Vitamin D receptor found in human sperm

ObjectivesSeveral animal studies have suggested that vitamin D and the vitamin D receptor (VDR) play a role in male fertility. The mechanism of action in the testis and the interaction with sperm is unknown. The presence of the VDR on sperm has never been demonstrated. The objective of this pilot study was to investigate the presence of the VDR on human sperm.MethodsA prospective study of sperm collected from 10 fertile men, mean age 33.7 ± 2.2 years, was undertaken. Qualitative analysis for VDR was performed by immunohistochemistry using a monoclonal antibody to human VDR. For comparison of the spatial relationship of the receptor, qualitative analysis of the androgen receptor on sperm was performed. Immunoprecipitation and immunoblotting of total sperm protein lysate using VDR antibodies further characterized the VDR.ResultsImmunohistochemistry demonstrated that the VDR was located predominantly on the head/nucleus of the sperm and mid-piece. Immunoblotting confirmed the presence of the VDR with a molecular weight of 50 kDa in all subjects.ConclusionsOur results have demonstrated the presence of the VDR on human sperm for what we believe to be the first time.