Wendy Wolfson
RedwoodAge.com

Lowered levels of vitamin D may impair memory, according to a study of middle-aged men.

This large study at the University of Manchester was designed to clarify the relationship of Vitamin D to brain function. It included 3,100 men between the ages of 40 and 79 in eight European cities and was published in the journal Neurology, Neurosurgery and Psychiatry.

Milk and other foods may help your memory. (KathyKSUS Photo)

Researchers checked the men's blood, and then tested them for visual memory, scanning and processing. Men who had high blood levels of vitamin D performed the best on the tests. Those with low levels had poorer cognitive scores.

Vitamin D is produced by the body in response to exposure to sunlight and by consuming such foods as oily fish or fortified milk. It helps keep bones strong by helping cells absorb calcium.

While this study was large enough to show significant results, there still are many factors that can skew the results.  So the researchers controlled for education, smoking, alcohol use, exercise, body mass index, depression symptoms, the time of year, and location, as the time of year and location could influence the amount of sunlight a person gets.

The study only checked people at one point rather than following them over time to know if their scores changed with different levels of vitamin D in their blood.

"We only studied men in this project," wrote Frederick CW Wu, Professor of Medicine and Endocrinology at the University of Manchester and principal investigator on the study, in an email response. "We have no a priori reason to think that Vit D’s action per se is gender-specific although any interaction with sex hormone will clearly be different.

"The component of cognitive function is mainly processing speed, visual scanning/memory assessed by digit symbol substitution," he said.

But Why?
The researchers still do not know exactly how vitamin D influences mental fitness.

They also considered the possibility that the effects seen could be caused by other factors; low levels of vitamin D could be a marker for another condition that could lead to deteriorating brain function, such as cardiovascular disease or diabetes. Or hormone and calcium levels could influence results.

The researchers recommended additional studies to determine if taking vitamin D supplements could halt or reverse age related memory decline.