Table 1.

Summary of the experimental details and main results obtained in the most relevant clinical trials regarding vanadium antidiabetic activity.

Oral Treatment	Experimental Design	Main Results	Reference
Vanadyl sulfate 100 mg/day (50 mg twice daily) 3 weeks active 2 weeks follow-up	Single-blind, placebo-controlled 6 T2D patients No diabetic subjects	Reduction in plasma glucose and HbA1c Reduction of FFA Gastrointestinal intolerance	[92]
Sodium metavanadate 125 mg/day (50 + 50 + 25 mg/daily) 2 weeks active 2 weeks follow-up	Non-randomized, non-placebo-controlled 5 T1D patients 5 T2D patients No diabetic subjects	No changes in insulin sensitivity in T1D patients No changes in plasma glucose and HbA1c in both diabetic types Decrease of total cholesterol in both diabetic types Mild gastrointestinal side effects in both diabetic types	[97]
Vanadyl sulfate 100 mg/day (50 mg twice daily) 4 weeks active 4 weeks follow-up	Single-blind, placebo-controlled 8 T2D patients No diabetic subjects	Reduction in plasma glucose No information about HbA1c Gastrointestinal side-effects	[93]
Vanadyl sulfate 100 mg/day (50 mg twice daily) 3 weeks active No follow-up	Single-blind, placebo-controlled 7 T2D patients 6 non-diabetic subjects	Reduction in plasma glucose and HbA1c Decrease of total cholesterol Reduction of FFA Minor gastrointestinal side-effects Stool discoloration	[94]
Vanadyl sulfate 75, 150, and 300 mg/day (25, 50, and 100 mg/3 times daily) 6 weeks active 2 weeks follow-up	Single-blind, placebo-controlled 16 T2D patients No diabetic subjects	Reduction in plasma glucose and HbA1c Some gastrointestinal intolerance	[95]
Vanadyl sulfate 150 mg/day (50 mg 3×/daily) 6 weeks active 6 weeks follow-up	Single-blind, non-placebo-controlled 11 T2D patients 5 non-diabetic subjects	Reduction in plasma glucose and HbA1c Minor gastrointestinal side-effects	[51]
BEOV Phase I—10–90 mg/day 2 weeks active No-follow up Phase II—20 mg/day 28 days 14 days follow-up	Single-blind, placebo-controlled 40 non-diabetic subjects Single-blind, placebo-controlled 7 T2D patients	No information about plasma glucose and HbA1c No side effects Reduction in plasma glucose and HbA1c Renal side effects	[101]