Could This Vitamin Support Brain Health In Adults With Poor Sleep? 

With age, changes in sleep and cognition can become more noticeable. Mild cognitive impairment (MCI) is a condition characterized by changes in memory or other thinking abilities that are greater than expected with normal aging (but are not severe enough to interfere substantially with daily life), and it affects a significant portion of older adults. Sleep disturbances are also common among people with MCI, with research suggesting that roughly one-third to nearly half of people1 with MCI experience sleep problems.

But it's also known that poor sleep has been associated with worse cognitive outcomes, while changes in the brain associated with MCI may also contribute to sleep disruption. Researchers are increasingly interested in whether lifestyle factors, including nutrition, could play a role in this relationship.

For this study, researchers wanted to investigate whether daily vitamin D supplement intake was associated with cognitive performance in people with both mild cognitive impairment (MCI) and sleep disturbance. The study included 54 adults with an average age of 67 who had diagnosed or suspected MCI and disturbed sleep. Researchers assessed participants' cognitive function using the Montreal Cognitive Assessment (MoCA) and collected information about their daily vitamin D supplement intake.

They then used statistical analysis to examine the relationship between vitamin D intake and cognitive scores, accounting for factors including age, sex, BMI, vitamin D type, and education level.

After adjusting for age, sex, BMI, vitamin D type, and education, the association between taking 5,000 IU or more of vitamin D daily and MoCA score remained statistically significant. Interestingly, lower doses of vitamin D weren't significantly associated with MoCA scores.

Researchers interpret the finding as preliminary evidence that higher-dose vitamin D supplementation may be associated with better cognition in this specific population.

The study authors say these findings add to previous research investigating the relationship between vitamin D and cognitive function, although that research has produced mixed results. They suggest that higher-dose vitamin D supplementation may be associated with better overall cognitive performance in people with both MCI and sleep disturbance, and call for larger studies to further investigate the relationship.

Vitamin D is a nutrient your body needs for far more than bone health. It's involved in calcium absorption, muscle function, immune function, and other physiological processes, which is one reason maintaining adequate vitamin D status matters throughout adulthood.

And while your body can make vitamin D when your skin is exposed to sunlight, getting enough from sunlight and food alone isn't always easy (or safe). Vitamin D is naturally present in relatively few foods, and factors including season, geographic location, skin pigmentation, age, sunscreen use, and time spent outdoors can all influence how much vitamin D your body produces.

Vitamin D plays a role in far more than bone health, and maintaining adequate levels is an important part of supporting your overall health as you age. While research is still exploring how vitamin D status may relate to sleep and cognition (it looks quite promising), supplementation can be a helpful, efficient way to raise and maintain vitamin D levels when you aren't getting enough.