Vitamin D Receptor gene polymorphism may predict response to vitamin D intake and bone turnover

Background and the purpose of the study: The molecular and functional basis of the VDR polymorphisms is fundamental to appreciate their potential clinical implications. The rationale of this study was to determine the level of serum vitamin D response to vitamin D intake in different genotypes of VDR (FokI) polymorphism and its effect on the bone turnover in postmenopausal women.Methods: The subjects for the study were 312 pre and post-menopausal women aged between 20-75 year randomly selected from the participants of Iranian multicenter osteoporosis study. After an overnight fast, 4ml of peripheral blood was taken and centrifuged to separate serum for measurement of serum parathyroid hormone, 25 hydroxyvitamin D, osteocalcin and cross laps. The FokI polymorphism in exon 2 of the VDR gene was detected by the polymerase chain reaction-restriction fragment length polymorphism.Results and major conclusion: FOKI genotype predicted serum cross laps after adjustment for age, menopausal status, serum vitamin D (p 0.001) but did not find significant prediction regarding serum osteocalcin (p=0.3).Also in this model FOKI genotype predicted serum vitamin D after adjustment for age, menopausal status, calcium and vitamin D intake (p 0.001).VDR gene polymorphism may modifies response to vitamin D intake and predicts bone turnover.