The parathyroids are embedded in the thyroid. Their hormone controls the levels of calcium and phosphorous in the blood. The level of calcium in the blood is important because it is involved in blood clotting, contraction of muscles, and the actions of the nerves.
Parathyroid Functions; Bone is constantly being broken down and renewed. The parathyroid’s job is to take calcium from this reservoir and add it to the body fluids when needed. The concentration of calcium in the body fluids can do its job properly only if kept within very narrow limits.
Cramps; Calcium & phosphorous are essential to the normal operation of the muscles and nerves. Parathyroid failure often causes an imbalance in calcium and phosphorous levels, which can result in muscle contractions, the serious form of which is called tetany.