The calcium value is routinely determined in many laboratory tests today. According to the German Society for Endocrinology (DGE), about one percent of the general population and three percent of women after menopause show slightly increased values. Long-term, slightly elevated calcium levels could be harmful to health and lead to kidney stones, fatigue, gastrointestinal problems, osteoporosis and vascular diseases. It can also be a symptom of various diseases. Therefore, a so-called hypercalcaemia should always be clarified, advises the DGE.
“Calcium has various functions in the body,” says Stephan Scharla, spokesman for the Bone and Mineral Metabolism Section of the DGE: “The largest amount is stored in the bones and ensures bone stability. In addition, the mineral is essential for signal transmission in cells and blood clotting.” Calcium also plays an important role in muscle function and the transmission of impulses in nerve cells and thus also influences heart muscles and heart function.
The most common cause of elevated blood calcium levels is primary hyperparathyroidism (pHPT). “About half of those affected suffer from it,” says Scharla. This is where the parathyroid glands are overactive: one or more of the four small organs located “next to” the thyroid glands release parathyroid hormone in an uncontrolled manner.
Normally, this hormone, in combination with vitamin D and calcitonin, ensures a normal calcium level in the blood. For example, if there is too little calcium in the blood, more parathyroid hormone is released and as a result the calcium level in the blood normalizes. In pHPT, this feedback is suspended and too much parathyroid hormone is released.