Vitamin D 'can cut risk of heart disease and diabetes'

Exposure to sunshine alongside a healthy diet rich in oily fish such as salmon, tuna and mackerel can provide adequate protection, they said.

Researchers reviewed 28 existing studies on almost 100,000 people looking at vitamin D levels among the middle-aged and elderly.

The team, from Warwick Medical School, examined the effect of the vitamin on cardiovascular disease, Type 2 diabetes and metabolic syndrome.

One of the authors, Dr Johanna Parker, who is currently working in a Birmingham GP practice, said: "The research we conducted looked at naturally-occurring vitamin D rather than supplements.

"We recommend people eat a healthy diet with two to three portions of oily fish a week and five portions of fruit and vegetables.

"Most – 90 per cent – of your vitamin D comes from sunshine so we recommend sensible sun exposure in the summer.

"People should expose themselves for 30 minutes twice a week – this means exposing the face and arms with no sunscreen.This would provide the body with adequate vitamin D."