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Vitamin D receptor (VDR) gene polymorphisms and haplotypes, interactions with plasma 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D, and prostate cancer risk. Mikhak B, Hunter DJ, Spiegelman D, Platz EA, Hollis BW, Giovannucci E. Prostate. 2007 Jun 15;67(9):911-23. PMID: 17440943 DOI: 10.1002/pros.20570 RESULTS No association was found between these SNPs or their associated haplotypes and all PC subtypes except that haplotype 2 (A-f-b) with Cdx2 A, Fok1 f, and Bsm1 b alleles and haplotype 3 (A-F-B) with Cdx2 A, Fok1 F and Bsm1 B alleles compared to the most common haplotype (A-F-b), were associated with reduced risk of aggressive PC (high stage or Gleason sum 7; P = 0.02), both with two alleles suspected of being low risk. Carriers of the variant Cdx2 A allele who were deficient in plasma 25-hydroxyvitamin D (15 ng/ml) compared to non-carriers with normal 25-hydroxyvitamin D, had a lower risk of total and poorly differentiated PCs (Gleason sum 7) (P for interaction = 0.02 and 0.04, respectively). Plasma 1,25-dihydroxyvitamin D deficiency (26 pg/ml) was associated with a threefold risk of poorly differentiated PC (P for interaction = 0.01) when comparing carriers of the Cdx2 A allele to non-carriers with normal 1,25-dihydroxyvitamin D. CONCLUSION In this population of men, none of the VDR polymorphisms studied was associated with susceptibility to PC. Carriers of the variant Cdx2 A allele with low plasma 25-hydroxyvitamin D may experience a reduction in risk of total and poorly differentiated prostate cancers compared to non-carriers with adequate 25-hydroxyvitamin D.

Review and meta-analysis on vitamin D receptor polymorphisms and cancer risk. Raimondi S, Johansson H, Maisonneuve P, Gandini S. Carcinogenesis. 2009 Jul;30(7):1170-80. Epub 2009 Apr 29. Review. PMID: 19403841

Vitamin D receptor gene polymorphisms influence susceptibility to type 1 diabetes mellitus in the Taiwanese population. Chang TJ, Lei HH, Yeh JI, Chiu KC, Lee KC, Chen MC, Tai TY, Chuang LM. Clin Endocrinol (Oxf). 2000 May;52(5):575-80. PMID: 10792336 DOI: 10.1046/j.1365-2265.2000.00985.x CONCLUSIONS Vitamin D receptor gene polymorphisms were associated with type 1 diabetes in a Taiwanese population. However, functional studies are needed to establish the role of the vitamin D receptor in the pathogenesis of type 1 diabetes mellitus.

Vitamin D receptor gene polymorphism: association with Crohn's disease susceptibility. Simmons JD, Mullighan C, Welsh KI, Jewell DP. Gut. 2000 Aug;47(2):211-4. PMID: 10896912 doi:10.1136/gut.47.2.211

Association study on two vitamin D receptor gene polymorphisms and vitamin D metabolites in multiple sclerosis. Smolders J, Damoiseaux J, Menheere P, Tervaert JW, Hupperts R. Ann N Y Acad Sci. 2009 Sep;1173:515-20. PMID: 19758194 DOI: 10.1111/j.1749-6632.2009.04656.x Discussion: We found no association of the Apal and Taql VDR gene SNPs with MS or with vitamin D metabolism in our population. Further research should assess the complex interaction between vitamin D, the VDR, and susceptibility to MS.

Li H, Stampfer MJ, Hollis JBW, Mucci LA, Gaziano JM, et al. (2007) A Prospective Study of Plasma Vitamin D Metabolites, Vitamin D Receptor Polymorphisms, and Prostate Cancer. PLoS Med 4(3): e103 doi:10.1371/journal.pmed.0040103

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

Alcohol and genetic polymorphisms: effect on risk of alcohol-related cancer. Druesne-Pecollo N, Tehard B, Mallet Y, Gerber M, Norat T, Hercberg S, Latino-Martel P. Lancet Oncol. 2009 Feb;10(2):173-80. Review. PMID: 19185835 doi:10.1016/S1470-2045(09)70019-

Vitamin D supplementation. Eveleigh B. Can Fam Physician. 2007 Sep;53(9):1435; author reply 1435. PMID: 17872869 My concern regarding vitamin D2 is that it is a synthetic analogue and might interact with the vitamin D receptor differently in various cell systems. It has been reported that vitamin D3 might improve glycemic control.7 Vitamin D2 has been reported to cause worsening of glycemic control in people of East Indian descent.8 Is this because of vitamin D receptor polymorphism, or because of enhanced 24-hydroxylase enzyme activation, or is it due to how vitamin D2 interacts with the receptor? Until this has been sorted out, I feel safest using vitamin D3. There are about 2000 synthetic analogues of vitamin D. The search is on for one that can cross the blood-brain barrier to treat certain types of brain cancers without causing hypercalcemia.9 But then again, what other effects would this compound have? There are still so many unknowns

Vitamin D and breast cancer. Bertone-Johnson ER. Ann Epidemiol. 2009 Jul;19(7):462-7. Epub 2009 Feb 20. Review. PMID: 19230714 Though the relationship between vitamin D and breast cancer remains unclear, a growing body of evidence suggests that vitamin D may modestly reduce risk. A large number of in vitro studies indicate that vitamin D can inhibit cell proliferation and promote apoptosis and cell differentiation in breast tumor tissue. Results from analytic studies of sunlight exposure and dietary intake have been inconsistent but together generally support a modestly protective role of vitamin D, at least in some population subgroups. Studies using blood vitamin D metabolites to assess vitamin D status may be less prone to misclassification than those of diet and sunlight exposure. Overall, the two prospective and four case-control studies of 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D tend to support a protective effect in older women. The relationship between common vitamin D receptor polymorphisms and risk remains unclear. Many questions about this relationship clearly remain, including the utility of assessing vitamin D through diet and sunlight exposure, the relationship between plasma metabolites, and the potential modifying effects of age, menopausal status and tumor characteristics. Given that vitamin D status is modifiable, additional prospective studies are necessary to determine if vitamin D may have important potential for breast cancer prevention.

Ordovas JM. Genetic interactions with diet influence the risk of cardiovascular disease. Am J Clin Nutr. 2006 Feb;83(2):443S-446S. Review. PMID: 16470010 [PubMed - indexed for MEDLINE]

Novel role of the vitamin D receptor in maintaining the integrity of the intestinal mucosal barrier. Kong J, Zhang Z, Musch MW, Ning G, Sun J, Hart J, Bissonnette M, Li YC. Am J Physiol Gastrointest Liver Physiol. 2008 Jan;294(1):G208-16. Epub 2007 Oct 25. PMID: 17962355 These observations suggest that VDR plays a critical role in mucosal barrier homeostasis by preserving the integrity of junction complexes and the healing capacity of the colonic epithelium. Therefore, vitamin D deficiency may compromise the mucosal barrier, leading to increased susceptibility to mucosal damage and increased risk of IBD.

Role of vitamin D in the pathogenesis of type 2 diabetes mellitus. Palomer X, González-Clemente JM, Blanco-Vaca F, Mauricio D. Diabetes Obes Metab. 2008 Mar;10(3):185-97. Review. PMID: 18269634 DOI: 10.1111/j.1463-1326.2007.00710.x Vitamin D deficiency has been shown to alter insulin synthesis and secretion in both humans and animal models. It has been reported that vitamin D deficiency may predispose to glucose intolerance, altered insulin secretion and type 2 diabetes mellitus. Vitamin D replenishment improves glycaemia and insulin secretion in patients with type 2 diabetes with established hypovitaminosis D, thereby suggesting a role for vitamin D in the pathogenesis of type 2 diabetes mellitus.