Iodine in biology
The U.S. Food and Nutrition Board and Institute of Medicine recommended daily allowance of iodine ranges from 150 micrograms per day for adult humans to 290 micrograms per day for lactating mothers. However, the thyroid gland needs no more than 70 micrograms per day to synthesize the requisite daily amounts of T4 and T3. The higher recommended daily allowance levels of iodine seem necessary for optimal function of a number of other body systems, including lactating breasts, gastric mucosa, salivary glands, oral mucosa, arterial walls, thymus, epidermis, choroid plexus and cerebrospinal fluid, among others.
Potassium
The U.S. Institute of Medicine (IOM) sets Estimated Average Requirements (EARs) and Recommended Dietary Allowances (RDAs), or Adequate Intakes (AIs) for when there is not sufficient information to set EARs and RDAs. Collectively the EARs, RDAs, AIs and ULs are referred to as Dietary Reference Intakes. The AIs for potassium are: 400 mg of potassium for 0-6-month-old males, 700 mg of potassium for 7-12-month-old males, 3,000 mg of potassium for 1-3-year-old males, 3,800 mg of potassium for 4-8-year-old males, 4,500 mg of potassium for 9-13-year-old males, and 4,700 mg of potassium for males that are 14 years old and older.
The AIs for potassium are: 400 mg of potassium for 0-6-month-old females, 700 mg of potassium for 7-12-month-old females, 3,000 mg of potassium for 1-3-year-old females, 3,800 mg of potassium for 4-8-year-old females, 4,500 mg of potassium for 9-13-year-old females, and 4,700 mg of potassium for females that are 14 years old and older.
The AIs for potassium are: 4,700 mg of potassium for 14-50-year-old pregnant females; furthermore, 5,100 mg of potassium for 14-50-year-old lactating females. As for safety, the IOM also sets Tolerable upper intake levels (ULs) for vitamins and minerals, but for potassium the evidence was insufficient, so no UL established.