Selenium for Musculoskeletal Health

This research aims to determine whether selenium supplements improve bone and muscle health in older women at risk of osteoporosis (low bone density or weak bones) and fracture (broken bones). Osteoporosis is a major public health problem. One in two women and one in five men over age 50 will have a fracture. Fractures cause pain, disability and reduce life-expectancy. Women with below-average bone density around the time of the menopause might have previously taken hormone replacement (HRT) to prevent osteoporosis, but HRT is much less used now due to side effects. Therefore there is a need for safe, effective and inexpensive preventative interventions for women at risk of osteoporosis. Selenium is a chemical nutrient present in several human proteins, including anti-oxidants. Anti-oxidants may protect against ageing of tissues, including bone, by mopping up damaging reactive oxygen molecules (sometimes called 'free radicals'). Selenium is present in soil, and so is obtained from many foods. However, soil selenium levels are low in Europe, and dietary intake in the UK is below recommended levels. We previously found that women with higher blood selenium levels have stronger bones, but this doesn't prove that giving selenium will improve bone strength. The investigators propose a randomised controlled trial to compare selenium supplements with a placebo (dummy treatment) in women with below-average bone density. The investigators will give selenium (at two different doses) or placebo to 120 women for six months and use blood and urine tests and bone density scans to see if giving selenium does have any effect on bone. The investigators will also do muscle function tests and measurements of free radical molecules.