Older adults with low vitamin D levels — and that accounts for most of them — might lose their
memories and thinking abilities faster than those with normal vitamin D levels, researchers
“There is a recent and growing literature on the associations between vitamin D status and risk
of Alzheimer’s disease/dementia, cognitive decline and brain atrophy,” said Dr. Joshua W. Miller of
Miller and a team at University of California-Davis’ Alzheimer’s Disease Center looked at the
association between blood levels of vitamin D and changes in memory and thinking ability in more
than 300 adults over an average of five years.
Participants were an average of 76 years old and included 158 whites, 113 African-Americans and
Past research has shown that fully half of the U.S. population older than 65 has insufficient or
deficient levels of vitamin D, and that non-whites are more likely to have levels that are too low,
the authors said.
Previous studies have also linked low vitamin D levels to higher risk of dementia. Among people
with cognitive impairment, an estimated 70 to 90 percent have insufficient vitamin D, Miller’s team
In the new study, the researchers looked at blood levels of 25-hydroxyvitamin D, the form
generated when the body converts vitamin D made in the skin in response to sunlight and consumed in
foods such as eggs, oily fish and milk.