Association Between Bat Vitamin D Receptor 3′ Haplotypes and Vitamin D Levels at Baseline and a Lower Response After Increased Vitamin D Supplementation and Exposure to Sunlight

Abstract

Abstract. Objective: The aim of this study was to evaluate the relationship between vitamin D levels at baseline and after 12 weeks of supplementation/exposure to sunlight and VDR genotypes (BsmI, TaqI and ApaI) and haplotypes in a homogeneous population of postmenopausal women. Methods: We made a prospective study in which 151 women were randomized to two groups: One with 1000 mg of calcium and 800 IU vitamin D supplementation (102 women) and a placebo group with neither calcium or vitamin D supplementation (49 women). The follow-up was from May to September 2012.Vitamin D was determined by chemiluminescent immunoassay. Genotypes were determined using the Sequenomi Plexplatform and haplotypes using PHASE software. Results: Baseline (25 ± 10 ng/ml vs.23 ± 9 ng/ml, p > 0.05) and 12-week (32 ± 8 ng/ml vs.29 ± 10 ng/ml, p > 0.05) vitamin D levels were similar between the two groups. The genetic study was made in the total population. There were no differences in baseline and final levels of vitamin D in terms of genotypes and haplotypes, except for the Bat haplotype, whose baseline values were lower (25OHD: 21 ± 10 ng/ml vs. 21 ± 10 ng/ml, p = 0.038). The rate of nonresponders in this group was 15 % (p = 0.001), compared with 9 %, 2 % and 3 % in the other groups. Conclusions: The Bat haplotype was associated with lower baseline levels of vitamin D and a worse response to supplementation and, therefore, may be a risk factor for vitamin D deficiency.

Vitamin D Receptor (VDR) Gene Polymorphisms Modify the Response to Vitamin D Supplementation: A Systematic Review and Meta-Analysis

“…Baseline and post-supplementation serum vitamin D levels according to the BsmI, TaqI, ApaI and FokI polymorphisms in the VDR gene are summarized in Table 2. In the case of BsmI polymorphism, two studies associated the variant genotype with better response to vitamin D supplementation [27,30], two studies with worse response [20,32] and two studies did not show statistically significant association [28,29]. Five studies statistically associated the variant genotype of TaqI polymorphism with response to vitamin D supplementation [27][28][29][30]32].…”

“…Of these, 20 articles were excluded because they did not contain the necessary information to carry out the meta-analysis (Supplementary Material Table S2). Therefore, eight studies that fulfilled the inclusion criteria were finally included in the meta-analysis [20,[27][28][29][30][31][32][33]. The response to vitamin D supplementation according to the BsmI polymorphism in the VDR gene was analysed in six studies [20,[27][28][29][30]32].…”

“…Therefore, eight studies that fulfilled the inclusion criteria were finally included in the meta-analysis [20,[27][28][29][30][31][32][33]. The response to vitamin D supplementation according to the BsmI polymorphism in the VDR gene was analysed in six studies [20,[27][28][29][30]32]. Five studies analysed the vitamin D response according to the genotypic distribution of the TaqI genetic variant [27][28][29][30]32].…”

“…The response to vitamin D supplementation according to the BsmI polymorphism in the VDR gene was analysed in six studies [20,[27][28][29][30]32]. Five studies analysed the vitamin D response according to the genotypic distribution of the TaqI genetic variant [27][28][29][30]32]. The influence of the ApaI polymorphism was studied in four articles [27,29,30,32].…”

“…Five studies analysed the vitamin D response according to the genotypic distribution of the TaqI genetic variant [27][28][29][30]32]. The influence of the ApaI polymorphism was studied in four articles [27,29,30,32]. Finally, the influence of the FokI polymorphism in the response to vitamin D supplementation was analysed in five studies [27,[29][30][31]33].…”