Trace metals serve as cofactors for enzymes in the body, especially those necessary for sugar control and insulin activity. Cofactors increase the speed of reactions. Examples are chromium (Cr), zinc (Zn), selenium (Se), lithium (Li) and vanadium (Va). Deficiencies of any of these trace minerals appear to be important to immunity and metabolism. Cr increases insulin sensitivity, Se and Ze have antioxidant properties, and Va blocks phosphatases. These also provide promise for trace mineral therapies for diabetes.
People with Cr deficiency have impaired glucose tolerance, fasting hyperglycemia and abnormal lipids. Currently, a number of popular diet plans in the United States contain little Cr. Cr is poorly absorbed. High amounts of Cr are found in barley.
Hexavalent Cr is toxic. Cr picolinate is widely used since it is soluble in water at neutral pH. It is poorly absorbed into the blood stream. It seems to make the blood more sensitive to the insulin present. GTF (glucose tolerance factor) Cr from brewer’s yeast improves glucose transport in the presence of insulin. It contains Cr, nicotinic acid and 3 amino acids of glutathione. Cr may be best for treating insulin resistance.
Zn is important in the functioning of many enzymes, in insulin metabolism, and as an antioxidant. Zn is supplied through cereals, meat, seafood and dairy products, but it is not stored and must be consumed on a regular basis. Iron and copper compete with Zn for absorption, and Zn absorption is reduced in inflammatory bowel disease. Zn also helps stabilize insulin and in the storage of insulin in the pancreas. It is a very strong antioxidant. Some studies of diabetics report low levels of Zn and high levels of copper. Zn can correct oxidative stress, but slightly reduces the risk of type 2 diabetes in people who are only Zn deficient.
Dietary Se is a well-absorbed antioxidant. Complexes of Se and protein (selenoproteins) include glutathione peroxidase and thioredoxin reductase, which help direct Se to tissues. Low Se levels are seen in diabetics with oxidative stress. In young adults with the highest levels of Se, lower levels of triglycerides are found.
Va is known to have anti-diabetic properties, but it is uncertain whether Va is an essential element. It can cause side effects of weight loss, and gastrointestinal discomfort, while Va complexes have fewer side effects. Va has been called an “insulin mimetic”, but it may actually increase the effect of insulin. This may be why it doesn’t work well for insulin resistance. Interestingly, it may help in severe diabetes.
Li is used in neurological disorders, as well as mood and bipolar disorders. Magnesium levels have been found to be low in many people with type 2 diabetes, but there is some disagreement about the treatment of low magnesium in prediabetic states.
CONCLUSION: Overall, trace mineral supplementation in diabetes has not shown the beneficial results expected. Results are especially poor if the patient does not have a trace mineral deficiency. (Organic derivative forms of the minerals are better than nonorganic forms.)
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