Studies

Explore research connecting ingredients and health goals.

24 ingredient–goal connections

GoalReported findings
SupportiveMixedNo effectAdverseUnclassified

Brain HealthandVitamin D

94published studies

SupportiveNot rated

The available research consistently raises concern about low Vitamin D status, which is often linked with poorer cognitive performance or later decline. Some genetic analyses also support a possible role for deficiency in dementia risk. However, observational links do not establish that taking supplements prevents dementia: illness, diet and behavior can themselves influence vitamin D levels.

Supplementation findings are mixed. Some recent pooled research and trials in older adults report improvements in overall cognition or selected mental abilities. In contrast, several controlled trials show no benefit, including research in generally healthy older adults and people with mild to moderate deficiency and early cognitive impairment. Increasing blood vitamin D levels has not consistently translated into better thinking or daily function.

Research concerning stroke, multiple sclerosis or fetal brain development addresses specific settings and often measures associations rather than treatment effects. It cannot establish broad brain protection from routine supplementation. Overall, low status may be relevant to brain health, but neither a dependable cognitive boost nor dementia prevention through extra vitamin D is established.

94 linked studies · 29 sampled for detail · Sep 27, 2026

Study types

  • Cohort study35
  • Cross-sectional study14
  • Randomized trial13
  • Meta-analysis11
  • Systematic review9
  • Narrative review6
  • Guideline / consensus2
  • Clinical trial1
  • Observational study1
  • Protocol1
  • Single-arm trial1

Published by year

  • 1Earlier
  • 02010
  • 02011
  • 62012
  • 22013
  • 32014
  • 82015
  • 42016
  • 72017
  • 52018
  • 72019
  • 32020
  • 62021
  • 72022
  • 52023
  • 52024
  • 122025
  • 132026

Findings over time

Numbers above bars show study counts. Earlier groups years before 2010.

202613 studies

  • Supportive7
  • Mixed2
  • No effect1
  • Adverse3
  • Unclassified0

Population over time

Reported participants by publication year. Select a year to see the total and reporting coverage.

— Participant count not reported. Earlier groups years before 2010.

202612,470 reported participants

Counts reported by 10 of 13 studies. 3 without a reported count.

Totals sum reported counts across studies and reviews; participants may overlap between sources.

Explore this goal

Showing 5 top-ranked studies for Vitamin D and Brain Health.

Top studies

Vitamin D · Brain HealthHighest ranked first
  1. Vitamin D and brain health: an observational and Mendelian randomization study.
    2022Cohort study427,690 participants

    The American journal of clinical nutrition

    Finding In a large prospective UK Biobank analysis, vitamin D deficiency was associated with higher risks of dementia and stroke, especially below 25 nmol/L, though this association is not by itself proof of supplementation benefit.

    SupportiveView source for Vitamin D and brain health: an observational and Mendelian randomization study. (opens in a new tab)
  2. The association between vitamin D and cognition: a systematic review.
    2014Systematic review28 studies reviewed

    Ageing research reviews

    Finding Most cross-sectional studies linked lower vitamin D with worse cognition or more dementia, but 28% found no association, so findings were not uniform.

    SupportiveView source for The association between vitamin D and cognition: a systematic review. (opens in a new tab)
  3. Vitamin D Status and Rates of Cognitive Decline in a Multiethnic Cohort of Older Adults.
    2016Cohort study382 participants

    JAMA neurology

    Finding Mean vitamin D levels were lower in participants with dementia than in those with mild cognitive impairment or normal cognition (P = .006).

    SupportiveView source for Vitamin D Status and Rates of Cognitive Decline in a Multiethnic Cohort of Older Adults. (opens in a new tab)
  4. Vitamin D insufficiency and cognitive impairment in Asians: a multi-ethnic population-based study and meta-analysis.
    2017Meta-analysis2,273 participants7 studies reviewed

    Journal of internal medicine

    Finding Participants with 25OHD above 20 ng/mL had higher mental-test scores and lower observed cognitive-impairment prevalence than participants with lower levels.

    SupportiveView source for Vitamin D insufficiency and cognitive impairment in Asians: a multi-ethnic population-based study and meta-analysis. (opens in a new tab)
  5. Vitamin D status predicts new brain magnetic resonance imaging activity in multiple sclerosis.
    2012Cohort study469 participants

    Annals of neurology

    Finding Higher vitamin D status was associated with lower risks of new MRI lesions.

    SupportiveView source for Vitamin D status predicts new brain magnetic resonance imaging activity in multiple sclerosis. (opens in a new tab)

Counts reflect published studies in our database, not the strength of a benefit. A study may appear in more than one connection.