Vanadium is a trace mineral available naturally that mimics insulin, thus is found to lower blood sugar. However, research has shows that although this incident occurs at first, prolonged use may have toxic effects on the body. check out this article on
Vanadium in diabetes: benefit or harm?, by John Walsh, covers vanadium and other trace minerals in diabetes.
On Diab-X, there are quite a number of conflicting data on its authenticity or not. If you would like to take a risk, then you may try taking it. If not, then just try medications that are prescribed to you by your doctor. Diab-X is considered a supplement, and not a medication.
Hope this helps.