Patrick Borel
Aix-Marseille University, France
Title: Genetic variations associated with vitamin D (cholecalciferol) bioavailability
Biography
Biography: Patrick Borel
Abstract
Most people require dietary vitamin D (VD) to achieve the recommended blood level of 25-hydroxycholecalciferol (25OHD). However, blood response to VD supplementation is highly variable among individuals. Our main objective was to assess whether the variability in D3 bioavailability was associated with single nucleotide polymorphisms (SNPs) in candidate genes. 39 healthy adult men were genotyped using whole-genome microarrays. Following an overnight fast, plasma 25OHD status was measured and the subjects then consumed a meal providing 5 mg D3 as a supplement. Plasma chylomicron D3 concentrations were measured over 8 h, and D3 response calculated by determining the postprandial AUC. Partial least squares regression was used to assess the association of SNPs in or near candidate genes (61 genes representing 3791 SNPs) with the postprandial D3 response. The mean postprandial chylomicron D3 concentration peaked at 6 h. The D3 response was very variable among individuals (CV=47%), and it did not correlate with the fasting plasma 25OHD concentration. A significant (P=1.32x10-4) partial least squares regression model, which included 17 SNPs in 13 genes were associated with the variance in the D3 response. There is a high inter-individual variability in D3 bioavailability which is associated with a combination of SNPs.