Systematic review and meta-analysis of randomised controlled trials testing the effects of vitamin C supplementation on blood lipids

Clin Nutr. 2016 Jun;35(3):626-37. doi: 10.1016/j.clnu.2015.05.021. Epub 2015 Jun 17.


Background & aims: Randomised controlled trials (RCTs) in humans revealed contradictory results regarding the effect of vitamin C supplementation on blood lipids. We aimed to conduct a systematic review and meta-analysis of RCTs investigating the effect of vitamin C supplementation on total cholesterol, low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C) and triglycerides and to determine whether the effects are modified by the participants' or intervention characteristics.

Methods: Four databases (PubMed, Embase, Scopus and Cochrane Library) were searched from inception until August 2014 for RCTs supplementing adult participants with vitamin C for ≥ 2 weeks and reporting changes in blood lipids.

Results: Overall, vitamin C supplementation did not change blood lipids concentration significantly. However, supplementation reduced total cholesterol in younger participants (≤52 years age) (-0.26 mmol/L, 95% CI: -0.45, -0.07) and LDL-C in healthy participants (-0.32 mmol/L, 95% CI: -0.57, -0.07). In diabetics, vitamin C supplementation reduced triglycerides significantly (-0.15 mmol/L, 95% CI: -0.30, -0.002) and increased HDL-C significantly (0.06 mmol/L, 95% CI: 0.02, 0.11). Meta-regression analyses showed the changes in total cholesterol (β: -0.24, CI: -0.36, -0.11) and in triglycerides (β: -0.17, CI: -0.30, -0.05) following vitamin C supplementation were greater in those with higher concentrations of these lipids at baseline. Greater increase in HDL-C was observed in participants with lower baseline plasma concentrations of vitamin C (β: -0.002, CI: -0.003, -0.0001).

Conclusions: Overall, vitamin C supplementation had no significant effect on lipid profile. However, subgroup and sensitivity analyses showed significant reductions in blood lipids following supplementation in sub-populations with dyslipidaemia or low vitamin C status at baseline. PROSPERO Database registration: CRD42014013487,

Keywords: Ascorbic acid; Cardiovascular risk; Cholesterol; Lipoproteins; Nutritional supplements; Triglycerides.

Publication types

  • Meta-Analysis
  • Review
  • Systematic Review

MeSH terms

  • Antioxidants / therapeutic use*
  • Ascorbic Acid / therapeutic use*
  • Ascorbic Acid Deficiency / diet therapy
  • Ascorbic Acid Deficiency / physiopathology
  • Ascorbic Acid Deficiency / prevention & control
  • Cardiovascular Agents / therapeutic use
  • Cardiovascular Diseases / epidemiology
  • Cardiovascular Diseases / etiology
  • Cardiovascular Diseases / prevention & control
  • Dyslipidemias / diet therapy*
  • Dyslipidemias / etiology
  • Dyslipidemias / physiopathology
  • Dyslipidemias / prevention & control
  • Humans
  • Hyperlipidemias / diet therapy
  • Hyperlipidemias / etiology
  • Hyperlipidemias / physiopathology
  • Hyperlipidemias / prevention & control
  • Hypolipidemic Agents / therapeutic use*
  • Oxidative Stress*
  • Randomized Controlled Trials as Topic
  • Reproducibility of Results
  • Risk


  • Antioxidants
  • Cardiovascular Agents
  • Hypolipidemic Agents
  • Ascorbic Acid