Fig. 3
Reciprocal interaction between calcium and iron absorption in thalassemia induces bone loss. Decreased calcium absorption in thalassemia is caused by a reduction in 1,25(OH)2D3 levels and also by iron hyperabsorption/overload. Low hepcidin levels in thalassemia can basically enhance intestinal iron absorption, which decreases calcium absorption. Since hepcidin has been found to enhance calcium transport in BKO mice, a reduction in its level or action possibly diminishes calcium absorption. Consequently, bone loss occurs as a result of low blood calcium levels. Moreover, high iron levels can suppress osteoblast (OB) activity, thus compromising bone formation