Vitamin D deficiency is associated with a substantially increased risk of dementia and Alzheimer's disease in older people, according to the first large-scale study of its kind conducted by multiple institutions in the United States and Britain.
The researchers found that participants who were moderately deficient in vitamin D had a 53 per cent increased risk of developing dementia of any kind, and the risk rose to 125 per cent in those who were severely deficient.
Similar results were recorded for Alzheimer's disease.
The study followed 1,658 adults aged 65 or over for six years, to see whether they developed dementia.
The researchers said that trials are now needed to establish whether eating foods such as oily fish or taking vitamin D supplements can delay or even prevent the onset of Alzheimer's disease and dementia.
Dementia is one of the world's most serious health threats. Worldwide, 35.6 million people have dementia - the figure is expected to almost double every 20 years as populations age.
This article was first published on August 10, 2014. Get a copy of The Straits Times or go to straitstimes.com for more stories.