Vitamin D is often called the “sunshine vitamin” because our bodies can make it when we are exposed to sunlight. It is well known for keeping our bones strong and healthy.
Many people also take vitamin D supplements to make sure they are getting enough, especially as they get older.
But researchers have been asking another question: could vitamin D also affect how well our brains work?
A study from Rutgers University in the United States has looked closely at this question. The research focused on women between the ages of 50 and 70 who were overweight or obese.
This age group is important because memory and brain function often start to decline during these years, and being overweight can increase health risks. The scientists wanted to see how different amounts of vitamin D supplements might influence memory and reaction time.
The study lasted one year, and the women were divided into three groups. One group took the recommended daily amount of 600 international units (IU) of vitamin D. Another group took 2,000 IU per day, and the third group took 4,000 IU per day. All the women were also encouraged to lose some weight, since weight loss itself can improve health.
When the researchers looked at the results, they found something interesting. The women who took 2,000 IU every day showed better memory and learning skills compared to those who only took the standard amount. This suggests that vitamin D could play a helpful role in keeping the brain sharp in later life.
However, there was also an unexpected finding. While memory improved, reaction times became slower. At 2,000 IU per day, reaction times slowed a little, and at 4,000 IU, the slowing was much more noticeable.
Why does this matter? Reaction time is the speed at which a person responds to something, such as when they need to quickly move out of the way of an obstacle while walking. Slower reaction times in older adults could raise the risk of falling, which is a major health concern.
Falls can cause broken bones and other serious injuries, and they are a leading reason why many older people lose independence. Previous studies have also warned that higher doses of vitamin D, such as 2,000 IU or more per day, might increase the risk of falls.
The Rutgers study supports this idea and shows that while vitamin D might help the brain in some ways, too much could create new problems.
The researchers stress that more work is needed to fully understand how vitamin D affects both memory and reaction time. They also point out that the study only included women, so future research should test whether men respond in the same way.
In addition, scientists still need to confirm whether slower reaction times caused by high vitamin D intake actually lead to more falls and injuries in real life.
This research was published in The Journals of Gerontology: Series A and was led by Dr. Sue Shapses and her team. It adds to a growing body of evidence showing that vitamins, diet, and lifestyle can influence brain health as people age.
Other studies, for example, have found that following a Mediterranean diet, which is rich in fruits, vegetables, fish, and olive oil, may help protect memory. Vitamin B supplements have been linked to lower dementia risk, and diets high in fiber and antioxidants may also protect the brain.
For now, the key message seems to be about balance. Vitamin D is important for both bones and the brain, but taking very high doses might do more harm than good.
As people grow older, it may be best to follow medical advice and aim for safe levels of vitamin D that support memory without slowing down the body’s responses. Finding that balance could help older adults stay both sharp in mind and steady on their feet.
If you care about dementia, please read studies about Common drug for constipation is linked to higher dementia risk and findings of Scientists find link between heartburn drugs and increased dementia risk.
For more about dementia, please read studies about Scientists find a drug related to Viagra may help treat vascular dementia and findings of link between body inflammation and dementia risk.
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