence seems to satisfy the criteria for causality as outlined by A. Bradford Hill.

Using these functional indicators, several studies have more accurately defined vitamin D deficiency as circulating levels of 25(OH)D ≤ 80 nmol or 32 µg/L. Recent studies reveal that current dietary recommendations for adults are not sufficient to maintain circulating 25(OH)D levels at or above this level, especially in pregnancy and lactation. Circulating 25-hydroxyvitamin D levels indicative of vitamin D sufficiency: implications for establishing a new effective dietary intake recommendation for vitamin D. Hollis BW. J Nutr. 2005 Feb;135(2):317-22. Review. PMID: 15671234 [

Vitamin D deficiency is the cause of common obesity. Foss YJ. Med Hypotheses. 2009 Mar;72(3):314-21. Epub 2008 Dec 2. PMID: 19054627 doi:10.1016/j.mehy.2008.10.005 Common obesity and the metabolic syndrome may therefore result from an anomalous adaptive winter response. The stimulus for the winter response is proposed to be a fall in vitamin D. The synthesis of vitamin D is dependent upon the absorption of radiation in the ultraviolet-B range of sunlight. At ground level at mid-latitudes, UV-B radiation falls in the autumn and becomes negligible in winter. It has previously been proposed that vitamin D evolved in primitive organisms as a UV-B sensitive photoreceptor with the function of signaling changes in sunlight intensity. It is here proposed that a fall in vitamin D in the form of circulating calcidiol is the stimulus for the winter response, which consists of an accumulation of fat mass (obesity) and the induction of a winter metabolism (the metabolic syndrome). Vitamin D deficiency can account for the secular trends in the prevalence of obesity and for individual differences in its onset and severity. It may be possible to reverse the increasing prevalence of obesity by improving vitamin D status.

Is the MP Treatment for Sarcoidosis Helpful for Other Chronic Diseases? MP's Vitamin D Theories Are Not Supported by Lab Studies. Updated July 2, 2008 "The MP treatment plan was originally designed to treat an inflammatory condition known as sarcoidosis. The treatment consists of using the drug Benicar, combined with the avoidance of all sources of vitamin D, and eventually adding various antibiotics, especially minocycline. After being used by sarcoidosis patients for some years, it was then theorized and claimed that the treatment could treat other inflammatory conditions. Eventually it was also claimed that it could treat fibromyalgia and CFS, conditions which are not recognized by the medical literature as being inflammatory in nature. "

"For more than 80 years, scientists have known that vitamin D is important for building bones. And for most of those 80 years, people thought this was the only thing it was good for. In the past decade, however, we've learned two important things about vitamin D: it appears to have many other important health effects, and many Americans don't get enough of it. In 2008, new research pointed to a vitamin D deficiency as a possible contributing factor in heart disease. And the suspected link between vitamin D deficiency and cancer grew even stronger. This surely will spur much new research in 2009. Why is vitamin D deficiency so common? The vitamin is made in our skin when sunlight strikes it. Many Americans-especially those who live in the northern part of the country, are elderly or have dark skin-don't soak up enough sun. And the vitamin isn't found in many foods. The main sources are fatty fish (such as salmon, mackerel, herring and sardines) and milk, cereal and juices that have been fortified with it. Vitamin D deficiency often is unsuspected because it causes no direct symptoms; like high blood pressure, it does its damage silently."

Annual intramuscular injection of a megadose of cholecalciferol for treatment of vitamin D deficiency: efficacy and safety data. Diamond TH, Ho KW, Rohl PG, Meerkin M. Med J Aust. 2005 Jul 4;183(1):10-2. PMID: 15992330 Conclusions: Once-yearly intramuscular cholecalciferol injection (600 000 IU) is effective therapy for vitamin D deficiency. While this therapy appears to be safe, the potential for developing hypercalciuria needs to be examined in a large randomised controlled trial.

Dietary Reference Intakes for Vitamin D and Calcium An IOM committee has been named to undertake a study to assess current relevant data and update as appropriate the DRIs for vitamin D and calcium. The review will include consideration of chronic and non-chronic disease indicators. The study will also incorporate, as appropriate, systematic evidence-based reviews of the literature and an assessment of potential indicators of adequacy and of excess intake. Indicators for adequacy and excess will be selected based on the strength and quality of the evidence and the demonstrated public health significance, taking into consideration sources of uncertainty in the evidence.

Vitamin D and living in northern latitudes--an endemic risk area for vitamin D deficiency. Huotari A, Herzig KH. Int J Circumpolar Health. 2008 Jun;67(2-3):164-78. Review. PMID: 18767337 CONCLUSIONS: Vitamin D plays a fundamental role in calcium and phosphate homeostasis. A deficiency of vitamin D has been attributed to several diseases. Since its production in the skin depends on exposure to UVB-radiation via the sunlight, the level of vitamin D is of crucial importance for the health of inhabitants who live in the Nordic latitudes where there is diminished exposure to sunlight during the winter season. Therefore, fortification or supplementation of vitamin D is necessary for most of the people living in the northern latitudes during the winter season to maintain adequate levels of circulating 25(OH)D3 to maintain optimal body function and prevent diseases.

The following table provides factors for converting conventional units to SI units for selected clinical data. Source: JAMA Author Instructions. Contains also conversion factors for circulating form of vitamin D, 25(OH)D (calcidiol).

An acknowledged benefit of exposure to ultraviolet radiation is synthesis of vitamin D in human skin. Here we have defined a standard vitamin D dose based upon recommended requirements for vitamin D, and present a simplified web-based tool that enables the user to calculate associated exposure times for any time and place ( http://nadir.nilu.no/~olaeng/fastrt/VitD-ez_quartMED.html). This www page is a simplified version of the more complex web tool ( http://nadir.nilu.no/~olaeng/fastrt/VitD_quartMED.html). The simplified www page is convenient for users unfamiliar to radiative transfer modelling, because the model input is limited and more intuitive.

An acknowledged benefit of exposure to ultraviolet radiation is synthesis of vitamin D in human skin. Here we have defined a standard vitamin D dose based upon recommended requirements for vitamin D, and present a web-based tool that enables the user to calculate associated exposure times for any time and place ( http://nadir.nilu.no/~olaeng/fastrt/VitD_quartMED.html). The recommended UV exposure times depends on latitude, time, total ozone, clouds, aerosols, surface reflectivity and altitude all of which can be specified by the user. A simpler version for non-experts is available at http://nadir.nilu.no/~olaeng/fastrt/VitD-ez_quartMED.html

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Plasma 25-hydroxyvitamin d is associated with markers of the insulin resistant phenotype in nondiabetic adults. Liu E, Meigs JB, Pittas AG, McKeown NM, Economos CD, Booth SL, Jacques PF. J Nutr. 2009 Feb;139(2):329-34. Epub 2008 Dec 23. PMID: 19106328 doi:10.3945/jn.108.093831 After adjusting for age and sex, plasma 25(OH)D was positively associated with ISI(0,120), plasma adiponectin, and HDL cholesterol and inversely associated with plasma triacylglycerol, but these associations were no longer significant after further adjustment for BMI, waist circumference, and current smoking status. 25(OH)D and 2-h post-OGTT glucose were not associated. Among adults without diabetes, vitamin D status was inversely associated with surrogate fasting measures of insulin resistance. These results suggest that vitamin D status may be an important determinant for type 2 diabetes mellitus.

A critical review of Vitamin D and cancer: A report of the IARC Working Group on vitamin D William B. Grant Dermato-Endocrinology. Volume 1, Issue 1 January/February 2009 Pages: 25 - 33 The International Agency for Research on Cancer (IARC) released a report, Vitamin D and Cancer, on November 25, 2008. The report focused on the current state of knowledge and level of evidence of a causal association between vitamin D status and cancer risk. Although presenting and evaluating evidence for the beneficial role of UVB and vitamin D in reducing the risk of cancer, it discounted or omitted important evidence in support of the efficacy of vitamin D. The report largely dismissed or ignored ecological studies on the grounds that confounding factors might have affected the findings. The report accepted a preventive role of vitamin D in colorectal cancer but not for breast cancer.

In the last post, we talked about the new report on vitamin D and cancer from the International Agency for Research into Cancer (IARC). In this one, we'll summarise what the report has to say on the balance between getting enough vitamin D through sun exposure and reducing the risk of skin cancer by being SunSmart. IARC calls for more trials to really pin down the effects of vitamin D supplements - either positive or negative - depending on how much vitamin D people already have in their system. Until then, they feel that there is no solid basis for changing any existing recommendations about vitamin D.

Clinical Responses to a Mega-dose of Vitamin D3 in Infants and Toddlers With Vitamin D Deficiency Rickets. Soliman AT, El-Dabbagh M, Adel A, Ali MA, Aziz Bedair EM, Elalaily RK. J Trop Pediatr. 2009 Jun 8. [Epub ahead of print] PMID: 19506025 doi:10.1093/tropej/fmp040 Conclusion: An IM injection of a mega dose of cholecalciferol is a safe and effective therapy for treatment of VDD rickets in infants and toddlers with normalization of all the biochemical parameters and healing of radiological manifestations. Measurement of serum 25(OH)D level is highly recommended in all short children with a clear need for a general vitamin D supplementation for all infants and young children in Qatar.

In his recent essay, Trevor G. Marshall explores how vitamin D supplementation may be contributing to the current epidemics of obesity and chronic disease[1]. Unfortunately, he has overlooked many important papers that disagree with his hypothesis. This letter points out some of the omissions. The health benefits of vitamin D3 have been reviewed recently[2]. The benefits for bone health have been known for nearly a century. Benefits for cancer, infectious diseases, autoimmune diseases, and metabolic diseases have been identified in the past three decades.