Furthermore, PTH directly affects bone mineralization, decreases mineralization in mature cells, and promotes bone turnover, which may lead to osteomalacia.13,31,32 There have been cases reported that primary hyperparathyroidism could masquerade as rickets, especially in childhood or in adolescence.33–35 The possible explanation is that atypical clinical manifestations of FHH may coexist with vitamin D deficiency, and might be further aggravated by elevated PTH levels. Here, PTH is linked to vitamin D deficiency.