Dr Katherine Tucker and colleagues from Tufts University in the US report that both men and women with vitamin B12 levels lower than 148 pM had lower average bone mineral density, a measure of bone quality frequently used to assess risk of fracture.
These differences were significant for men at most hip sites and for women at the spine, even after further adjustment for protein intake and plasma homocysteine, they report in the January issue of the Journal of Bone and Mineral Research (vol 20, issue 1, pp152-8).
"This is the first large scale study of its kind to show an association between low vitamin B12 and low bone mineral density in men and it confirms other reports of this association in women," said Tucker.
"Our study provides support for a way in which people can actively lower their risk of osteoporosis and help to preserve quality of life."
Osteoporosis is second only to cardiovascular disease in terms of global healthcare burden, according to the World Health Organisation, and currently affects some 200 million people. The number of sufferers is however set to increase steadily with growing numbers of elderly living longer, and obesity adding extra strain on bones.
Tucker and her colleagues measured bone mineral density and vitamin B12 levels in more than 2,500 men and women participating in the Framingham Osteoporosis Study.
Tucker said that dietary B12 may be important for both men and women in maintaining strong bones. She added: "Some individuals, particularly older people, have difficulty absorbing vitamin B12 from foods, however, and inclusion of breakfast cereals fortified with vitamin B12 or use of vitamin B12 supplements offers additional protection." An estimated 40 per cent of women and 13 per cent of men are at high risk of an osteoporotic fracture in their lifetime. When these fractures occur in older individuals, quality of life can decrease, sometimes dramatically.
Osteoporosis is also associated with higher mortality.