Carotenoids, vitamin A, and their association with the metabolic syndrome: a systematic review and meta-analysis

source extracted confidence: high 2026-04-09
#carotenoids #case-control-studies #cohort-studies #cross-sectional-studies #humans

Carotenoids, vitamin A, and their association with the metabolic syndrome: a systematic review and meta-analysis

Beydoun et al., 2019 | Nutr Rev | Meta Analysis

Citation

Beydoun May A, Chen Xiaoli, ... Canas Jose A. Carotenoids, vitamin A, and their association with the metabolic syndrome: a systematic review and meta-analysis. Nutr Rev. 2019-Jan-01;77(1):32-45. doi:10.1093/nutrit/nuy044

Abstract

CONTEXT: Modifiable factors that reduce the burden of the metabolic syndrome (MetS), particularly plant-derived biomarkers, have been a recent focus of rising interest. OBJECTIVE: This systematic review and meta-analysis, which follows PRISMA guidelines, evaluates evidence from a period of 20 years that links vitamin A and carotenoids with the occurrence of MetS and following the PRISMA guidelines. DATA SOURCES: PubMed and Cochrane databases (January 1997 through March 2017) were systematically assessed for studies, including case-control, cross-sectional, and cohort studies, that evaluated the associations of MetS with carotenoids and retinyl esters and retinol (vitamin A). DATA EXTRACTION: Key measures of associations were harmonized into odds ratios (ORs) and 95% confidence intervals (95%CI) of MetS per 1 standard deviation (SD) of exposure using forest plots and random effects models that pooled data points from 11 cross-sectional studies. Begg's funnel and harvest plots were constructed. RESULTS: An inverse association between total carotenoids and MetS was found [ORpooled, 0.66; 95%CI, 0.56-0.78; 1 SD ∼ 0.82 µmol/L; n = 5 studies]. This association was the strongest for β-carotene, followed by α-carotene and β-crypotoxanthin. No association was detected between retinol and MetS (ORpooled, 1.00; 95%CI, 0.88-1.13; 1 SD ∼ 2.14 µmol/L; n = 6 studies). Publication bias was absent, and harvest plots indicated consistency upon replication for β-carotene and total carotenoid exposures. CONCLUSIONS: This review and meta-analysis suggests that, unlike retinol, total and individual carotenoids were inversely related to MetS.

Key Findings

An inverse association between total carotenoids and MetS was found [ORpooled, 0.66; 95%CI, 0.56-0.78; 1 SD ∼ 0.82 µmol/L; n = 5 studies]. This association was the strongest for β-carotene, followed by α-carotene and β-crypotoxanthin. No association was detected between retinol and MetS (ORpooled, 1.00; 95%CI, 0.88-1.13; 1 SD ∼ 2.14 µmol/L; n = 6 studies). Publication bias was absent, and harvest plots indicated consistency upon replication for β-carotene and total carotenoid exposures.

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population See abstract
Sample Size 5
Age Range See abstract
Condition See abstract

MeSH Terms

  • Carotenoids
  • Case-Control Studies
  • Cohort Studies
  • Cross-Sectional Studies
  • Humans
  • Metabolic Syndrome

Evidence Classification

  • Level: Meta Analysis
  • Publication Types: Journal Article, Meta-Analysis, Research Support, N.I.H., Intramural, Systematic Review
  • Vertical: vitamin-a

Provenance

Source extracted via PubMed E-utilities API on 2026-04-09