Background Vitamin D metabolism and obesity have been linked by several studies, however
the reason for this association is unclear. Our objective was to investigate potential
correlations between genetic variants in key enzymes of vitamin D metabolism and the
body mass index on a representative and random sample of Hungarian adults. Methods
Altogether 462 severely vitamin D deficient individuals were studied at the end of
winter in order to decrease environmental and maximize any relevant genetic effect.
Furthermore, participants with lifestyle factors known to affect vitamin D homeostasis
were also excluded. We selected 23 target SNPs in five genes that encode key proteins
of vitamin D metabolism (NADSYN1, GC, CYP24A1, CYP2R1, VDR). Results Variants in 2
genetic polymorphisms; rs2853564 (VDR) and rs11023374 (CYP2R1) showed a significant
association with participants' BMI. These associations survived further adjustment
for total-, free-, or bioactive-25(OH) vitamin D levels, although the variance explained
by these 2 SNPS in BMI heterogeneity was only 3.2%. Conclusion Our results show two
novel examples of the relationship between genetics of vitamin D and BMI, highlighting
the potential role of vitamin D hormone in the physiology of obesity.
