Genetic, sociodemographic and lifestyle factors associated with serum 25-hydroxyvitamin D concentrations in Brazilian adults: the Pro-Saude Study

This study aims to investigate factors associated with serum 25-hydroxyvitamin D [25(OH)D] concentration in Brazilian adults considering sociodemographic and lifestyle factors, as well as vitamin D-related single nucleotide polymorphisms (SNPs). This is a cross-sectional study (n = 491; 34-7; 251 women), nested within a prospective cohort (Pro-Satide Study). Associations between serum 25(OH)D and sociodemographic characteristics, diet, use of supplement, physical activity, season of blood collection, body fat, skin type, sun exposure index, and SNPs CYP2R1-rs10741657 and GC-rs2282679 were explored by multiple linear regression. The prevalence of serum 25(OH)D c 50nmol/L, was 55%. Serum 25(OH)D was lower among women (beta= -4.38; 95%CI: -8.02; -0.74), those with higher visceral fat (beta= -4.02; 95%CI: -5.92; -212), and those with AC and CC genotypes for GC-rs2282679 (beta= -6.84; 95%CI: 10.09; -3.59; beta= -1063; 95%CI: -17.52; -3.74, respectively). Factors directly associated with serum 25(OH)D included summer (beta= 20.14. 95%CI: 1438; 25.90), intermediate skin type (beta = 6.16; 95%CI: 2.52. 9.80), higher sun exposure (beta = 0.49; 95%CI: 0.22; a 75), vitamin D intake (beta = 0.48; 95%CI: 0.03; (193), and physical activity (beta= 465; 95%CI: 1.54; 7.76). Besides physical activity, diet, and sun exposure, non-modifiable factors, such as GC genotypes must be considered when evaluating vitamin D insufficiency in mixed-race populations. Moreover, high visceral fat in association with poorer vitamin D status deserve attention given that both conditions are unfavorably related with chronic and acute health outcomes.