Potassium iodide consists of 76.45% iodine and 23.55% potassium by mass. Potassium plays an important role in human metabolism and is essential for proper muscle function, certain neurological mechanisms, and as an electrolyte. As an essential nutrient, humans need a continual dietary supply of iodine to maintain good health (see table below for the Recommended Dietary Allowance based on age). In the event of radiation exposure, potassium iodide can dramatically reduce thyroid uptake of radiation. It may also inhibit the accumulation of lead following exposure.