Femurs From Rats Fed Diets Deficient in Copper or Iron Have Decreased Mechanical Strength and Altered Mineral Composition Denis M. Medeiros, 1 * Jasminka Ilich, 2 John Ireton, 1 Velimir Matkovic, 2 Laura Shiry, 1 and Robert Wildman 3 1 Department of Human Nutrition and Food Management, The Ohio State University, Columbus, Ohio 2 Bone and Mineral Laboratory, Department of Physical Medicine and Rehabilitation, College of Medicine, The Ohio State University, Columbus, Ohio 3 Department of Nutrition, The University of Delaware, Wilmington, Delaware A study was conducted to evaluate the influence of copper and iron deficiencies upon femur mineral content and biomechanical properties. Radiogrametry and single photon absorpti- ometry 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. Key words: femur; trace elements; biomechanical strength; iron-deficiency; copper-deficiency INTRODUCTION Nutrient influence upon bone formation, structure, and composition has received much attention; osteoporosis and the role calcium being the most notable. However, deficiency of other minerals need to be considered as well, especially during growing periods and formation of peak bone mass. Copper and iron are known to influence collagen maturation and hence could alter bone composition and structure. Lysyl oxidase is a copper-containing enzyme that catalyzes the crosslinking of the epsilon amino groups of lysine and hydroxyproline *Correspondence to: D. Medeiros, Ohio State University, 1787 Neil Avenue, Columbus, OH 43210–1295 Received 5 May 1997; Accepted 5 December 1997 The Journal of Trace Elements in Experimental Medicine 10:197–203 (1997) © 1997 Wiley-Liss, Inc. PROD #318