Magnesium Deficiency Linked to Osteoporosis

TEL AVIV, Israel & LUEBECK, Germany--Prolonged magnesium deficiency leads to osteoporosis in rats, according to a recent study published in the Journal of the American College of Nutrition, (23, 6:704S-711S, 2004) (www.jacn.org).

Supplemental magnesium (Mg)--used as the only treatment in postmenopausal osteoporosis--has been shown to cause a significant increase of bone density (BD) so the scientists wanted to test its preventive role in the degenerative disease.

Sprague-Dawley female rats fed a Mg-adequate diet (2,000 ppm--[group A]) daily were compared with rats fed a Mg-deficient diet (200 ppm Mg--[group B]) over a period of one year. Urine samples were collected every three months and blood samples at end of the trial. After sacrifice, the rats vertebrae (L3L5) and the femoral regions were examined for BD and the bones' mineral contents estimated.

The mean BD of the L3L5 vertebral bone was significantly higher in group A than in the Mg-deficient group B. The BD of the femoral region was also significantly higher in group A. The stiffness of the femur, as determined by resistance to bending, was slightly greater in group A than in group B, but after correction to diminish the influence of the difference in bone dimensions in the two groups, the stiffness (i.e. loss of elasticity) in group B became significantly greater than that in group A. The force needed to break the bone (F-max) was significantly higher in group A than in group B and remained so after correction, although no longer significantly. In Group B, the diminution of the trabecular bone volume, in relation to tissue volume and the increase in the degree of trabecular interconnection, indicated osteoporosis. In addition, the researchers noted focal osteoporosis of the metaphyseal spongy bone was seen on microscopy.

The scientists concluded experimentally induced prolonged Mg deficiency causes osteoporosis in rats.