Effect of genetic factors on the response to vitamin D3 supplementation in the VIDARIS randomised controlled trial

•Supplementation is the best way to improve vitamin D status.•Individual responses to supplementation vary and are influenced by genetic factors.•We assessed whether 28 single nucleotide polymorphisms in six genes were linked to the response to supplementation.•Only two single nucleotide polymorphisms in the GC gene were associated with an increase in 25-hydroxyvitamin D concentrations.•This effect disappeared after >2 mo of supplementation.