Calcium is one of the most important and abundant minerals in your body, stored to 99% in bones and teeth. Besides providing structure, it plays an essential role in muscle function and is also important for transmission of nerve signals, enzyme regulation and the circulatory system. Calcium is important for maintaining normal blood pressure, a balanced coagulation and facilitating a regular heart rhythm.
Normal calcium levels suggest good bone health and healthy parathyroid glands.
Measuring calcium levels is useful when identifying and diagnosing any condition which commonly affects calcium levels. It is also relevant when evaluating the severity of conditions which indirectly may affect your calcium levels.
This is (almost always) equivalent with conditions affecting your bones, your teeth, your heart, or your kidneys. To name a few, your vitamin D status, kidney health and the function of your parathyroid glands can all be assessed with the help of measuring calcium levels.
Low calcium levels, also known as hypocalcemia, may be caused by:
increased excretion of calcium through the kidneys
decreased release of calcium from bones
a malabsorption from the intestines and diet.
The most common cause behind reduced calcium levels is however low albumin levels in blood, potentially resulting in liver disease or malnutrition. Other underlying causes include vitamin D deficiency, certain medications including anticonvulsants and bisphosphonates, and conditions in the parathyroid gland such as hypoparathyroidism.
High calcium levels, also known as hypercalcemia, indicate underlying medical conditions which can disrupt the calcium balance by increasing absorption of calcium from the diet, preventing excretion by the kidneys or increasing the release of calcium from bone.
The two most common causes behind elevated levels of calcium are overactive parathyroid glands (hyperparathyroidism) and cancer. Both of these conditions cause increased release of calcium from bones.
Increased absorption from diet however, may be caused by for example vitamin D toxicity and high levels of estrogen. Preventing excretion from kidneys are most often caused by certain medications including thiazide diuretics and lithium.