Vanadium
Background
Vanadium, named after Vanadis, the Norse goddess of beauty, is a trace mineral associated with blood sugar regulation. In fact, prior to the discovery of insulin in 1922, vanadium was used for the control of blood sugar. Vanadium is believed to regulate fasting blood sugar levels and improve receptor sensitivity to insulin. Some evidence suggests that vanadium supports vital metabolic processes because of its ability to mimic the actions of insulin. In addition, in animal models, vanadium appears to decrease appetite and body weight in insulin-resistant animals.
Clinical Studies
Insulin Sensitivity
A number of small human studies have confirmed the effectiveness of vanadium in improving insulin sensitivity. In one small single-blind, placebo-controlled study of the effect of vanadyl sulfate on eight subjects with Type II diabetes, treated subjects received 50 mg vanadyl sulfate twice daily for 4 weeks. This was followed by a 4-week wash out placebo phase. Improvements in fasting glucose and hepatic insulin resistance followed the treatment period and were sustained throughout the placebo period.
In another trial, 100 mg vanadyl sulfate was given daily for 3 weeks to moderately obese Type II diabetic and non-diabetic subjects. A decrease in fasting
plasma glucose was observed, as well as a significant improvement in insulin sensitivity in the diabetic subjects. The authors concluded that at this dose vanadyl sulfate was capable of improving insulin sensitivity in Type II diabetic subjects. However, no change was noted in insulin sensitivity among obese, non-diabetics.
In another trial of vanadium, 11 Type II diabetic patients were treated with vanadium sulfate at a higher dose (150 mg/day) and for a longer period of time (6 weeks) than in previous studies. Before and after treatment, insulin secretion was tested during an oral glucose tolerance test. Treatment with vanadium significantly improved glycemic control. Fasting plasma glucose (FPG) decreased from an average of 194 to 155 mg/dL, hemoglobin A1c decreased from an average of 8.1 to 7.6, and average fructosamine decreased from 348 to 293. Vanadyl sulfate treatment also lowered the plasma total cholesterol from 223 to 202 on average. The authors concluded that vanadium sulfate for 6 weeks improves insulin sensitivity in Type II diabetics.
Dosage
Absorption of dietary vanadium and supplemental vanadium is poor. It is estimated that less than 5% of dietary vanadium is absorbed. Organic forms of vanadium, such as bis-glycinato oxovanadium (BGOV), are recognized as being more absorbable, in the range of approximately 50%. BGOV is an organically bound, bioavailable form of vanadium complexed with the amino acid glycine. Organic forms of supplemental vanadium have been shown to reduce the chances of gastrointestinal side effects seen with vanadium sulfate supplementation.
The daily dietary intake in humans has been estimated to vary from 10 mcg to 2 mg of elemental vanadium, depending on the environmental sources of this mineral in the air, water, and food of the particular region tested. In animals, vanadium has been shown essential (1 to 10 mcg vanadium per gram of diet). Organic forms of vanadium, as opposed to the inorganic sulfate salt of vanadium, are recognized as safer, more absorbable, and better able to deliver a therapeutic effect.
More research on vanadium is needed to establish an accurate dose/response for the treatment of insulin resistance. Based on current evidence, doses of vanadium from organic sources in the range of 1 to 10 mg/day short term (up to 1 month) and 0.5-2 mg/day long term seem reasonable. Vanadium therapy should only be undertaken with the guidance of a healthcare practitioner familiar with its use.
Safety and Side Effects
Based on available research, vanadyl sulfate appears to be a useful and safe intervention for Type II diabetic individuals with insulin resistance. In humans, administration of vanadium to athletes for up to 12 weeks at a dose of 225 mcg per pound of body weight (33.75 g/day for a 150-lb person) did not result in any toxicity. Further studies evaluating the long-term safety of vanadium compounds in humans is recommended.
