Vitamin D Deficiency Linked to Higher Risk of Early-Onset Dementia

New research identifies 15 factors tied to increased risk of early-onset dementia.

By  George Citroner

January 25, 2024

Forgetfulness and confusion, once considered normal signs of aging, are affecting more adults at the peak of their careers.

Rates of early-onset dementia and Alzheimer’s disease among Americans younger than 65 have inexplicably doubled between 2013 and 2017, according to data from Blue Cross Blue Shield (BCBS), a health insurance provider.

Now, new research identifies vitamin D deficiency as one of the 15 adjustable lifestyle factors that appear to drive up a person’s early dementia risk. While the findings also highlight alcohol abuse and isolation, the surprising link between low vitamin D levels and early cognitive decline suggests a simple daily supplement may help the fight against this baffling rise. Approximately 35 percent of adults in the United States are vitamin D deficient.

Largest Study of Its Kind

The average age of someone between 30 and 64 years old living with either young-onset dementia or Alzheimer’s is 49, with women being disproportionately affected compared to men, according to the BCBS data.

The large-scale study, published in JAMA Neurology, identified 15 lifestyle and health risk factors associated with early-onset dementia.

The study analyzed information from more than 356,000 people younger than 65 whose data were in the UK Biobank, a large-scale biomedical database and research initiative in the UK, between 2006 and 2010.

“This is the largest and most robust study of its kind ever conducted,” David Llewellyn of the University of Exeter said in a statement.

Risk Factors for Young-Onset Dementia

“Young-onset dementia has a very serious impact because the people affected usually still have a job, children, and a busy life,” Stevie Hendriks from the Department of Psychiatry and Neuropsychology at Maastricht University in the Netherlands, who was the lead author of the study, said in the statement. “The cause is often assumed to be genetic, but for many people, we don’t actually know exactly what the cause is.”

Major contributing risk factors included alcohol abuse, stroke, and hearing impairment—all previously identified as risks for cognitive decline.

However, the study also identified some additional risk factors associated with early-onset dementia that have not been previously explored in depth, including vitamin D deficiency, high levels of inflammatory C-reactive proteins, specifically in women, orthostatic hypotension (low blood pressure that happens when standing after sitting), and social isolation.

Vitamin D Reduced Dementia Risk by 40 Percent

Previous epidemiological studies have also linked vitamin D deficiency with an increased risk of dementia, Claire Sexton, senior director of scientific programs and outreach at the Alzheimer’s Association, told The Epoch Times.

However, relatively few studies have specifically examined risk factors for young-onset dementia, making Ms. Hendriks and team’s study “a welcome addition to the literature,” Ms. Sexton said.

One relevant study, published in the Alzheimer’s Association’s journal Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring, compared dementia onset between people who took vitamin D supplements and those who did not.

The study included 12,388 Americans without a dementia diagnosis at baseline, with an average age of 71.

The study found that among those who developed dementia within 10 years, about 75 percent were non-supplement takers compared to only 25 percent who took vitamin D supplements. Supplementation provided greater protection for women, though it reduced dementia risk in both sexes.

Interestingly, the study found that vitamin D seemed to offer more benefits if people supplemented it before any signs of cognitive problems.

“Vitamin D effects were significantly greater in females versus males and in normal cognition versus mild cognitive impairment,” the authors wrote.

Overall, the researchers associated vitamin D supplementation with a 40 percent lower incidence of dementia than with no supplementation.

“However, the results of randomized controlled clinical trials of vitamin D interventions on cognitive performance have been mixed,” Ms. Sexton said, noting that further research is needed to confirm the link between vitamin D deficiency and dementia risk.

The Risk Factors We Can Change

Of the risk factors identified in the recent study, several stand out as addressable through lifestyle changes. These include alcohol abuse, diabetes, heart disease, and stroke—with the latter two being linked to high blood pressure, itself a dementia risk factor.

Moderate exercise, smoking cessation, and dietary improvements can mitigate these.

More difficult to tackle is loneliness, termed “social isolation” by the researchers. Participants who visited friends and family less than once a month showed higher young-onset dementia rates compared to those who had more frequent visits.

According to U.S. Surgeon General Vivek Murthy, even before the COVID-19 pandemic, about half of American adults reported experiencing loneliness. He recommends taking steps to reduce feelings of social isolation, such as answering a phone call from a friend, making time to share a meal, and listening to someone without looking at your cellphone.

“Social isolation is linked to depression, but depression did not mediate the association of social isolation with YOD (young-onset dementia) in our analyses, suggesting that both directly contribute to dementia risk,” the study authors wrote.

To help prevent early-onset dementia, experts recommend making lifestyle changes to mitigate key risk factors such as vitamin D deficiency, inflammation, low blood pressure, and social isolation.