Changes in circulating 25-hydroxyvitamin D according to vitamin D binding protein genotypes after vitamin D3 or D2supplementation

Abstract

BackgroundIt is not known whether genetic variation in the vitamin D binding protein (DBP) influences 25-hydroxyvitamin D levels [25(OH)D] after vitamin D supplementation. We aimed to investigate the changes of total 25(OH)D, 25(OH)D3 and 25(OH)D2 in a Thai cohort, according to type of vitamin D supplement (vitamin D3 or D2) and DBP genotype, after receiving vitamin D3 or D2 for 3 months.MethodsThirty-nine healthy subjects completed the study. All subjects received 400 IU of either vitamin D3 or D2, plus a calcium supplement, every day for 3 months. Total serum 25(OH)D, 25(OH)D3 and 25(OH)D2 were measured by LC-MS/MS. Individual genotyping of rs4588 in the DBP gene was performed using real-time PCR.ResultsVitamin D3 supplementation of 400 IU/d increased 25(OH)D3 significantly (+16.2 ± 4.2 nmol/L, p <0.001). Vitamin D2 (400 IU/d) caused increased 25(OH)D2 levels (+22.0 ± 2.11 nmol/L, p <0.001), together with a decrease of 25(OH)D3 (−14.2 ± 2.0 nmol/L, p <0.001). At 3 month, subjects in vitamin D3 group tended to have higher total 25(OH)D levels than those in vitamin D2 (67.8 ± 3.9 vs. 61.0 ± 3.0 nmol/L; p = 0.08). Subjects were then classified into two subgroups: homozygous for the DBP rs4588 C allele (CC), and the rest (CA or AA). With D3 supplementation, subjects with CA or AA alleles had significantly less increase in 25(OH)D3 and total 25(OH)D when compared with those with the CC allele. However, no difference was found when the supplement was vitamin D2.ConclusionGenetic variation in DBP (rs4588 SNP) influences responsiveness to vitamin D3 but not vitamin D2.

Impact of a single oral dose of 100,000 IU vitamin D3 on profiles of serum 25(OH)D3 and its metabolites 24,25(OH)2D3, 3-epi-25(OH)D3, and 1,25(OH)2D3 in adults with vitamin D insufficiency

“…Single nucleotide polymorphisms (SNPs) involved in the synthesis (DHCR7 and CYP2R1), binding and transportation (DBP/GC) and degradation (CYP24A1) of vitamin D and its metabolites have been shown to contribute to differences in the vitamin D response to supplementation [15,[24][25][26]. In contrast to findings from other studies [12], the change in 25(OH)D3 concentrations after therapy in our study was not dependent on the age and BMI of the study participants at baseline.…”

Serum magnesium and not vitamin D is associated with better QoL in COPD: A cross-sectional study

“…In addition, we found that women had significantly higher se vitD than men. This study supports that vitD supplementation increases se vitD (24,30,31). Sixty-two percent of participants took vitD supplementation.…”

Assessment of vitamin D status – a changing landscape

“…Nimitphong et al reported a lesser increase in serum 25-OHD after 3 months of 400 IU/day vitamin D3 supplementation in individuals with the GC(rs4588) CA or AA alleles when compared to CC homozygous individuals. However, no such difference was found when the supplement was vitamin D2 [130]. The group also found a significant association between variants in the PTH gene promoter and serum 25-OHD concentrations.…”