The GC2 haplotype of the vitamin D binding protein is a risk factor for a low plasma 25-hydroxyvitamin D concentration in a Han Chinese population

Abstract Background The GC haplotype of the vitamin D binding protein (encoded by the GC gene) might be a risk factor to the vitamin D (VD) nutritional status for many populations, while evidences from the Chinese Han population are sparse. We test the association between vitamin D binding protein genotypes and VD status as well as the metabolic parameters of glucose and lipids in a Han Chinese population. Methods In a cross-sectional study conducted at a health examination centre (registered in ClinicalTrials.gov as QLS2013), 2641 adults were included and grouped according to their plasma 25-hydroxyvitamin D (25OHD) concentrations as VD deficient (VDD), insufficient (VDI), or sufficient (VDS). The rs7041 and rs4588 genotypes were analysed with a molecular beacon-based qPCR method using blood samples. Results Plasma 25OHD concentrations were lower in the GC2/2, rs7041T/T, and rs4588A/A genotypes than the GC1f/1s, rs7041G/T, and rs4588C/C genotypes (P 0.05). Conclusions In a Han Chinese population, the GC2 haplotype or more exactly rs4588A is a risk factor for low VD status but is not associated with glucose and lipid metabolic disorders, which are inversely correlated with the circulating 25OHD concentration in males. Trial registration The study was retrospectively registered in January 2018 as NCT03406234 in the ClinicalTrials.gov online system