Low vitamin D can lead to cognitive decline in elderly, study confirms

Vitamin D-deficient seniors may want to look up on how to address this health risk, as a new study shows that they are 30 percent more prone to experience a faster decline in cognitive function, NPR reports.

According to Mirror, a study was conducted by Professor Joshua Miller, chair of the Department of Nutritional Sciences at Rutgers University and his team, who examined 382 participants who were around 75 years old at the time of the study. Additionally, 62 percent of participants were women, 30 percent were African American, 25 percent Hispanic, and 41 percent white.

Most of the participants were already low on vitamin D, as evidenced by the measurement of 25-hydroxyvitamin D in the blood. Results showed that 25 percent of the participants were vitamin D deficient, while 35% of them had levels that were deemed insufficient.

According to Miller, "About 60% or more of the participants were low in vitamin D, either insufficient or outright deficient." He also told Medical Daily that the African American and Hispanic participants had "significantly lower" levels of vitamin D compared to their white counterparts, which may be caused by the skin pigmentation and how it processes sunlight absorption and conversion to vitamin D.

Medical Daily also reports that the researchers used Neuropsychological Assessment Scales to measure the participants' abilities in areas such as episodic memory, semantic memory, visual perception, and executive function.

The study revealed that participants who had dementia at the start of the study had lower levels of vitamin D compared to their counterparts who had on dementia. Additionally, vitamin D deficiency was linked to accelerated decline in episodic memory and executive function.

"There were some people in the study who had low vitamin D who didn't decline at all and some people with adequate vitamin D who declined quickly," Miller explained to the Mirror. "But on average, people with low vitamin D declined two to three times as fast as those with adequate vitamin D."

Miller added: "Some people may have had melanoma (malignant skin cancer) or fear getting it, or they may live in climates where the sun isn't powerful enough, or do work that keeps them out of the sun. That's where supplements come in."

He further recommended: "We always say, in consultation with your doctor we suggest that older adults have their vitamin D status measured. If it's low, in consultation with their doctor, they might consider taking vitamin D supplements."

Chief scientist at Alzheimer's Research UK told the Mirror, "Vitamin D plays an important role in keeping our bodies healthy and there are a number of studies that suggest a link between vitamin D deficiency and memory and thinking difficulties...We need to see more research into this approach to understand the role vitamin D plays in dementia risk."