Is Vanadyl Sulfate Safe?

Q: I have diabetes, and I started taking the amount of vanadyl sulfate you suggest, 100 mg a day. I read that this can cause a green tongue and other problems. Since this is part of your recommendations, I would like to know what you have discovered about this. I am especially interested in the toxicity issue. Thanks for your help.

A: I’m happy to answer this question because it pops up from time to time.

Vanadyl sulfate is a stable, inorganic form of vanadium, a metallic element used primarily as an additive in steel production. Acute exposure to the dust or fumes of vanadium or various vanadium compounds can be toxic to the nervous and respiratory systems, liver, and other organs. And “green tongue” (as the name suggests, a greenish discoloration of the tongue) is indeed a classic symptom of toxicity in miners, industrial workers, or others exposed to high levels of vanadium.

But the accusation—often repeated on the Internet and elsewhere—that nutritional supplements containing minute amounts of vanadyl sulfate are toxic, is completely unfounded.

On the contrary, studies demonstrate that vanadyl sulfate is safe when taken in doses of 75, 150, and even 300 mg per day for prolonged periods. Some study subjects taking the higher dosage reported gastrointestinal disturbances, including harmless discoloration of the stool, but in most cases this resolved over the study course.

What I find most remarkable about these studies is that benefits usually endured after the supplement was discontinued, suggesting that vanadyl sulfate has an ameliorating effect on the underlying diabetic condition. Now you understand why this supplement has been the cornerstone of my treatment protocol for diabetes for more than 20 years.

So why do rumors of toxicity persist, despite the fact that vanadyl sulfate is, hands down, much safer than the scores of FDA-approved diabetes medications? A cynic might say it’s because widespread use would cut into the enormous profits reaped by the pharmaceutical companies—not to mention that a number of vanadium compounds are in the drug pipeline.

Whatever the reason, I stand by my recommendations for patients with diabetes: 100 mg of vanadyl sulfate daily along with other targeted nutrients, a low-glycemic diet, exercise after every meal, and weight loss.

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