Abstract Title:

Effects of Vitamin C Supplementation on Glycemic Control and Cardiovascular Risk Factors in People With Type 2 Diabetes: A GRADE-Assessed Systematic Review and Meta-analysis of Randomized Controlled Trials.

Abstract Source:

Diabetes Care. 2021 Feb ;44(2):618-630. PMID: 33472962

Abstract Author(s):

Shaun A Mason, Michelle A Keske, Glenn D Wadley

Article Affiliation:

Shaun A Mason


BACKGROUND: Evidence suggests that vitamin C supplementation could be a potential therapy in type 2 diabetes. However, its effectiveness and evidence quality require further evaluation.

PURPOSE: To investigate the efficacy of oral vitamin C supplementation in improving glycemic control, cardiovascular risk factors, and oxidative stress in people with type 2 diabetes.

DATA SOURCES: Databases (PubMed, Embase, Scopus, Cochrane Library) and clinical trial registries were searched for randomized controlled trials up to 8 September 2020.

STUDY SELECTION: Trials in adults with type 2 diabetes were included. Trials were excluded if supplements were not exclusive to vitamin C and if<2 weeks in duration.

DATA EXTRACTION: Primary outcomes were HbA, glucose, cholesterol, triglycerides, and blood pressure (BP). Data were extracted for changes in outcomes between vitamin C and control groups. Evidence certainty was assessed using Grading of Recommendations, Assessment, Development, and Evaluation methods.

DATA SYNTHESIS: Twenty-eight studies (= 1,574 participants) were included in the review. Outcomes that changed to a statistically and clinically significant extent with vitamin C were systolic BP (mean difference -6.27 [95% CI -9.60, -2.96] mmHg;= 0.0002), with moderate evidence certainty, and HbA(-0.54% [-0.90, -0.17];= 0.004) and diastolic BP (-3.77 [-6.13, -1.42] mmHg;= 0.002) with very low evidence certainty.

LIMITATIONS: Studies were predominantly short term (<6 months) with a small number of participants (<100).

CONCLUSIONS: While evidence from short-term studies suggests that vitamin C supplementation may improve glycemic control and BP in people with type 2 diabetes, vitamin C supplementation cannot currently be recommended as a therapy until larger, long-term, and high-quality trials confirm these findings.

Study Type : Meta Analysis, Review

Print Options

Key Research Topics

Sayer Ji
Founder of GreenMedInfo.com

Subscribe to our informative Newsletter & get Nature's Evidence-Based Pharmacy

Our newsletter serves 500,000 with essential news, research & healthy tips, daily.

Download Now

500+ pages of Natural Medicine Alternatives and Information.

This website is for information purposes only. By providing the information contained herein we are not diagnosing, treating, curing, mitigating, or preventing any type of disease or medical condition. Before beginning any type of natural, integrative or conventional treatment regimen, it is advisable to seek the advice of a licensed healthcare professional.

© Copyright 2008-2022 GreenMedInfo.com, Journal Articles copyright of original owners, MeSH copyright NLM.