Calcitriol-Resistant Rickets With Alopecia

Four children from two related families exhibited alopecia and severe rickets that were resistant to treatment due to defective cytoplasmic and nuclear receptors for calcitriol, the active form of vitamin D. Despite the alopecia, scalp biopsies showed a normal number and appearance of hair and hair follicles. The study suggested that calcitriol-resistant rickets should be recognized as an inherited disorder affecting hair growth, and the combination of rickets and alopecia should be considered in diagnosing hair loss.