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Holick, M. F., MacLaughlin, J. A. & Doppelt, S. H. (1981) Factors that influence the cutaneous photosynthesis of previtamin D3. Science 211:590-593 When human skin was exposed to simulated solar ultraviolet radiation, epidermal 7-dehydrocholesterol was converted to previtamin D3. During prolonged exposure to simulated solar ultraviolet radiation, the synthesis of previtamin D3 reached a plateau at about 10 to 15 percent of the original 7-dehydrocholesterol content, and previtamin D3 was photoisomerized to two biologically inert isomers, lumisterol3 and tachysterol3. Increases either in skin melanin concentration or in latitude necessitated increases in the exposure time to simulated solar ultraviolet radiation required to maximize the formation, but not the total content, of previtamin D3. In order of importance, the significant determinants limiting the cutaneous production of previtamin D3 are (i) photochemical regulation, (ii) pigmentation, and (iii) latitude.

Vitiligo (Leucoderma / White patches) is a condition in which skin loses the pigment melanin that determines its color. Treat Vitiligo / Leucoderma / White patches with Homeopathy Dr. Batra's

The role of vitamin D in cancer prevention. Garland CF, Garland FC, Gorham ED, Lipkin M, Newmark H, Mohr SB, Holick MF. Am J Public Health. 2006 Feb;96(2):252-61. Epub 2005 Dec 27. Review. PMID: 16380576 DOI: 10.2105/AJPH.2004.045260 Vitamin D status differs by latitude and race, with residents of the northeastern United States and individuals with more skin pigmentation being at increased risk of deficiency. A PubMed database search yielded 63 observational studies of vitamin D status in relation to cancer risk, including 30 of colon, 13 of breast, 26 of prostate, and 7 of ovarian cancer, and several that assessed the association of vitamin D receptor genotype with cancer risk. The majority of studies found a protective relationship between sufficient vitamin D status and lower risk of cancer. The evidence suggests that efforts to improve vitamin D status, for example by vitamin D supplementation, could reduce cancer incidence and mortality at low cost, with few or no adverse effects

Serum 25-hydroxyvitamin D status of vegetarians, partial vegetarians, and nonvegetarians: the Adventist Health Study-2. Chan J, Jaceldo-Siegl K, Fraser GE. Am J Clin Nutr. 2009 May;89(5):1686S-1692S. Epub 2009 Apr 1. PMID: 19339396 Conclusions: s25(OH)D concentrations were not associated with vegetarian status. Other factors, such as vitamin D supplementation, degree of skin pigmentation, and amount and intensity of sun exposure have greater influence on s25(OH)D than does diet.

The role of vitamin D in cancer prevention. Garland CF, Garland FC, Gorham ED, Lipkin M, Newmark H, Mohr SB, Holick MF. Am J Public Health. 2006 Feb;96(2):252-61. Epub 2005 Dec 27. Review. PMID: 16380576 DOI: 10.2105/AJPH.2004.045260 Vitamin D status differs by latitude and race, with residents of the northeastern United States and individuals with more skin pigmentation being at increased risk of deficiency. A PubMed database search yielded 63 observational studies of vitamin D status in relation to cancer risk, including 30 of colon, 13 of breast, 26 of prostate, and 7 of ovarian cancer, and several that assessed the association of vitamin D receptor genotype with cancer risk. The majority of studies found a protective relationship between sufficient vitamin D status and lower risk of cancer. The evidence suggests that efforts to improve vitamin D status, for example by vitamin D supplementation, could reduce cancer incidence and mortality at low cost, with few or no adverse effects.

Vitamin D deficiency is a very serious health problem. Most people tend to think of it only in terms of skeletal problems; however, it is much more than that. Vitamin D deficiency has now been linked with a multitude of neoplasms, autoimmune dysfunction, compromised innate immunity and neurodevelopment in utero. Vitamin D is made in huge amounts when we go into intense sun. A fair-skinned individual can produce approximately 20,000 IU in 10 minutes' time with a total body exposure. A person with significant pigmentation will require up to 10 times the exposure to make an equivalent amount. In the winter at the latitude of Chicago, even a fair person cannot photo-produce vitamin D from mid-October through March. Thus, it is VERY important to have a realistic vitamin D recommendation as the current 200 IU/day recommendation is a joke

Robert P. Heaney is John A. Creighton University Professor, Creighton University, Omaha, Nebraska, United States. Hominid evolution took place in an environment (equatorial East Africa) that provided a superabundance of both calcium and vitamin D, the first in available foods and the second through conversion of 7-dehydrocholesterol to pre-vitamin D in the skin, a reaction catalysed by the intense solar ultraviolet (UV) radiation. Seemingly as a consequence, the evolving human physiology incorporated provisions to prevent the potential of toxic excesses of both nutrients. For vitamin D the protection was of two sorts: skin pigmentation absorbed the critical UV wavelengths and thereby limited dermal synthesis of cholecalciferol; and slow delivery of vitamin D from the skin into the bloodstream left surplus vitamin in the skin, where continuing sun exposure led to its photolytic degradation to inert compounds. For calcium, the adaptation consisted of very inefficient calcium absorption, together with poor to absent systemic conservation. The latter is reflected in unregulated dermal calcium losses, a high sensitivity of renal obligatory calcium loss to other nutrients in the diet and relatively high quantities of calcium in the digestive secretions. Today, chimpanzees in the original hominid habitat have diets with calcium nutrient densities in the range of 2 to 2.5 mmol per 100 kcal, and hunter-gatherer humans in Africa, South America and New Guinea still have diets very nearly as high in calcium (1.75 to 2 mmol per 100 kcal) (Eaton and Nelson, 1991). With energy expenditure of 3 000 kcal per day (a fairly conservative estimate for a contemporary human doing physical work), such diets would provide substantially in excess of 50 mmol of calcium per day. By contrast, median intake in women in North America and in many European countries today is under 15 mmol per day. Two factors altered the primitive situation: the migration of humans from Africa to higher latitude

High-dose vitamin D3 supplementation in a cohort of breastfeeding mothers and their infants: a 6-month follow-up pilot study. Wagner CL, Hulsey TC, Fanning D, Ebeling M, Hollis BW. Breastfeed Med. 2006 Summer;1(2):59-70. PMID: 17661565 doi:10.1089/bfm.2006.1.59. Objective: To examine the effect of high-dose maternal vitamin D3 (vitD) supplementation on the nutritional vitD status of breastfeeding (BF) women and their infants compared with maternal and infant controls receiving 400 and 300 IU vitD/day, respectively. Design: Fully lactating women (n = 19) were enrolled at 1-month postpartum into a randomized- control pilot trial. Each mother received one of two treatments for a 6-month study period: 0 or 6000 IU vitD3 plus a prenatal vitamin containing 400 IU vitD3. The infants of mothers assigned to the control group received 300 IU vitD3/day; those infants of mothers in the high-dose group received 0 IU (placebo). Maternal serum and milk vitD and 25(OH)D were measured at baseline then monthly; infant serum vitD and 25(OH)D were measured at baseline, and months 4 and 7. Urinary calcium/creatinine ratios were measured monthly in both mothers and infants. Dietary and BF history and outdoor activity questionnaires were completed at each visit. Changes in skin pigmentation were measured by spectrophotometry. Data were analyzed using chi-square, t-test, and analysis of variance (ANOVA) on an intent-to-treat basis. Conclusion: With limited sun exposure, an intake of 400 IU/day vitamin D3 did not sustain circulating maternal 25(OH)D levels, and thus, supplied only extremely limited amounts of vitamin D to the nursing infant via breast milk. Infant levels achieved exclusively through maternal supplementation were equivalent to levels in infants who received oral vitamin D supplementation. Thus, a maternal intake of 6400 IU/day vitamin D elevated circulating 25(OH)D in both mother and nursing infant.

Autism and vitamin D. Cannell JJ. Med Hypotheses. 2008;70(4):750-9. Epub 2007 Oct 24. PMID: 17920208

Factors that influence the cutaneous synthesis and dietary sources of vitamin D.\nChen TC, Chimeh F, Lu Z, Mathieu J, Person KS, Zhang A, Kohn N, Martinello S, Berkowitz R, Holick MF.\nArch Biochem Biophys. 2007 Apr 15;460(2):213-7. Epub 2007 Jan 8.\nPMID: 17254541\ndoi:10.1016/j.abb.2006.12.017\n