Vitamin C for Diabetes

What if instead of taking Actos (pioglitazone) or Avandia (rosiglitazone) or Glucophage (metformin), the medication you really needed for blood sugar control in diabetes were vitamin C? A study coming from Iran suggests that for some diabetics, vitamin C might be as useful as many common medications.

Researchers at the Shahid Sadoughi University of Medical Sciences & Health Services followed 84 diabetics given either 500 mg or 1,000 mg of supplemental vitamin C every day for six weeks.

Taking 500 mg of vitamin C every day did not result in any measurable benefits. Diabetics taking 1,000 mg of vitamin C a day, however, had lower fasting blood glucose, lower triglycerides, lower LDL cholesterol, and lower HbA1C in just 42 days.

How much lower?

Average fasting blood glucose levels fell from 169.33 mg/dl to 144.80 mg/dl.
Average HbA1C fell from 8.82 per cent to 7.66 per cent. (This is better than most medications.)
Average LDL cholesterol fell from 130.95 mg/dl to 125.91 mg/dl.
And the drop in insulin levels was astonishing, from 16.91 microunits per ml to 8.77 microunits per ml.

When there is less insulin, there is less fat storage. Vitamin C should help diabetics keep from gaining weight.

These results suggest that many diabetics may benefit from vitamin C, but the results should be interpreted with some reservations. If you are already on one or several medications, the additional benefits of taking a 1,000 mg vitamin C tablet every day, at least in terms of your blood sugars, triglycerides, and HbA1c, may be limited. Also, vitamin in your blood interacts with the enzymes in blood glucose test strips so that the glucometer reading is low, while the actual blood sugar is higher.

It's also possible that using vitamin C for several months can, like using R-lipoic or alpha-lipoic acid, give you a reduction in HbA1C that doesn't really result from improved blood sugars. Doctors test HbA1C to get a rough estimate of how high or low blood sugars have run over several months. Strong antioxidants keep glucose from "sticking" to hemoglobin, so less HbA1C is formed at the same blood sugar level.

The effects of vitamin C on blood sugar measurements of various kinds may not be major, but they do tend to exaggerate the vitamin's benefits. Where vitamin C might really help you is to keep you from gaining weight.

Just get your C from an extended-release formula, and make sure you don't take more than 1,000 mg a day. And if you're really concerned about the question "How much vitamin C should I get daily," be assured you may get some benefits from just 250 mg a day (even though the study did not show this, some other studies suggest it). You don't need high-dose vitamin C crystals or capsules for this indication.

What fruit has the highest content of vitamin C? Acerola, but if you don't live in a tropical location where you can get acerola fresh, just about the only way you can get enough vitamin C to affect blood sugars is to take a supplement.

Vitamin C is also important for diabetics' cardiovascular health.

That's because the amount of vitamin C a diabetic gets may also measure risk of stroke. Among the 20,649 participants in the Norfolk Prospective Population Study in the UK, those whose bloodstream concentrations of vitamin C ranked in the top 25 per cent were 42 per cent less likely to have a stroke than those in the bottom 25 per cent.

This finding does not prove that diabetics can prevent strokes by taking vitamin C, or even confirm with certainty that diabetics can reduce their risk of stroke by taking vitamin C. It is possible that there's some other element of a healthy lifestyle that goes along with getting enough vitamin C that's really protective. This study does show, however, that getting adequate vitamin C certainly does not hurt diabetics' cardiovascular health.

Citations:

Afkhami-Ardekani M, Shojaoddiny-Ardekani A. Effect of vitamin C on blood glucose, serum lipids & serum insulin in type 2 diabetes patients. Indian J Med Res. 2007 Nov;126(5):471-4.


Myint PK, Luben RN, Welch AA, Bingham SA, Wareham NJ, Khaw KT. Plasma vitamin C concentrations predict risk of incident stroke over 10 y in 20 649 participants of the European Prospective Investigation into Cancer Norfolk prospective population study. Am J Clin Nutr. 2008 Jan;87(1):64-9.