Osteoporosis is estimated to affect about 75m people in Europe, the USA and Japan. According to the International Osteoporosis Foundation, the total direct cost of osteoporotic fractures is €31.7bn in Europe, and 17.5bn in the US (2002 figure). The total annual cost of osteoporosis in the UK alone is over £1.7bn (€2.5bn), equivalent to £5m (€7.3m) each day.
The most widely used supplements for the prevention of the disease and to help strengthen bones after diagnosis are calcium, which is well-known building-block of strong ones, and vitamin D, which has been shown to boost calcium absorption.
There is also a growing body of science linking vitamin K, considerably less well-known than vitamins A to E, to benefiting bone health as it influences the secondary modification of osteocalcin, a protein needed to bind calcium to the bone matrix.
The new University of Ulster-funded study is aiming to determine if post-menopausal women with a particular genetic make-up can benefit from B-vitamin supplementation to lower homocysteine levels and, therefore, reduce the risk of osteoporosis.
"Individuals who have a poor dietary intake of B-vitamins tend to have high homocysteine levels. In addition, some people have a genetic make-up that causes them to have a higher homocysteine level. Such people may have a greater risk of developing osteoporosis," said Professor Helene McNulty, from the Northern Ireland Centre for Food and Health (NICHE).
"Studies have found that when B-vitamin intake is improved, homocysteine levels are lowered and this offers the possibility of a novel way to reduce osteoporosis," she said.
PhD student Claire Whittle, working under the supervision of Professor McNulty, told NutraIngredients.com that she will screen about 1,000 women in order to find 100 with a specific genetic make-up - the c677T polymorphism in the methylenetetrahydrofolate reductase (MTHFR) gene, which affects folate metabolism and is associated with increased homocysteine levels.
High levels of the amino acid homocysteine (hyperhomocysteinemia) are most commonly used as a marker for heart disease and thought to be a risk factor for atherosclerotic disease, which contributes to heart attacks higher risk of heart disease and strokes. Additionally, high levels of the amino acid have been linked to increased cognitive decline. Indeed, the Framingham study reported that people with homocysteine levels above 14 micromoles per litre of serum had twice the risk of dementia.
A growing body of science is also linking high homocysteine levels to an increased risk of osteoporosis, with studies reporting high levels significantly raise the risk of both hip fracture and other broken bones resulting from osteoporosis.
The project will divide the women into four supplementation groups - riboflavin plus folic acid, riboflavin plus placebo, folic acid plus placebo, and placebo plus placebo - for 24 weeks. The doses are equivalent to the recommended daily intakes for the vitamin (2 milligrams for riboflavin and 200 micrograms for folic acid).
Those women deemed suitable will be given a free DEXA bone scan which is the most accurate way of assessing bone health. Whittle said the first results are expected in 2008.