Vitamin D, serum 25(OH)D, LL-37 and polymorphisms in a Canadian First Nation population with endemic tuberculosis
International Journal of Circumpolar Health
6 Northlands Denesuline First Nation, Lac Brochet, MB, Canada Background. Canadian First Nation populations have experienced endemic and epidemic tuberculosis (TB) for decades. Vitamin DÁmediated induction of the host defence peptide LL-37 is known to enhance control of pathogens such as Mycobacterium tuberculosis. Objective. Evaluate associations between serum levels of 25-hydroxy vitamin D (25(OH)D) and LL-37, in adult Dene First Nation participants (N 0 34) and assess correlations with
... elations with single nucleotide polymorphisms (SNPs) in the vitamin D receptor (VDR) and vitamin D binding protein (VDBP). Design. Venous blood was collected from all participants at baseline (winter and summer) and in conjunction with taking vitamin D supplements (1,000 IU/day) (winter and summer). Samples were analysed using ELISA for concentrations of vitamin D and LL-37, and SNPs in the VDR and VDBP regions were genotyped. Results. Circulating levels of 25(OH)D were not altered by vitamin D supplementation, but LL-37 levels were significantly decreased. VDBP and VDR SNPs did not correlate with serum concentrations of 25(OH)D, but LL-37 levels significantly decreased in individuals with VDBP D432E T/G and T/T, and with VDR SNP Bsm1 T/T genotypes. Conclusions. Our findings suggest that vitamin D supplementation may not be beneficial as an intervention to boost innate immune resistance to M. tuberculosis in the Dene population.