No other mineral is found in the human body in such large quantities as calcium (calcium). An adult carries 1,000 to 1,500 grams, with 99 percent of the mineral in the bones and teeth. However, calcium not only strengthens the skeleton, but also plays an important role in the work of muscles, blood clotting, heart rhythm and important metabolic processes. What effect a deficiency or an overdose can have and which foods are rich in calcium, you will learn below.
Calcium: effect in the body
The main function of calcium, which is also called calcium, is to form hard tissue in the body. Thus, it is essential for the formation, growth and reformation of bones and teeth. For this reason, children and adolescents in particular have a high demand for calcium. In addition to its importance in the mineralization of bones and teeth, calcium is also needed in the blood plasma, where it has various tasks – among other things, it is needed for blood clotting and contributes to the stabilization of cell walls. Depending on requirements, calcium is released for this purpose from the bones, which serve as a depot. Excess calcium is simply excreted by the body in the stool. Since calcium plays a central role in the formation of bones, a deficiency of the mineral can cause them to become porous and brittle – the technical term for this is osteoporosis. Even though the disease usually only occurs at an older age, it is important to know that prevention should be taken at a young age. This is because bone formation is complete by the age of 30 at the latest, by which time hardly any new calcium is stored in the bones.
Vitamin D: important for the absorption of calcium.
In order to better absorb calcium, the body also needs vitamin D. If the vitamin is not present in sufficient quantities, calcium cannot pass from the gastrointestinal tract into the blood and from there into the bones. The body then begins to break down bone mass in order to maintain the calcium concentration in the blood. Vitamin D is mainly produced by our skin under the influence of UV radiation. So a walk in the sun is important for the production of vitamin D and thus for the adequate supply of calcium to the bones. In addition, small amounts of vitamin D can also be taken in through food. The vitamin is found in whole grain products, legumes and dried fruits, bananas and apricots.
Daily requirement of calcium
The recommended daily allowance of calcium for adults is 1,000 milligrams. Children ages 10 to 19 have a higher requirement for the mineral, which is 1,100 milligrams, or 1,200 milligrams daily for ages 13 and older. Younger children have a lower requirement, depending on their age, according to the recommendations of the German Nutrition Society (DGE). For infants, the requirement is 220 to 330 milligrams, and for children between one and under ten years of age, it is 600 to 900 milligrams per day.
Foods with calcium
Calcium enters the body through food and is found primarily in milk and dairy products. Therefore, the foods richest in calcium include raw milk, buttermilk, cheese and cottage cheese. But hard drinking water (mineral water with more than 150 milligrams of calcium per liter is advisable), coconut flakes, sesame seeds, eggs, hazelnuts and various vegetables such as spinach leaves, kale, fennel or broccoli also contain not insignificant amounts of calcium. In addition, some foods such as juices or vegan or plant-based milk alternatives such as almond milk are often fortified with calcium. The ratio of calcium and magnesium in the body is also important. It should always be 2:1. 1,000 milligrams of calcium are contained in:
- 100 grams of Parmesan
- 200 grams chervil
- 300 grams soybeans
- 300 grams mozzarella
- 700 grams yogurt
- 800 grams of milk
- 1000 grams of granular cream cheese
Calcium deficiency and its consequences
The body stores calcium in the bones, from where it is released into the blood when needed. If the need for calcium in the long term is higher than is absorbed through food, sooner or later the bones become brittle. In the long term, a relative or absolute calcium deficiency can lead to osteoporosis (“bone atrophy”), rickets (“bone softening” in children), cataracts (a clouding of the lens of the eye) and muscle weakness.Short-term high calcium deficiency manifests itself in the form of painful muscle cramps and sensory disturbances, such as a tingling sensation around the mouth area.
Calcium overdose
Calcium overdose (hypercalcemia) is usually resolved by the body itself simply releasing the excess of the mineral through the stool. However, with simultaneous intake of vitamin D, when taking calcium tablets, or in the case of certain diseases, calcium excess can occur. In such an overdose, symptoms such as nausea, vomiting, constipation, fatigue and muscle weakness then occur. The increased excretion via the kidneys can result in dangerous fluid deficiency. In the long term, gallstones, urinary stones, stomach ulcers, kidney calcification and kidney stones can develop. To avoid overdosing, the proportion of calcium taken daily from dietary supplements should not exceed 500 milligrams, according to the recommendations of the German Federal Institute for Risk Assessment (BfR), since people usually take in a sufficient amount through their food.
Laboratory values: What does the calcium value in the blood say?
In the case of diseases of the thyroid gland or kidneys, the calcium value in the blood is often determined – in certain cases, the value in the urine is also determined. The normal value for the concentration of calcium in blood serum is 2.02 to 2.6 mmol/l in adults, and a blood value of 2.05 to 2.7 mmol/l is considered normal in children. Low calcium levels can indicate kidney disease, hormone disorders or a vitamin deficiency, among other things, or occur as a side effect of certain medications. Elevated levels usually indicate that calcium has been released from the skeleton – the cause (in addition to vitamin D overdose) is often other diseases, such as hyperthyroidism or diseases of the lungs.
