Thursday, October 09, 2003

Vitamin C Reverses Osteoporosis in Mice

Antioxidant supplements, such as vitamin C tablets, could become the new remedy for osteoporosis, say researchers in the UK.

- 2003/10/09

The need for such treatment is growing as trials continue to show that hormone replacement therapy, previously the mainstay of osteoporosis prevention, may have serious side effects. Osteoporosis was recently classified by the World Health Organization as the second leading health care problem after cardiovascular disease. The disease means that bone is lost more rapidly than it is replaced which can lead to a predisposition to fractures. Professor Tim Chambers and his team from St. George's Hospital Medical School at the University of London found that when there is a deficiency in oestrogen there is also a lowering of antioxidants in the bone, reversed by estrogen. They also found that the administering of antioxidants, in this case vitamin C and N-acetyl cysteine, prevented bone loss. "I believe that our results have revealed the mechanism through which estrogen protects bone against osteoporosis. The results have important implications for the treatment of this common and crippling disease. It should in future be possible to prevent osteoporosis in postmenopausal women by giving them antioxidants, or by causing their bones to make more antioxidants,” said Professor Chambers. For the study, published in the recent issue of the Journal of Clinical Investigation, experiments on mice showed that antioxidants, and the enzymes responsible for maintaining them in a reduced state, fell substantially in rodent bone marrow after ovariectomy. Bone loss was however entirely preventable by giving the mice 20mg of vitamin C per day. The researchers cautioned however that women should not increase RDA intake of the vitamin until further investigation confirms the findings. While prevention of osteoporosis has mainly focused on vitamin D and calcium intake, researchers are also investigating the effect of consuming isoflavones on bone density and metabolism in postmenopausal women.

SOURCE: Journal of Clinical Investigation 112:915-923 (2003)