Colonic transcriptional response to 1α,25(OH)2 vitamin D3 in African- and European-Americans

•Colonic transcriptional response to 1α,25(OH)2D3 differs between African and European Americans independent of serum vitamin D levels.•Two genes, UPP1 and ZSWIM4, showed definitive replication of inter-ethnic transcriptional response differences to vitamin D treatment in ex vivo colon tissue.•A genetic mechanism underlying vitamin D response of ZSWIM4 and HDAC3 was identified and explains inter-ethnic differences in transcriptional responses.