Day 6 of 12 Education: Hypothyroidism, also known as low thyroid function, affects about 10% of the population in the United States. Standard treatment is replacement of the T4 (thyroxine) hormone using levothyroxine (Synthroid). T4 must be converted to a thyroid hormone called T3 (triiodothyronine). This is accomplished by an enzyme called DIO2. Some individuals […]