Across 3 studies, all reported neutral small-sized effects of vitamin D on cognitive function. No studies found statistically significant benefits. The evidence base includes systematic reviews and meta-analyses primarily in clinical populations (adults with mild cognitive impairment and stroke survivors), but dose ranges and study durations were not consistently reported. Overall, the aggregate finding shows no clear cognitive benefit from vitamin D supplementation in the populations studied.
Caveats: Evidence base is small (only 3 studies) — conclusions should be considered preliminary. All studies reported neutral findings, and none reached statistical significance. Doses and durations were not consistently reported, limiting the ability to assess dose–response relationships. The studied populations were clinical (MCI, stroke survivors), so findings may not generalize to healthy adults or those with normal cognitive function.
showed limited influence on vitamin D, lipids, or kMCT effects
Mixed results were seen for omega (ω)-3, tea, and plant extracts
Antioxidants, including vitamins C, B2, and D, along with polyphenols such as xanthohumol, fermented papaya, peanuts, and berry extracts, demonstrate the potential to support cognitive function and promote gut health through mechanisms that modulate microbiome diversity and reduce inflammation.