Analyzing elements can provide insight into why you may not synthesize or convert thyroid hormones and can help determine the cause of thyroid related symptoms. The thyroid gland regulates cellular energy metabolism, as well as controls heart rate and protein synthesis for proper growth and development. This profile includes Dried Urine tests for: Iodine, Bromine, Lithium, Selenium, Arsenic, Cadmium, Mercury and Creatinine.