A shortage of vitamin D can lead to Parkinson's disease and mental decline in old age, new research suggests. One 30-year study of 3,000 people revealed a three-fold higher risk of developing Parkinson's in those with low blood levels of vitamin D.
A separate investigation found that low vitamin D intake was associated with a 60 per cent greater chance of suffering seriously impaired mental faculties later in life.
Both studies, published in Archives of Internal Medicine, add to evidence of the vitamin's importance. Vitamin D is mainly generated by the action of sunlight on the skin. As people age their skin becomes less able to produce it.