School of Exercise and Nutrition Sciences, Deakin University, Melbourne, Victoria, Australia
Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Victoria, Australia.
Diabetes Care. 2021 Feb;44(2):618-630. doi: 10.2337/dc20-1893.
Evidence suggests that vitamin C supplementation could be a potential therapy in type 2 diabetes. However, its effectiveness and evidence quality require further evaluation.
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.
Databases (PubMed, Embase, Scopus, Cochrane Library) and clinical trial registries were searched for randomized controlled trials up to 8 September 2020.
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.
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.
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.
Studies were predominantly short term (<6 months) with a small number of participants ( < 100).
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.
有证据表明，维生素 C 补充剂可能是 2 型糖尿病的一种潜在治疗方法。然而，其疗效和证据质量仍需进一步评估。
研究口服维生素 C 补充剂对改善 2 型糖尿病患者血糖控制、心血管危险因素和氧化应激的疗效。
检索了截至 2020 年 9 月 8 日的数据库（PubMed、Embase、Scopus、Cochrane 图书馆）和临床试验注册处，以寻找随机对照试验。
纳入了 2 型糖尿病成人患者的试验。如果补充剂不仅限于维生素 C 或持续时间<2 周，则排除试验。
主要结局指标为 HbA1c、血糖、胆固醇、甘油三酯和血压（BP）。提取了维生素 C 组和对照组之间结局变化的数据。使用推荐评估、制定与评价（Grading of Recommendations, Assessment, Development, and Evaluation）方法评估证据确定性。
共纳入 28 项研究（共 1574 名参与者）。维生素 C 可显著改变的结局包括收缩压（平均差值 -6.27[95%置信区间-9.60，-2.96]mmHg； = 0.0002），证据确定性为中度，以及 HbA1c（-0.54%[-0.90，-0.17]； = 0.004）和舒张压（-3.77[-6.13，-1.42]mmHg； = 0.002），证据确定性为极低。
研究主要为短期（<6 个月），参与者人数较少（<100 人）。
虽然短期研究的证据表明，维生素 C 补充剂可能改善 2 型糖尿病患者的血糖控制和血压，但在更大规模、长期和高质量的试验证实这些发现之前，不能推荐维生素 C 补充剂作为一种治疗方法。
