Scientists from Bonifatius Hospital Lingen have explored how vitamin supplements might affect a person’s risk of developing dementia and mild cognitive impairment.
Dementia is a condition that affects thinking, memory, reasoning, and the ability to carry out everyday activities.
In advanced stages, people may lose independence and experience significant changes in behaviour, emotion, and personality.
Because there is growing evidence that diet and nutrition play an important role in brain function, researchers set out to examine whether taking vitamin supplements could help protect cognitive health as people age.
To do this, they conducted a detailed review of studies published between 2011 and November 2021.
They searched multiple scientific databases and focused on previously published research that investigated the relationship between vitamin supplementation and cognitive performance.
Among the different vitamins studied, folic acid showed the most consistent benefits. Supplementation with folic acid was linked to improved cognitive performance in several studies. When folic acid was combined with vitamin B12, the results were mixed — some studies showed benefits, while others did not find significant improvements.
Thiamine, also known as vitamin B1, showed more promising results. When taken alone, thiamine was found to support cognitive function, and its effects were also positive when combined with folic acid. These findings highlight the potential importance of B-complex vitamins in maintaining brain health.
On the other hand, the evidence for vitamin D was less encouraging. Studies did not consistently show that vitamin D supplements improved cognitive performance or reduced dementia risk. Similarly, low doses of vitamins C and E were not clearly linked to better cognitive outcomes.
However, when vitamin C and high doses of vitamin E were taken separately, there were some positive effects on cognitive performance. Even so, the evidence is currently too limited to make strong recommendations for their use in preventing cognitive decline.
Overall, the researchers concluded that B-complex vitamins — especially folic acid, and possibly thiamine — may help delay or reduce the risk of cognitive decline. In contrast, the evidence supporting vitamins C, D, and E for dementia prevention remains uncertain.
The team emphasised that more large-scale, long-term studies are needed to better understand how vitamin supplements influence brain health over time. Until then, they suggest that maintaining a healthy, balanced diet rich in natural sources of essential nutrients may be the most reliable strategy for supporting cognitive health.
The findings were published in the journal Nutrients by Victoria Gil Martínez and colleagues.
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