Supports Thyroid, Immune and Complete Metabolic Function Iodine with L-Tyrosine For Your Good Health Dietary Supplement Thyroid Care provides superior nutritional support for healthy thyroid and immune function. Optimal levels of iodine benefit the thyroid gland and enhance metabolism. L-Tyrosine plays an important role in the production of thyroid hormones. L-Tyrosine is an important amino acid which is absolutely necessary for the body to produce thyroid (as well as noradrenalin and dopamine) hormones. It is impossible to have a well functioning thyroid without sufficient quantities of tyrosine combined with iodine either in the diet or through supplementation.