Calcium and bone metabolism, including intestinal calcium absorption and bone turnover, are affected by a number of factors, such as hormones [e.g., 1,25(OH)2D3, fibroblast growth factor-23 and prolactin] and pathological conditions (e.g., diabetes mellitus and thalassemia)3,5,13,24–26. The gene discussed is FGF23; the disease is diabetes mellitus.