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Serum levels of vitamin D metabolites and breast cancer risk in the prostate, lung, colorectal, and ovarian cancer screening trial. Freedman DM, Chang SC, Falk RT, Purdue MP, Huang WY, McCarty CA, Hollis BW, Graubard BI, Berg CD, Ziegler RG. Cancer Epidemiol Biomarkers Prev. 2008 Apr;17(4):889-94. Epub 2008 Apr 1. PMID: 18381472 doi: 10.1158/1055-9965.EPI-07-2594 In this prospective study of postmenopausal women, we did not observe an inverse association between circulating 25(OH)D or 1,25(OH)2D and breast cancer risk, although we cannot exclude an association in younger women or with long-term or earlier exposure

Why would vitamin D be prescribed when vitamin D3 is available over-the-counter? Let's review the known differences between vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol): --D3 is the human form; D2 is the non-human form found in plants. --Dose for dose, D3 is more effective at raising blood levels of 25-hydroxy vitamin D than D2. It requires roughly twice to 250% of the dose of D2 to match that of D3 (Trang H et al 1998). --D2 blood levels don't yield long-term sustained levels of 25-hydroxy vitamin D as does D3. When examined as a 28-day area under the curve (AUC--a superior measure of biologic exposure), D3 yields better than a 300% increased potency compared to D2. This means that it requires around 50,000 units D2 to match the effects of 15,000 units D3 (Armas LA et al 2004). --D2 has lower binding affinity for vitamin D-binding protein, compared to D3 --Mitochondrial vitamin D 25-hydroxylase converts D3 to the 25-hydroxylated form five times more rapidly than D2. --As we age, the ability to metabolize D2 is dramatically reduced, while D3 is not subject to this phenomenon

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.

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

Vitamin D: a D-Lightful health perspective. Holick MF. Nutr Rev. 2008 Oct;66(10 Suppl 2):S182-94. Review. PMID: 18844847 DOI: 10.1111/j.1753-4887.2008.00104.x Sunlight provides most humans with their vitamin D requirement. Adequate vitamin D(3) by synthesis in the skin or from dietary and supplemental sources is essential for bone health throughout life. Vitamin D deficiency is defined as a 25(OH)D concentration 30 ng/mL (75 nmol/L), and insufficiency as 21-29 ng/mL. Vitamin D deficiency and insufficiency has been linked to a wide variety of chronic diseases including common cancers, autoimmune, cardiovascular, and infectious diseases. Healthcare professionals need to be aware of the vitamin D deficiency pandemic. Guidelines for sensible sun exposure and supplemental vitamin D of 800-1000 IU/day are needed.

Differences in vitamin D status between countries in young adults and the elderly. McKenna MJ. Am J Med. 1992 Jul;93(1):69-77. PMID: 1385673 PURPOSE: To compare vitamin D status between countries in young adults and in the elderly. MATERIALS AND METHODS: Reports on vitamin D status (as assessed by serum 25-hydroxyvitamin D) from 1971 to 1990 were reviewed. Studies were grouped according to geographic regions: North America (including Canada and the United States); Scandinavia (including Denmark, Finland, Norway, and Sweden); and Central and Western Europe (including Belgium, France, Germany, Ireland, The Netherlands, Switzerland, and the United Kingdom). RESULTS: Vitamin D status varies with the season in young adults and in the elderly, and is lower during the winter in Europe than in both North America and Scandinavia. Oral vitamin D intake is lower in Europe than in both North America and Scandinavia. Hypovitaminosis D and related abnormalities in bone chemistry are most common in elderly residents in Europe but are reported in all elderly populations. CONCLUSIONS: The vitamin D status in young adults and the elderly varies widely with the country of residence. Adequate exposure to summer sunlight is the essential means to ample supply, but oral intake augmented by both fortification and supplementation is necessary to maintain baseline stores. All countries should adopt a fortification policy. It seems likely that the elderly would benefit additionally from a daily supplement of 10 micrograms of vitamin D.

Low serum 25-hydroxyvitamin D concentrations and secondary hyperparathyroidism in middle-aged white strict vegetarians. Lamberg-Allardt C, Kärkkäinen M, Seppänen R, Biström H. Am J Clin Nutr. 1993 Nov;58(5):684-9. PMID: 8237875 In conclusion, white strict vegetarians are at risk of vitamin D deficiency, at least in the winter, primarily because of a low dietary vitamin D intake, despite a normal sunlight exposure in summer. Low serum 25(OH)D concentrations are accompanied by high S-iPTH concentrations, which also are affected by a low calcium intake. The effect of these changes on bone health remains to be evaluated.

Prostate cancer risk and prediagnostic serum 25-hydroxyvitamin D levels (Finland). Ahonen MH, Tenkanen L, Teppo L, Hakama M, Tuohimaa P. Cancer Causes Control. 2000 Oct;11(9):847-52. PMID: 11075874 DOI: 10.1023/A:1008923802001 CONCLUSIONS: We conclude that low levels of 25-VD associated with an increased risk for subsequent earlier exposure and more aggressive development of prostate cancer, especially before the andropause.

This is a very long newsletter. I will answer questions about oil versus water-soluble Vitamin D, depression, mental clarity, malignant melanoma, Crohn's disease, an imagist poet, multiple sclerosis, sun-exposure, high-intensity red light and collagen repair in the skin, non-alcoholic fatty liver disease, influenza, the 1918 influenza pandemic, statins, the new Food and Nutrition Board, thyroid disease, chronic fatigue syndrome, athletes, the upcoming 14th Vitamin D Workshop, prostate cancer, the wrong blood test, pregnancy, autism, Alzheimer's disease, soap and sebum, asthma, sleep, the co-factors vitamin D needs to work (all contained in spinach), and-my favorite-UVC light and Vitamin D

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.

Research finds people with gene variant who lack vitamin D, produced from sun exposure, can develop condition

Vitamin D, found in fish and produced by sun exposure, can help stave off the mental decline that can affect people in old age, a study has suggested. UK and US researchers looked at 2,000 people aged 65 and over.

ScienceDaily (Feb. 10, 2009) - Vitamin D is significantly associated with muscle power and force in adolescent girls, according to a new study. Although vitamin D is naturally produced in the body through exposure to direct sunlight, vitamin D deficiency has become widely common in the United States. Vitamin D deficiency has been shown to have a significant negative impact on muscle and bone health, and can lead to conditions including osteoporosis and rickets.

"Under year round UV exposure conditions (low latitudes, broken line, "High UV") there is no association between 25(OH)D and either prostate or pancreatic cancer. At high latitudes (Solid line, "Low UV") there is a positive association between blood levels of 25(OH)D and these cancers. The average year round levels of 25(OH)D actually tend to be higher in northern latitudes, higher than those where there is year-round solar UVB. Vieth explains that we know almost nothing about the enzymes controlling tissue 1,25(OH)2D levels and much of his discussion is extrapolated from renal enzyme activity."

The high prevalence of vitamin D insufficiency across Australian populations is only partly explained by season and latitude. van der Mei IA, Ponsonby AL, Engelsen O, Pasco JA, McGrath JJ, Eyles DW, Blizzard L, Dwyer T, Lucas R, Jones G. Environ Health Perspect. 2007 Aug;115(8):1132-9. PMID: 17687438 doi: 10.1289/ehp.9937. Conclusion Vitamin D insufficiency is common over a wide latitude range in Australia. Season appears to be more important than latitude, but both accounted for less than one-fifth of the variation in serum 25(OH)D levels, highlighting the importance of behavioral factors. Current sun exposure guidelines do not seem to fully prevent vitamin D insufficiency, and consideration should be given to their modification or to pursuing other means to achieve vitamin D adequacy.

"UV-related web tools maintained by Ola Engelsen * FastRT - Fast simulations of downward UV doses, indices and irradiances at the Earth's surface: http://nadir.nilu.no/~olaeng/fastrt/fastrt.html. * VitD_quartMED - Calculated Ultraviolet Exposure Levels for a Healthy Vitamin D Status: http://nadir.nilu.no/~olaeng/fastrt/VitD_quartMED.html. * VitD - Duration of Vitamin D Synthesis in Human Skin: http://nadir.nilu.no/~olaeng/fastrt/VitD.html. "

"Retinol-induced Intestinal Tumorigenesis in Min/+ Mice and Importance of Vitamin D Status. Hetland RB, Alexander J, Berg JP, Svendsen C, Paulsen JE. Anticancer Res. 2009 Nov;29(11):4353-60. PMID: 20032378 The effects of life-long dietary exposure, starting in utero, to high retinol, low vitamin D, or high retinol in combination with low vitamin D on intestinal tumorigenesis in Min/+ mice were investigated. In males, high retinol alone significantly increased the number (2.6-fold) and size (1.3-fold) of small intestinal tumours; in females no significant increase in tumour number or size was seen. In both genders, low vitamin D intake alone did not affect intestinal tumorigenesis. In males, intake of the combined high retinol/low vitamin D diet did not further increase the effects caused by high retinol alone. In females, however, the high retinol/low vitamin D-induced increase in tumour number (3.1-fold) and tumour size (1.5-fold) exceeded that of high retinol alone. In conclusion, a high dietary intake of retinol stimulated intestinal tumorigenesis in Min/+ mice. Furthermore, the results indicate a combined effect of high retinol and low vitamin D on tumorigenesis in females"

Athletic performance and vitamin D. Cannell JJ, Hollis BW, Sorenson MB, Taft TN, Anderson JJ. Med Sci Sports Exerc. 2009 May;41(5):1102-10. Review. PMID: 19346976 doi: 10.1249/MSS.0b013e3181930c2b Conclusions: Vitamin D may improve athletic performance in vitamin D-deficient athletes. Peak athletic performance may occur when 25(OH)D levels approach those obtained by natural, full-body, summer sun exposure, which is at least 50 ng·mL-1. Such 25(OH)D levels may also protect the athlete from several acute and chronic medical conditions.

"Last Wednesday night I gave a lecture to my clients on hunter-gatherer diets. The turnout was great and the information was well-received. I had it professionally video-recorded and will probably offer this as a DVD for sale (with the handout included). Watch for it in the future. Part of what I discussed was vitamin D3 supplementation. Since I have been supplementing with 4,000-10,000 Units of D3 per day I have noted enhanced recovery and size response from my training. Apparently, skeletal muscle has both surface receptors and nuclear receptors for D3 that augment calcium flux during contraction (from surface receptors) and have steroid-like effects at the nuclear level WRT protein synthesis. This D3 supplementation is not really "supplementation" but is instead "augmentation" to levels that would be normal if we got normal sun exposure as we did in our evolutionary past. Check out www.vitamindcouncil.org for more information. Also, check out this abstract below for your consideration. Also, check out this article."

Vitamin D supplement in early childhood and risk for Type I (insulin-dependent) diabetes mellitus. The EURODIAB Substudy 2 Study Group. [No authors listed] Diabetologia. 1999 Jan;42(1):51-4. PMID: 10027578 DOI: 10.1007/s001250051112 In conclusion, this large multicentre trial covering many different European settings consistently showed a protective effect of vitamin D supplementation in infancy. The findings indicate that activated vitamin D might contribute to immune modulation and thereby protect or arrest an ongoing immune process initiated in susceptible people by early environmental exposures.