WebMD says that vanadium is a mineral. Vanadium supplements are pills that provide vanadium in a concentrated form. Some people take vanadium supplements to treat diabetes, heart disease, high cholesterol and water retention. WebMD says there is some evidence to support the use of vanadium to treat diabetes.
WebMD reports that one very small study found that taking high doses of vanadium lowered blood sugar.
If taken in low doses vanadium is likely to be safe. However, high doses of vanadium can cause diarrhea, nausea, abdominal discomfort, a greenish tongue, fatigue, problems with the nervous system and possibly kidney damage.