Severe Iron Deficiency Decreases Both Bone Formation and Bone Resorption in Rats

The purpose of this study was to clarify the manner in which dietary iron deficiency decreased bone mineral density (BMD) in rats. Eighteen 3-wk-old male Wistar rats were divided into 3 groups of 6 rats each. The rats in 2 of the 3 groups had free access to a control diet (C group) or an iron-deficient diet (ID group) for 4 wk. The rats in the third group (PF group) were pairfed the control diet to the mean intake of the I D group. Compared with the C and PF groups, hematocrit and hemoglobin concentrations were significantly reduced and bone mine raI content and BMD of the femur were significantly lower in the I D group. Bone histomorphometric parameters showed that the bone formation rate and osteoclast surface in the lumbar vertebra were significantly reduced in the ID group compared with the C and PF groups. Furthermore, dietary iron deficiency decreased serum 1,25-dihydroxycholecalciferol, insulin-like growth factord, and osteocalcin concentrations and urinary excretion of deoxypyriclinoline. These results suggest that severe iron deficiency decreases not only bone formation but also bone resorption. J. Nutr. 139: 238-243, 2009.