MOST people are needlessly taking Vitamin D supplements and the practice could even be harmful some scientists have claimed.

The nutrient known as the "sunshine vitamin" is made by the skin in response to sunlight or found in a limited range of foods such as oily fish, egg yolk, red meat, liver, fortified breakfast cereals and fat spreads. It helps maintain calcium levels in the body to keep bones, teeth and muscles healthy and a deficiency leads to rickets in children or bone pain and muscle weakness in adults, known as osteomalacia.

Official public health guidelines from the Scottish Government - based on advice from the Scientific Advisory Committee on Nutrition (SACN) - recommended that everyone over the age of one should consume 10 micrograms of vitamin D a day. In winter months, low sunlight levels mean most people would have to consume supplements to achieve that intake.

Previous studies have also indicated that vitamin D could lower blood pressure and that lack of vitamin D may be a direct cause of multiple sclerosis, which more prevalent in Scotland than almost anywhere else in the world.

However, a new study by scientists from Aberdeen University and the University of Auckland in New Zealand said current evidence does not support the use of vitamin D supplements to prevent fractures and falls.

Writing in the BMJ today [tue] they say there is "no consistent evidence" that taking vitamin D supplements improves musculoskeletal health and they had "no important effects on bone density nor any consistent effects on falls, total fracture, or hip fracture". They add that existing trials also rule out a link between vitamin D supplements and significant reductions in heart attacks, strokes and cancer, and stress that low levels of vitamin D might be "a marker of poor health or lifestyle rather than a causal factor" behind illness. Their findings are based on a comprehensive evaluation of published evidence.

In a debate accompanying the main study, Professor Tim Spector, of King's College London, warned that too much vitamin D can damage bones, muscles and cause renal damage. He also pointed to several randomised trials which that found those with high blood concentrations of vitamin D "had an unexpected increased risk of falls and fractures, suggesting that this vitamin can have unexpected toxic effects."

He added: "Although vitamin D treatment still has a role in people with proved deficiency or in high risk groups such as infirm elderly people or at risk infants, the rest of us should avoid being 'treated' for this pseudodisease, save scarce NHS resources, and focus on having a healthy lifestyle, sunshine, and a diversity of real food."

But Louis Levy, head of nutrition science at Public Health England, said SACN recommendations were based on robust research. He said "Getting enough vitamin D is particularly important because poor musculoskeletal health remains in the top 10 causes of disability adjusted life years.

"For many, a supplement will be necessary."