Here’s one more reason to keep soaking up the sun and holding on to a healthy diet throughout your life: Too little vitamin D in old age may double your risk of developing dementia and Alzheimer’s disease later in life, according to new findings published online in the journal Neurology and reported by Forbes.com.

For the study, researchers looked at health data from 1,658 people, age 65 and older, across the United States, who had not experienced dementia, heart disease and stroke. Scientists measured these folks’ vitamin D levels and then checked back with them to examine their overall health about five years later.

The results? A total of 171 people ended up developing dementia, with 102 of these cases classified as Alzheimer’s (the most common form of this disease). Turns out, patients with moderately low levels of vitamin D were 53 percent more likely to develop dementia and had a 70 percent higher chance of developing Alzheimer’s.

What’s more, those who were severely deficient in vitamin D were 125 percent more likely to develop dementia and had a 120 percent higher chance of developing Alzheimer’s than participants who had normal levels of the nutrient. (Findings didn’t change even when scientists adjusted for environmental factors such as smoking, alcohol use and education.)

“Vitamin D helps to prevent the accumulation of toxic amyloid plaque that is present in Alzheimer’s disease and prevents vascular brain disease,” explained Gayatri Devi, MD, a neurologist at Lenox Hill Hospital in New York City, who helped work on the report.

The next step, Devi said, is for researchers to do more studies to see exactly how a healthy, vitamin D-rich diet, along with genetic and lifestyle factors, can help prevent dementia and Alzheimer’s.

For more information about how vitamin D helps battle health problems (and for tips on where to get this nutrient), click here.