Skin pigmentation related variants in Mexican population and interaction effects on serum 25(OH)D concentration and vitamin D deficiency.

Skin pigmentation is negatively associated with circulating vitamin D (VD) concentration. Therefore, genetic factors involved in skin pigmentation could influence the risk of vitamin D deficiency (VDD). We evaluated the impact genetic variants related to skin pigmentation on VD in Mexican population. This cross-sectional analysis included 848 individuals from the Health Worker Cohort Study (ratio males to females ~ 1:3). Eight genetic variants: rs16891982 (SLC45A2), rs12203592 (IRF4), rs1042602 and rs1126809 (TYR), rs1800404 (OCA2), rs12913832 (HERC2), rs1426654 (SLC24A5), and rs2240751 (MFSD12); involved in skin pigmentation were genotyped. Skin pigmentation was assessed by self-report. Linear and logistic regression were used to assess the association between the variants of interest and VD and VDD, as appropriate. In our study, eight genetic variants were associated with skin pigmentation. A genetic risk score built with the variants rs1426654 and rs224075 was associated with lower VD levels (β = - 1.38, 95% CI - 2.59, - 0.17, p = 0.025). Nevertheless, when examining gene-gene interactions, we observed that rs2240751 × rs12203592 were associated with VD levels (P interaction = 0.021). Whereas rs2240751 × rs12913832 (P interaction = 0.0001) were associated with VDD. Our results suggest that skin pigmentation-related gene variants are associated with lower VD levels in Mexican population. These results underscore the importance of considering genetic interactions when assessing the impact of genetic polymorphisms on VD levels.