Vitamin D Hydroxylation-Deficient Rickets, Type 1a, also known as vitamin d-dependent rickets, type 1a, is related to hypocalcemic vitamin d-dependent rickets and hypoparathyroidism, and has symptoms including muscle weakness, bone pain and difficulty standing. An important gene associated with Vitamin D Hydroxylation-Deficient Rickets, Type 1a is CYP27B1 (Cytochrome P450 Family 27 Subfamily B Member 1), and among its related pathways/superpathways are Infectious disease and Metapathway biotransformation Phase I and II. The drugs Parathyroid hormone and Teriparatide have been mentioned in the context of this disorder. Affiliated tissues include bone and kidney, and related phenotypes are rickets and hypocalcemia