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Vitamin D and type 2 diabetes: are we ready for a prevention trial? Scragg R. Diabetes. 2008 Oct;57(10):2565-6. PMID: 18820212 doi: 10.2337/db08-0879 Despite evidence from the current article (3) and the Finnish study (17), doubts still remain about whether low vitamin status is a cause of type 2 diabetes. Further cohort studies are required, assessing baseline vitamin D status using blood 25(OH)D to be sure that the Ely and Finnish studies are not false-positive results. Glucose clamp studies are also required because we are still not sure of the mechanism influenced by vitamin D-whether it is insulin resistance, secretion, or both. But most importantly, given that nearly three decades have passed since the first studies linking vitamin D with insulin metabolism (6,7), well-designed clinical trials of the effect of vitamin D supplementation on glycemia status and diabetes risk are urgently required to settle this question. And they need to prevent past mistakes. In particular, the vitamin D dose given in such trials needs to be high enough-above 2,000 IU per day (19)-to raise blood 25(OH)D levels above 80 nmol/l because diabetes risk is lowest at this level (9,20). If well-designed trials are carried out and confirm a protective effect from vitamin D, it could be used by the general population as a simple and cheap solution to help prevent the diabetes epidemic.

Diagnosis and treatment of vitamin D deficiency. Cannell JJ, Hollis BW, Zasloff M, Heaney RP. Expert Opin Pharmacother. 2008 Jan;9(1):107-18. PMID: 18076342 The recent discovery - in a randomised, controlled trial - that daily ingestion of 1100 IU of colecalciferol (vitamin D) over a 4-year period dramatically reduced the incidence of non-skin cancers makes it difficult to overstate the potential medical, social and economic implications of treating vitamin D deficiency. Not only are such deficiencies common, probably the rule, vitamin D deficiency stands implicated in a host of diseases other than cancer. The metabolic product of vitamin D is a potent, pleiotropic, repair and maintenance, secosteroid hormone that targets > 200 human genes in a wide variety of tissues, meaning it has as many mechanisms of action as genes it targets. A common misconception is that government agencies designed present intake recommendations to prevent or treat vitamin D deficiency. They did not. Instead, they are guidelines to prevent particular metabolic bone diseases. Official recommendations were never designed and are not effective in preventing or treating vitamin D deficiency and in no way limit the freedom of the physician - or responsibility - to do so. At this time, assessing serum 25-hydroxy-vitamin D is the only way to make the diagnosis and to assure that treatment is adequate and safe. The authors believe that treatment should be sufficient to maintain levels found in humans living naturally in a sun-rich environment, that is, > 40 ng/ml, year around. Three treatment modalities exist: sunlight, artificial ultraviolet B radiation or supplementation. All treatment modalities have their potential risks and benefits. Benefits of all treatment modalities outweigh potential risks and greatly outweigh the risk of no treatment. As a prolonged 'vitamin D winter', centred on the winter solstice, occurs at many temperate latitudes, ≤ 5000 IU (125 μg) of vitamin D/d

Vitamin D requirements during lactation: high-dose maternal supplementation as therapy to prevent hypovitaminosis D for both the mother and the nursing infant. Hollis BW, Wagner CL. Am J Clin Nutr. 2004 Dec;80(6 Suppl):1752S-8S. PMID: 15585800

Dietary recommendations for vitamin D: a critical need for functional end points to establish an estimated average requirement. Whiting SJ, Calvo MS. J Nutr. 2005 Feb;135(2):304-9. Review. PMID: 15671232 In summary, vitamin D has emerged as a critical nutrient for which there is a compelling health need to establish adequate dietary guidelines in North America and worldwide given the increasing evidence of vitamin D deficiency and insufficient links to risk of chronic disease. We strongly argue that now there are enough data to consider setting an estimated average requirement for vitamin D and to recognize the crucial need for more research to determine the role of vitamin D in noncalciotropic functions and prevention of chronic diseases

Despite inadequacies in information concerning the minimum prophylactic requirement of vitamin D for all age groups beyond infancy, there is no doubt that a total intake of 400 I.U. per day is adequate to prevent vitamin D deficiency in substantially all normal children from birth through adolescence. Evidence derived from the study of idiopathic hypercalcemia suggests that certain infants excessively sensitive to the toxic action of vitamin D may, on rare occasions, be adversely affected by daily intakes of 3,000 to 4,000 I.U. and sometimes considerably less. Because of the prevalent practice of food fortification in the United States and Canada, there is now a definite possibility that the individual, even the young infant, may ingest considerably more than the recommended vitamin D allowance, and intakes of 2,000 to 3,500 I.U. per day are possible, particularly beyond infancy. Although there has been no specific evidence that intakes of this order produce deleterious effects beyond infancy, it is pointed out that the long-term consequences of this new nutritional situation on older children or adults are entirely unknown.

Defining Adequate Vitamin D Intake : Cross-sectional and Intervention Studies Viljakainen, Heli Tuulikki University of Helsinki 2008-05-23 Doctoral dissertation (article-based) Vitamin D is required for normal bone growth and maintenance of the skeleton throughout life. In Finland, like in many other Western countries, the population suffers from inadequate or deficient vitamin D status, especially during winter, which is thought to increase the risk of osteoporosis. New strategies to prevent osteoporosis are actively being sought. The main objective of this thesis was to determine whether vitamin D is feasible in the primary prevention of osteoporosis; does it affect bone mineral accrual during the growth period? A second goal was to ascertain whether seasonal variation in calcitropic hormones affects bone remodelling, and to elucidate the vitamin D intake needed to overcome this variation in different age groups. In summary, vitamin D intake remains inadequate among the target groups of this thesis, as reflected by seasonal variation in calcitropic hormones and bone metabolism. Dietary intake of vitamin D should be increased to achieve at least an adequate vitamin D status (S-25-OHD>50 nmol/l) and possibly an optimal vitamin D status (S-25-OHD>80 nmol/l) throughout the year. This could be accomplished by introducing new vitamin D-fortified foods to the market."

Prevention of rickets and vitamin D deficiency in infants, children, and adolescents.\nWagner CL, Greer FR; American Academy of Pediatrics Section on Breastfeeding; American Academy of Pediatrics Committee on Nutrition.\nPediatrics. 2008 Nov;122(5):1142-52. Erratum in: Pediatrics. 2009 Jan;123(1):197.\nPMID: 18977996

25(OH)D Serum levels decline with age earlier in women than in men and less efficiently prevent compensatory hyperparathyroidism in older adults. Maggio D, Cherubini A, Lauretani F, Russo RC, Bartali B, Pierandrei M, Ruggiero C, Macchiarulo MC, Giorgino R, Minisola S, Ferrucci L. J Gerontol A Biol Sci Med Sci. 2005 Nov;60(11):1414-9. PMID: 16339327 Conclusions. These findings suggest that the age-associated fall of serum 25(OH)D starts earlier in women than in men and that higher levels of 25(OH)D are required in older compared to younger persons to avoid the age-associated compensatory hyperparathyroidism.

Vitamin D and intervention trials in prostate cancer: from theory to therapy. Schwartz GG. Ann Epidemiol. 2009 Feb;19(2):96-102. Epub 2008 Jul 10. PMID: 18619854 doi:10.1016/j.annepidem.2008.03.007 This suggests that whereas vitamin D (e.g., cholecalciferol) might prevent prostate cancer, existing prostate tumors likely would require treatment with 1,25(OH)(2)D and/or its analogs. The major obstacle to the use of 1,25(OH)(2)D in patients therapeutically is the risk of hypercalcemia. Several maneuvers to reduce this risk, including pulse dosing and the use of less calcemic 1,25(OH)(2)D analogs, have been explored in Phase I-III clinical trials. Once merely a promise, vitamin D-based therapies for prostate cancer may soon be medical practice.

Grant WB, Holick MF. Benefits and requirements of vitamin D for optimal health: a review. Altern Med Rev. 2005 Jun;10(2):94-111. Review. PMID: 15989379

"Thursday, 17 December 2009 This blog is in response to Dr Briffa's post here. as I keep having problems commenting on his blogs. While 44ng/ml is sufficient to not only maximize uptake of calcium (>32ng/ml) and ensure maximum bone mineral density (>42ng/ml), pregnant and nursing mothers should be aware that in order to maximize the amount of vitamin D3 in human breast milk 6400iu/daily was found to be necessary to raise (>58ng/ml) at latitude 32. This is detailed in the Taylor, Wagner and Hollis paper. Vitamin D supplementation during lactation to support infant and mother. Although 4000iu/daily met the mothers daily needs in full it left babies being born with lower 25(OH)D status than required for optimum calcium absorption They also found DAILY use of supplements was required by pregnant and nursing mothers to ensure an even daily Vitamin D3 supply to the foetus & baby. It makes virtually no measurable difference for everyone else if you supplement daily or weekly. While Dr Briffa will not be lactating he may be interested seeing in the Grassrootshealth chart showing disease incidence by 25(OH)D status. this may encourage him to go just another 10ng/ml higher and a bit nearer to the natural level at which human breast milk flows replete with D3."

Vitamin D and skin physiology: a D-lightful story. Holick MF, Chen TC, Lu Z, Sauter E. J Bone Miner Res. 2007 Dec;22 Suppl 2:V28-33. PMID: 18290718 doi: 10.1359/jbmr.07s211 Very few foods naturally contain vitamin D, and those that do have a very variable vitamin D content. Recently it was observed that wild caught salmon had between 75% and 90% more vitamin D(3) compared with farmed salmon. The associations regarding increased risk of common deadly cancers, autoimmune diseases, infectious diseases, and cardiovascular disease with living at higher latitudes and being prone to vitamin D deficiency should alert all health care professionals about the importance of vitamin D for overall health and well being. Humans have depended on sunlight for their vitamin D requirement. The impact of season, time of day, and latitude on vitamin D synthesis is well documented.(2,3) We now report that altitude also has a dramatic influence on vitamin D3 production and that living at altitudes above 3500 m permits previtamin D3 production at a time when very little is produced at latitudes below 3400 m. It was surprising that, at 27° N in Agra (169 M), little previtamin D3 production was observed. However, there was significant air pollution that caused a haze over the city. It is likely the ozone and other UVB-absorbing pollutants in the air prevented the solar UVB photons from reaching the earth's surface to produce previtamin D3.

For many years, vitamin D was boring--even to doctors. Because it was considered good for bones and not much else, multitaskers like vitamin A, B vitamins and vitamin E hogged all the press. But recent studies have thrust this long-neglected nutrient into the spotlight. Scientists now think vitamin D may affect everything from diabetes to cancer. They're also finding that many people don't have enough of it.

This web site is dedicated to vitamin D and cancer. This is because exciting new research indicates that vitamin D-whether produced in the skin as a result of exposure to ultraviolet radiation (from sunlight or sun lamps) or obtained from supplementation with cholecalciferol (vitamin D3)-may help cancer patients. However, the research is far from complete.