Old people with low levels of vitamin D face a high risk of developing dementia, a new study has found.
The study, conducted by researchers at the University of Exeter Medical School, found that vitamin D-deficient old people had a two times higher risk of developing dementia and Alzheimer's disease than other people.
The study is published in the journal Neurology.
For the study, the researchers used data from the Cardiovascular Health Study. A total of 1,658 adults aged 65 years and above took part in the study. Participants were able to walk and were free from dementia and other health problems. All participants were followed for about six years.
The researchers found that participants who were moderately deficient in vitamin D had a 53 percent higher risk of developing dementia risk. For the severely deficient, the risk jumped to a whopping 125 percent.
Similarly, risk of Alzheimer's disease was 69 percent in people with moderate vitamin D deficiency, while those with severe vitamin D deficiency had a 122 percent higher risk of AD.
Dementia is a major health issue. Around 44 million people worldwide have dementia and the number is expected to triple by 2050. About one billion people in the world have low vitamin D levels.
Salmon, tuna, beef liver and egg yolks contain small amounts of vitamin D, according to Office of Dietary Supplements.
"Clinical 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,"said Dr. David Llewellyn at the University of Exeter Medical School.
"We need to be cautious at this early stage and our latest results do not demonstrate that low vitamin D levels cause dementia. That said, our findings are very encouraging, and even if a small number of people could benefit, this would have enormous public health implications given the devastating and costly nature of dementia," Llewellyn said in a news release.
Related research has shown that low levels of vitamin D can lead to depression and even early death risk.