Vitamin D May Lower Alzheimer's Risk

Dementia risks were higher in those who lacked vitamin D in new study

/ Author:  / Reviewed by: Dominique Brooks, M.D Beth Bolt, RPh

(RxWiki News) Alzheimer's disease is often thought of as a part of aging, but it may not have to be. New research suggests a certain vitamin may help prevent the disease.

People with too little vitamin D developed dementia more often than those with enough of it, a new study found.

"Learn ways to lower your risks for Alzheimer's disease."

The study was led by David J. Llewellyn, PhD, of the University of Exeter Medical School in the United Kingdom.

The authors studied 1,658 participants from the Cardiovascular Health Study who did not have dementia when they were 65 years old. Then, they measured the amount of vitamin D in their blood stream for 5.6 years.

At the end of the study period, 171 participants had developed dementia, which reduces a person's ability to remember, reason and plan. Of the 171 people, 102 had developed Alzheimer’s disease, the most common form of dementia. In its late stage, Alzheimer's prevents patients from moving, going the bathroom by themselves, talking or otherwise being independent.

The researchers concluded that, compared to study participants with enough vitamin D in their blood, those who were low in vitamin D increased their risks of developing dementia by 51 percent. Compared to those with normal levels of vitamin D, those who were severely deficient raised their dementia risks by 122 percent.

Also, those with lower levels of vitamin D were almost 70 percent more likely to develop Alzheimer’s than those with enough vitamin D. Those who were severely low in vitamin D were more than 120 percent more likely to develop Alzheimer's than patients with sufficient levels.

The study authors cautioned that their findings required further study to determine whether low vitamin D levels actually caused dementia. The study did not prove a direct link between vitamin D and dementia, Dr. Llewellyn said in a press release.

“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," he said.

Dairy products and fatty fish like salmon, tuna and mackerel are key dietary sources of vitamin D. Exposure to sunlight also causes the body to produce vitamin D.

This study was published online Aug. 6 in Neurology.

Funding for this study came from the National Heart, Lung, and Blood Institute, National Institute of Neurological Disorders and Stroke, National Institute on Aging, Alzheimer’s Association and other donor groups. The study authors did not disclose any conflicts of interest.

Review Date: 
August 5, 2014
Last Updated:
August 7, 2014