Medastim, 100 C, Biotics ResearchMeda Stim supplies vitamins, minerals, amino acids, and botanical constituents to support the normal conversion of thyroid hormones, T 4 to T 3. In the bloodstream, T3 and T4 are carried by thyroine binding globulin, thyroxine binding preablumin and serum albumin. T4 is converted to T3 by the liver, lungs, kidneys and heart by a selenium dependent enzyme called Iodothyronine 5'monodeiodinase. T3 is then taken up by appropriate target cells, where it