Huge Tehran Research Shows Vitamin C Found to Lower Blood Sugar in Type 2 Diabetes

Susanna Sisson's picture
Vitamin C and lowering blood Sugar

A new study in the Journal of Pharmacy and Pharmaceutical Science has found taking vitamin C helps lower fasting blood sugar in type 2 diabetes mellitus (T2DM) by an average of 21mg/dl, although it did not have a definitive effect on glycated hemoglobin (HbA1c). The research included 38 articles; 26 observational studies and 12 random controlled trials (RCTs).


A team from the University of Tehran performed meta-analysis on all studies relating to ascorbic acid (AA) or vitamin C prior to January 2013. They drew the data from several sources including Google Scholar, PubMed, Scopus, IranMedex and Magiran data bases. The researchers included observational data and randomized controlled trials and excluded studies on Type 1 diabetes mellitus, pediatric studies, animal studies, or studies involving gestational diabetes and pregnant women.

Diabetes affects nearly 400 million people worldwide and is a serious problem that is associated with cardiovascular issues and metabolic syndrome and is the leading cause of both blindness and amputations. By 2035 the number of people with diabetes is expected to rise to 592 million.

Diabetes is related to inflammation secondary to oxidative stress formation which affects the islet cells of the pancreas ability to secrete insulin. It is often associated with weight gain. T2DM is seen more often in people who make poor dietary choices and do not have availability of high quality foods such as fruits, vegetables, grains, and good protein sources, therefore there are socioeconomic factors to consider.


Vitamin C is an essential, water-soluble micronutrient primarily found in fruits and vegetables although it is readily available as an over the counter supplement and approximately 12% of the population routinely supplements with vitamin C. The nutrient can have both pro-oxidant and anti-oxidant effects and the anti-oxidant effect is seen at higher levels. Because the vitamin is water soluble excess amounts are simply excreted through either urine or stool so it is not likely anyone could take an amount which could be toxic.

The beneficial effect of AA consumption in diabetes is controversial. Some studies support the idea that due to impairment of insulin secretion vitamin C is necessary to optimize islet cells ability to secret insulin. Others did not show any correlation which may have been due to a flaw in the study design.

However vitamin C does have other beneficial effects such as boosting the ability of the immune system to fight infections. Effects on the cardiovascular system include lowering cholesterol and improving circulation which may lower the incidence of heart attack and stroke. It may also help improve symptoms of asthma and COPD and one study showed it can be useful in the treatment of tuberculosis (TB). Vitamin C improves the appearance of skin and improves wound healing. Adequate amounts of vitamin C may prevent issues with aging including arthritis, cataracts, dementia and Alzheimer’s. This essential nutrient has also been shown to reduce the incidence of cancer.

So, whether lowering your blood sugar is the goal or merely protecting against the common cold or flu, or in anti-aging, getting adequate amounts of vitamin C is the smart thing to do.

2. Thehealthsite