Femurs from rats fed diets deficient in copper or iron have decreased mechanical strength and altered mineral composition

A study was conducted to evaluate the influence of copper and iron deficiencies upon femur mineral content and biomechanical properties. Radiogrametry and single photon absorptiometry were used to evaluate femur bone mass. Long-Evans male rats were fed purified diets either adequate or deficient in the selected element from weanling until 9 weeks of age. Results demonstrate that in rats fed both the copper and iron restricted diets, the breaking strength was significantly decreased in both femurs. Lower levels of iron and copper were observed in the livers of the respected trace element restricted groups, and femur iron and copper were depressed in both of these groups as well. Femur Cu:Zn was decreased in the copper deficient group and femur zinc levels were elevated in the iron deficient group. Copper and iron restricted rats had smaller cortical and, larger medullary area in a portion of the femur, 1/4 from the distal end, as determined by radiogrametry, but there were no differences at the mid point or proximal portions of the femurs. The influence of iron restriction upon the decreased bone biomechanical strength is a novel finding and deserves further attention, in that iron deficiency anemia is a prevalent public health problem. J. Trace Elem. Exp. Med. 10:197–203, 1997. © 1997 Wiley-Liss, Inc.