Vitamin D is best known for helping to keep our bones strong, but a new study from Rutgers University suggests it may also affect how our brains work—especially in older women.
This research looked at how different amounts of vitamin D might influence memory, learning, and reaction time.
We get vitamin D from sunlight, certain foods, and supplements. Many older adults take vitamin D pills to stay healthy. But scientists still don’t know exactly how much vitamin D people need as they get older. In this study, the researchers focused on overweight or obese women between the ages of 50 and 70 to see how vitamin D might affect their brain function.
The study lasted for one year. The women were split into three groups. One group took the standard daily amount of vitamin D—600 international units (IU). Another group took 2,000 IU, and the third group took 4,000 IU each day. All of the women were also encouraged to lose weight, since losing weight can help improve brain health too.
After a year, the women who took 2,000 IU of vitamin D showed better memory and learning abilities than those who took just 600 IU. This finding suggests that taking more than the basic amount of vitamin D might give the brain a little boost in thinking and remembering.
But the study also found something unexpected. The women who took 2,000 IU had slightly slower reaction times, and those who took 4,000 IU were even slower. Reaction time is important for older adults because being able to respond quickly helps prevent falls. Falling can lead to serious injuries like broken bones, so slow reactions can be dangerous.
Previous research has already suggested that taking too much vitamin D—more than 2,000 IU a day—might increase the risk of falling. This new study supports that concern. Even though high doses may help memory, they could also slow down physical responses, which is a problem for aging adults.
The study brings up important questions. For example, will slower reaction times actually lead to more falls? Do men and women respond to vitamin D in the same way? Researchers still need to study these questions to understand what is the safest and most helpful dose for everyone.
While vitamin D is important, it’s only one part of keeping your brain healthy. Eating a healthy diet can help too. The Mediterranean diet, which includes fruits, vegetables, nuts, whole grains, and healthy fats, has been shown to support brain health.
Other studies suggest that B vitamins, fiber-rich foods, and antioxidants found in berries and nuts may also help protect the brain from aging and diseases like dementia.
This study, led by researcher Sue Shapses and published in The Journals of Gerontology: Series A, shows that more vitamin D is not always better. Taking very high doses could help with memory but may also raise the risk of falling due to slower reactions.
If you take vitamin D supplements, it’s smart to talk to your doctor. They can help you decide on the right amount that supports your brain and body health without causing side effects.
If you care about nutrition, please read studies about why vitamin K is so important for older people, and this snack food may harm your heart rhythm.
For more health information, please see recent studies about vitamin that may protect you from type 2 diabetes, and results showing this common chemical in food may harm your blood pressure.
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