Vitamin D deficiency could lead to mental decline and Parkinson's disease in old age, recent study results have shown.
Those with low levels of vitamin D in their blood are three times more likely to develop Parkinson's than those with healthy levels, one 30-year research conducted on 3,000 people found.
Another examination revealed that a lack of vitamin D could lead to a 60% higher risk of serious damage to mental faculties later in life.
The skin generates vitamin D in the presence of sunlight, but this process weakens as people grow older.
Vitamin D aids in building strong bones, and also protects against diabetes, cancers and heart ailments.
The first study on Parkinson's was conducted in Finland, involving 3,173 men and women between the ages of 50 to 79. They did not have the disease at the beginning of the research.
Fifty of the participants developed the disease over the 29-year investigation period, through which it was found that low levels of vitamin D could be associated with a three-fold risk to Parkinson's.
US, British and Italian scientists conducted the second inquiry, which analysed the mental performance of 850 people aged 65 or more. It found that over a six-year period, the group that lacked vitamin D severely were 60% more likely to be affected by significant mental decline compared with those who had healthy levels of the nutrient.
The studies were published in the journal Archives of Internal Medicine.