The Effect of 1,25-Dihydroxyvitamin D3 on Cultured Human Hair Follicle Cells from a Patient with Vitamin D-Dependent Rickets Type II with Alopecia

The study examined the effects of 1, 25-dihydroxyvitamin D3 on cultured human hair follicle cells from a patient with vitamin D-dependent rickets type II (DDR-II) with alopecia. It was found that while normal hair follicle cells showed inhibited clonal growth and stimulated terminal differentiation in the presence of 100 nM 1, 25-dihydroxyvitamin D3, the cells from the patient with DDR-II did not respond to the hormone. This suggested a lack of specific receptors in the patient's cells. The study highlighted a clear difference in cellular response between normal and DDR-II affected cells, which could aid in the rapid diagnosis of DDR-II. Additionally, a new culture method was developed to study hair follicle cells from patients with alopecia, who have a limited number of hair follicles.