Vitamin D Especially Important for Women’s Brain Health

LOS ANGELES — Vitamin D is important for brain health, but this might be particularly true for women but doesn’t appear to have this beneficial effect in men, early research suggested.

The large study showed an association between greater plasma vitamin D levels in females and better memory and larger subcortical brain structures.

“We found that vitamin D for women was correlated with better cognitive outcomes, but we need to do more research to find out what role vitamin D actually plays at a mechanistic level,” study investigator Meghan Reddy, MD, Psychiatry Resident, UCLA Semel Institute for Neuroscience and Human Behavior, Los Angeles, told Medscape Medical News.

The findings were presented here at the American Psychiatric Association (APA) 2025 Annual Meeting.

Protective Effects

This latest study added to the growing body of literature of research on vitamin D and brain health. Previous studies have shown that vitamin D may influence cognition and brain function in older adults, potentially through its anti-inflammatory, antioxidant, and neuroprotective effects. Research also suggested it may promote brain health by increasing neurotrophic factors and aiding in the clearance of amyloid from the brain.

Recent findings published in the American Journal of Clinical Nutrition suggested that vitamin D may also affect biological aging by preserving telomeres — the protective caps at the ends of chromosomes that shorten with age.

Other research has also shown telomere length may help protect against brain diseases, including a study previously reported by Medscape Medical News, which linked longer leukocyte telomere length to a lower risk for stroke, dementia, and late-life depression.

In the current study, Reddy and colleagues used data from the multisite Human Connectome Project to track individuals over time to understand age-related changes in brain structure, function, and connectivity.

They are investigating various biomarkers that might correlate with aging, including hemoglobin, creatine, glycated hemoglobin (for blood glucose levels), high-density lipoprotein, and low-density lipoprotein, in addition to vitamin D.

The idea, said Reddy, is to track cognitive health using biomarkers in addition to brain imaging and cognitive testing.

The study included 1132 individuals, 57% of whom were women and 66% of whom were White. The average age was approximately 62 years, with participants ranging from 36 to 102 years old. 

Participants underwent neuropsychological testing to assess short-term memory and fluid intelligence — the capacity to reason and solve problems, which is closely linked to comprehension and learning. They also provided blood samples and underwent MRI scans. Researchers divided participants into two age groups: those younger than 65 years and those 65 years or older.

The investigators found a significant association between vitamin D levels and memory in women (P = .04). 

Sex Differences

“What’s interesting is that when we looked specifically at memory, higher vitamin D levels were linked to better memory performance — but only in women, not men,” said Reddy, adding that she found this somewhat surprising.

In women, investigators found a significant association between vitamin D levels and the volume of the putamen (P = .05) and pallidum (P = .08), with a near-significant trend for the thalamus.

In contrast, studies show that in men, higher vitamin D levels were associated with smaller volumes of the thalamus, putamen, and pallidum. There were no differences in the impact of vitamin D by age group.

Sex differences in the relationship between vitamin D, cognition, and brain volume warrant further investigation, Reddy said.

She also noted that the study is correlational, examining memory, brain volume, and vitamin D levels at a single timepoint, and therefore it can only offer a hypothesis.

Future studies will include multiple time points to explore these relationships over time. The results did not determine an ideal vitamin D plasma level to promote brain health in women.

Commenting on the research for Medscape Medical News, Badr Ratnakaran, MD, a geriatric psychiatrist in Roanoke, Virginia, and chair of the APA’s Council on Geriatric Psychiatry, said the finding that women may get more brain benefits from vitamin D than men is “key” because dementia is more prevalent among women since they tend to live longer.

Other research has shown vitamin D may help manage depression in older women, which makes some sense as dementia and depression “go hand in hand,” he said.

Ratnakaran recommended that women take a vitamin supplement only if they’re deficient, as too much vitamin D can lead to kidney stones and other adverse side effects.

The investigators and Ratnakaran reported no relevant disclosures.