Efficacy of Vitamins on Cognitive Function of Non-Demented People: A Systematic Review and Meta-Analysis

Nutrients. 2020 Apr 22;12(4):1168. doi: 10.3390/nu12041168.


Previous evidence has suggested that vitamins might be beneficial for cognition. This systematic review aimed to investigate the efficacy of B vitamins, antioxidant vitamins, and vitamin D on the cognitive function of non-demented middle-aged or older people. Randomized or quasi-randomized controlled trials of individuals aged 40 years or older were included. PubMed/MEDLINE, EMBASE, CINAHL, PsycINFO, Cochrane Library databases, and other grey literature sources were searched up to November 2019. Their methodological quality was evaluated using the Cochrane Risk of Bias tool. Twenty-three studies on B vitamins (n = 22-1053; comprising folate, B6, and B12), nine on antioxidant vitamins (n = 185-20,469), and six on vitamin D (n = 55-4122) were included. Taking B vitamins for over 3 months was beneficial for global cognition (standardized mean difference (SMD) -0.18, 95% CI -0.30 to -0.06) and episodic memory (SMD -0.09, 95% CI -0.15 to -0.04). However, antioxidant vitamins (SMD -0.02, 95% CI -0.08 to 0.03) and vitamin D (SMD -0.06, 95% CI -0.36 to 0.23) were not. Antioxidant vitamins were beneficial for global cognition in sensitivity analyses using final measurement data as mean difference estimates (SMD, -0.04, 95% CI -0.08 to -0.01). Taking B vitamins and possibly antioxidant vitamins may be beneficial for the cognitive function of non-demented people.

Keywords: B vitamins; antioxidants; cognitive; vitamin D.

Publication types

  • Meta-Analysis
  • Systematic Review

MeSH terms

  • Adult
  • Age Factors
  • Aged
  • Aged, 80 and over
  • Antioxidants / administration & dosage
  • Antioxidants / pharmacology*
  • Cognition / drug effects*
  • Female
  • Healthy Aging / psychology*
  • Humans
  • Male
  • Memory, Episodic
  • Middle Aged
  • Randomized Controlled Trials as Topic
  • Vitamin B Complex / administration & dosage
  • Vitamin B Complex / pharmacology*
  • Vitamin D / administration & dosage
  • Vitamin D / pharmacology*


  • Antioxidants
  • Vitamin B Complex
  • Vitamin D