The studies - one from the Netherlands and the other carried out in the United States - show that increased homocysteine levels significantly raise the risk of both hip fracture and other broken bones resulting from osteoporosis.
B vitamins including folic acid have been shown to lower levels of the amino acid homocysteine, reducing its potential damage to the arteries and atherosclerosis. High homocysteine levels in the blood have also been linked to risk of dementia in the elderly.
But until now, the only vitamins related to bone health have been vitamin D and vitamin K. The latest findings, published in the 13 May issue of the New England Journal of Medicine, could offer a new boost to bread and cereal makers fortifying their products with folate and supplement makers targeting the elderly.
The World Health Organisation has defined osteoporosis as the second leading health care problem after cardiovascular disease and its growing incidence and future impact is strongly related to our ageing populations.
In the UK market alone, functional foods to target bone health, such as those fortified with calcium, were worth 88.27 euros in 2002 and this is set to increase by 7.6 per cent yearly to 2007, according to Datamonitor research.
The Dutch study (vol 350:2033-2041), from researchers at the Erasmus Medical Center in Rotterdam, Wageningen University and the Vrije Universiteit Medical Center in Amsterdam, found that in 2406 subjects, aged 55 or older, those with the highest homocysteine levels almost doubled their risk of fracture.
The associations between homocysteine levels and the risk of fracture appeared to be independent of bone mineral density and other potential risk factors for fracture, they said.
Such findings are confirmed by Boston team (pp2042-2049) who found the risk of hip fracture nearly quadrupled in men in the top quartile of homocysteine levels and nearly doubled in the top 25 per cent of women.
"These findings suggest that the homocysteine concentration, which is easily modifiable by means of dietary intervention, is an important risk factor for hip fracture in older persons," concluded the US researchers.