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Vitamin D deficiency linked to genetic polymorphisms

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vitamin d deficiency genetic differences At least half of adults in developed countries have deficient levels of vitamin D, and low levels of this vitamin have been linked to bone fragility, cancer, heart disease and immune system problems. Variable levels of vitamin D, which is a by-product of a chemical reaction that occurs when UV light hits the skin and can be found in some fatty fish, across populations has largely been thought to be a simple matter of exposure: failure to get enough sun, eat fatty fish or take supplements would result in deficiency.

Previous research has suggested that vitamin D levels were inherited, in part, but a new study of 33,996 people has found three specific genetic variants that seem to correlate with a person’s levels of vitamin D.

Researchers ran a genome-wide association assay of 16,125 people from five centers in the U.S., Canada and Europe and found that three genetic polymorphisms were associated with varying levels of 25-hydroxyvitamin D, a biomarker used to test for levels of the vitamin itself. The researchers, led by Thomas Wang, of the Division of Cardiology in the Department of Medicine at Massachusetts General Hospital, also ran the same tests on another two batches of five cohorts each and found that the results replicated.

"The presence of harmful alleles at the three confirmed loci more than doubled the risk of vitamin D insufficiency," the researchers noted in their study, published online June 9 in The Lancet.

The genes in question (DHCR7/NADSYN1, CYP2R1 and GC) were involved in cholesterol synthesis, hydroxylation and vitamin D transport, respectively.

These findings were somewhat "unexpected," especially that none of the genes were linked to skin pigmentation or any of the major diseases implicated in vitamin D deficiency, Roger Bouillon, of the Clinic and Laboratory of Experimental Medicine and Endocrinology at Katholieke Universiteit Leuven in Belgium, noted in a commentary that appeared in the same issue of The Lancet. The new findings "only partly explain the wide variability of vitamin D status," he concluded.

The authors of the study agreed that the issue requires further study to shed light on the biological basis of the so-called sunshine vitamin. "Whether genetic predisposition modifies response to sun exposure or dietary supplementation warrants further study," the researchers wrote. "These variants might provide useful genetic approaches to investigate the role of vitamin D insufficiency in several chronic diseases."

Image courtesy of iStockphoto/lakovKalinin

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  1. 1. JeffPrystupa 2:50 pm 06/10/2010

    Vitamin D’s importance lies in its relationship to calcium. The problems ascribed to low D levels are actually hypocalcemic as a result of low irradiated vitamin D levels. This explains the high cancer rates in Norway and Sweden. It is more about calcium than vitamin D – but they share an inseparable relationship – D is the carrier for calcium in the same way that insulin transports sugar.

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  2. 2. Johnay 1:30 pm 06/11/2010

    The headline is a bit ambiguous. Until I read the article I thought it was going to be about vitamin D deficiencies somehow causing polymorphisms.

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  3. 3. dhhixson 1:16 am 05/2/2011

    CALCIUM: Calcium is NOT key, and in fact calcium’s "smiley face" (U-shaped curve for damage from inadequacy vs benefit from adequacy vs toxicity from too much calcium from all sources) is quite narrow.

    VITAMIN D: The first time I ever heard about Vitamin D was in 2003, when I had been asked whether or not osteoporosis could be reversed by ONLY adopting a healthier lifestyle. I spent the next 4 months reading over 1K original research articles, and perhaps as many quasi-scientific articles like this one, and came to the conclusion that osteoporosis could be reversed, but getting one’s blood level of 25(OH)D up to at least 38 ng/ml was a key component (along with SLOW progressive resistance exercises and eliminating all colas from one’s diet).

    In fact, I also learned most people (especially older women) are already getting enough calcium from dietary sources, alone, and are actually putting their health at risk by taking calcium supplements. Since 2003, countless original research articles have been published showing calcium intakes > 500 mg at any one time, or > 1400 mg per day, increase the risks of CVD and reproductive cancers (eg: prostate & breast cancer).

    In contrast, since 2003, we have learned that Vitamin D (not actually a vitamin at all, but a prohormone) regulates perhaps as many as 3000 human genes. We have also learned, without vitamin D, the body cannot use calcium, and instead gets rid of excess dietary calcium as bone spurs, kidney stones, gallstone, atherosclerotic plaque, & etc. We have also learned Vitamin D is a major regulator of our immune systems, protecting us from everything from the common cold, to the bubonic plague. In addition, we have learned Vitamin D deficiency may contribute to the development of many types of cancer (especially colon, prostate and breast cancer), atherosclerosis and Alzheimer’s Disease, just to name a few major life-shortening conditions.
    I recommend checking out:(1); (2)


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  4. 4. dhhixson 1:44 am 05/2/2011

    The term "vitamin D polymorphism" used here applies, I believe, to the vitamin D receptor. We have know that at least 25% of the human population has a mutated vitamin D receptor for over a decade now.

    Like testosterone, estrogen, progesterone, aldosterone, cortisol & the thyroid hormones, vitamin D (once converted in your body to a hormone) exerts its effects by binding to a hormone receptor (the vitamin D receptor/ VDR). If one has a mutated (less effective in terms of getting the job done) VDR, a vitamin D deficiency results in a higher risk of MANY diseases.

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