Studies

Explore research connecting ingredients and health goals.

28 ingredient–goal connections

GoalReported findings
SupportiveMixedNo effectAdverseUnclassified

Cognitive SupportandVitamin D

118published studies

Supportive

Low Vitamin D status is associated with poorer cognitive performance or greater decline in many observational studies, especially in older adults. Other studies find no independent association after accounting for health and lifestyle factors. These findings cannot determine whether low Vitamin D contributes to cognitive problems or accompanies other conditions linked to them.

Controlled supplementation research is mixed. Some trials in people with mild cognitive impairment or Alzheimer’s disease report improvements, and fortified-food research in children suggests a possible benefit. However, substantial adult trial evidence shows no clear improvement in cognition, including research in community-dwelling older adults and people with low Vitamin D. Raising blood levels alone therefore does not guarantee better thinking.

Dementia prevention is also unproven. Favorable associations among supplement users coexist with unfavorable observational findings, while controlled research in largely Vitamin D-sufficient older adults did not show reduced dementia incidence. The available evidence leaves potential benefits in selected groups open, but does not support assuming that additional Vitamin D improves cognition when nutritional needs are already met.

118 linked studies · 32 sampled for detail · Sep 27, 2026

Study types

  • Cohort study44
  • Cross-sectional study27
  • Narrative review13
  • Randomized trial12
  • Meta-analysis8
  • Systematic review5
  • Single-arm trial3
  • Non-randomized trial2
  • Observational study2
  • Guideline / consensus1
  • Other1

Published by year

  • 2Earlier
  • 22010
  • 32011
  • 32012
  • 12013
  • 22014
  • 62015
  • 72016
  • 62017
  • 62018
  • 82019
  • 72020
  • 92021
  • 62022
  • 132023
  • 82024
  • 132025
  • 162026

Findings over time

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

202616 studies

  • Supportive6
  • Mixed1
  • No effect2
  • Adverse7
  • 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.

2026333,952 reported participants

Counts reported by 13 of 16 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 Cognitive Support.

Top studies

Vitamin D · Cognitive SupportHighest ranked first
  1. The impact of vitamin D food fortification and health outcomes in children: a systematic review and meta-regression.
    2021Meta-analysis20 studies reviewed

    Systematic reviews

    Finding Fortification increased 25(OH)D concentration, with the pooled estimate adjusted for baseline concentration and country latitude.

    SupportiveView source for The impact of vitamin D food fortification and health outcomes in children: a systematic review and meta-regression. (opens in a new tab)
  2. Vitamin D Supplementation Improves Cognitive Function Through Reducing Oxidative Stress Regulated by Telomere Length in Older Adults with Mild Cognitive Impairment: A 12-Month Randomized Controlled Trial.
    2021Randomized trial183 participants

    Journal of Alzheimer's disease : JAD

    Finding Compared with placebo, vitamin D substantially improved multiple cognitive scores, including FSIQ, information, digit span, vocabulary, block design and picture arrangement.

    SupportiveView source for Vitamin D Supplementation Improves Cognitive Function Through Reducing Oxidative Stress Regulated by Telomere Length in Older Adults with Mild Cognitive Impairment: A 12-Month Randomized Controlled Trial. (opens in a new tab)
  3. Effects of vitamin D supplementation on cognitive function and blood Aβ-related biomarkers in older adults with Alzheimer's disease: a randomised, double-blind, placebo-controlled trial.
    2020Randomized trial210 participants

    Journal of neurology, neurosurgery, and psychiatry

    Finding Compared with control, the intervention group improved several listed amyloid-related biomarkers and cognitive test scores in repeated-measures analysis.

    SupportiveView source for Effects of vitamin D supplementation on cognitive function and blood Aβ-related biomarkers in older adults with Alzheimer's disease: a randomised, double-blind, placebo-controlled trial. (opens in a new tab)
  4. Dietary vitamin D intake and 2-year changes in cognitive function in older adults with overweight or obesity and metabolic syndrome.
    2025Cohort study5,454 participants

    GeroScience

    Finding In this longitudinal observational study, higher dietary vitamin D intake was associated with greater two-year improvement in global, executive and language function after covariate adjustment.

    SupportiveView source for Dietary vitamin D intake and 2-year changes in cognitive function in older adults with overweight or obesity and metabolic syndrome. (opens in a new tab)
  5. Gestational vitamin D concentration and child cognitive development: a longitudinal cohort study in the Environmental influences on Child Health Outcomes Program.
    2025Cohort study912 participants

    The American journal of clinical nutrition

    Finding Each 10-ng/mL increase in gestational 25(OH)D was associated with greater overall and fluid cognition scores, but not crystallized cognition.

    SupportiveView source for Gestational vitamin D concentration and child cognitive development: a longitudinal cohort study in the Environmental influences on Child Health Outcomes Program. (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.