Differences in the genes involved in how we metabolize and transport vitamin D in our bodies may determine the amount of vitamin D that circulates in our blood.
Until recently, there was little evidence of the connection between a specific type of genetic variation called single nucleotide polymorphisms (SNPs, or “snips”), vitamin D levels, and health outcomes that aren’t directly related to the bones.
But a recent review has changed that. Researchers from Queen Mary University of London and Blizard Institute in the UK examined 120 genetic association studies on SNPs in 11 vitamin D pathway genes and their relationship with vitamin D levels and 50 non-bone related health outcomes, such as increased risk of diseases like asthma, autoimmune thyroid diseases and tuberculosis.
The researchers discovered that all 120 of the genetic association studies reported a connection between the above factors. Forty-four studies reported 114 findings suggesting that the variations lead to differing metabolite concentrations of vitamin D, meaning genes may be able to affect vitamin D levels in some way. Seventy-six studies reported 105 findings suggesting that the variations affect health outcomes, of which infectious and autoimmune diseases like HIV and psoriasis were the most frequent.
However, there appeared to be limited evidence within the literature to suggest that these variations can predict vitamin D status, nor was there enough evidence to suggest a direct relationship between the variations and specific disease outcomes. Decoding the genetic influences on nutritional status will continue to be relevant.