Vanadium is an element present in almost all human tissues and is found at highest concentrations in the kidneys, liver, testes, teeth, and bone. Although the ideal daily intake of vanadium has not yet been established, estimates of optimal intake range from 10-300 mcg per day. Animal studies have demonstrated that vanadium exerts a positive effect on glucose metabolism, mimicking the effects of insulin and stimulating insulin release from the pancreas. It also appears to play a role in thyroid function, keeping cholesterol levels in check, and preventing cavities. Deficiencies in vanadium result in decreased growth, liver changes, and decreased thyroid function in animals. Food sources of vanadium include buckwheat, black pepper, parsley, soy, safflower oil, eggs, sunflower seeds, oats, and olive oil.