Calcemia indicates the calcium levels in the blood. It is essential to the body and is particularly involved in the phenomena of blood clotting and muscular physiology. It also enters into the composition of bones and teeth. The normal amounts of calcemia generally vary between 2.2 and 2.5 mmol.l. Hypocalcemia, a low blood calcium concentration, is often associated with a deficiency of vitamin D and generates cramps or tetany. Otherwise, it is hypercalcemia which appears as fatigue, loss of appetite, paleness, vomiting, thirst, and increased urinary losses.