Higher Vitamin D Intake Linked to Improved Cognitive Performance in At-Risk Adults

The study involved 54 adults experiencing sleep disturbances and mild cognitive impairments (MCI), conditions often seen in the early stages of dementia. Participants who reported consuming at least 5,000 IU of vitamin D daily performed over 13% better on cognitive assessments than those who did not take vitamin D.

Findings published in Sleep Medicine reveal that individuals taking 5,000 IU or more of vitamin D scored significantly higher on the Montreal Cognitive Assessment (MoCA) compared to those who were not supplemented, even after adjusting for other variables. MoCA is a commonly used test to evaluate memory and cognitive abilities and assess dementia risk. In contrast, lower daily doses of vitamin D did not correlate with enhanced cognitive scores.

The researchers emphasized the critical timing of interventions. MCI represents a transitional phase between normal cognitive aging and dementia. Victoria Pak, the study's senior author, stated, "In older adults experiencing both sleep disturbance and mild cognitive impairment, this may represent a critical window for intervention, when cognitive changes are emerging, but opportunities to support brain health may remain."

Pak, an associate professor at Emory University's Nell Hodgson Woodruff School of Nursing, noted the importance of identifying modifiable factors like vitamin D intake during the early stages of cognitive decline, especially as Alzheimer's disease rates rise.

The study also compared the effects of different forms of vitamin D, finding no significant difference in cognitive performance between those taking vitamin D2 (typically obtained from plants or fungi) and vitamin D3 (produced by the body after sun exposure or sourced from animal-based foods).

Vitamin D is known to be essential for muscle and nerve function, as well as sleep quality, with sleep problems prevalent among Alzheimer's patients. Approximately 50% of those with moderate to severe Alzheimer's report sleep disturbances, indicating a complex relationship between poor sleep and cognitive decline.

Prior research has linked vitamin D deficiency to sleep issues, including insomnia and frequent awakenings. This preliminary study specifically examines how vitamin D intake relates to cognitive performance in individuals with both MCI and sleep disturbances, and it was funded by the National Institute on Aging of the National Institutes of Health, R01AG097853-01 and R61AG080606. Emory co-authors include Sirui Zhou, Paul Sudeshna, Lynn Marie Trotti, and Donald Bliwise.