Thyroid hormones which causes the thyroid to enlarge (the resulting medical condition is called "endemic colloid goitre"; see goitre). This has the effect of increasing the thyroid's ability to trap more iodide, compensating for the iodine deficiency and allowing it to produce adequate amounts of thyroid hormone. Most of the thyroid hormone circulating in the blood is bound to "transport protein"s. Only a very small fraction of the circulating hormone is free (unbound) and biologically active, hence measuring concentrations of free thyroid hormones is of great diagnostic value. When thyroid hormone is bound, it is not active, so the amount of free
Trace metal vegetables are sources. Taken in excessive amounts, trace elements can cause problems. For example fluorine is required for the formation of bones and enamel on teeth. However, when taken in an excessive amount can cause a disease called "Fluorosis', in which bone deformations and yellowing of teeth are seen. Fluorine can occur naturally in some areas in ground water. Trace metals include iron that can help to prevent anemia, and zinc that is a cofactor in over 100 enzyme reactions. Trace metal Trace metals are the metals subset of trace elements; that is, metals normally present in small but measurable