Vitamin B12, which is found in animal products, such as meat, shellfish, milk, cheese and eggs, is needed to produce red blood cells and maintain a healthy nervous system. But little is known about the vitamin's affects on skeletal health, specifically among ageing women.
Researchers at the University of California, San Francisco, led by Dr Katie Stone, studied a random, cohort study of 83 women over the age of 64 who participated in the Study of Osteoporotic Fractures.They archived baseline serum samples and measured hip bone mineral density in study subjects during two and six year follow-up examinations.
Results, published in this month's Journal of Clinical Endocrinology and Metabolism , demonstrated that after adjusting for age, weight and clinic site, women with the lowest levels of B12 (below 280 pg/ml) experienced significantly more rapid hip bone loss than women with higher levels of B12 (above 280 pg/ml).
Rapid bone loss is a sign of osteoporosis, a condition that affects one in three women over the age of 50, and designated by the World Health Organisation as the second leading global health care problem after cardiovascular disease. Bone density loss is usually gradual and without noticeable symptoms.
"While deficiencies in vitamin B12 are uncommon among younger women, many older women suffer from vitamin B12 deficiency," said Dr Stone. "Our research shows that the women with the lowest levels of vitamin B-12 are at an increased risk for bone loss in their hips, which could lead to fractures."
"We knew that vitamin B-12 benefited the nervous system, but our findings suggest that it may also benefit bone health," she added.
The authors note that for some elderly women, simple dietary supplements, multivitamins or dietary modification may slow the rates of bone loss, but a larger, randomized trial would be needed to determine whether treatment with supplemental vitamin B12 could reduce rates of bone loss in elderly women.
High calcium and vitamin D levels are also thought to help prevent osteoporosis-related fractures, while research suggests that soy isoflavones may help women with low bone mineral content prevent fractures in postmenopause years. There is also evidence from animal studies that antioxidant supplements, such as vitamin C, could reverse osteoporosis.