Calcium plays an important role in our bodies and is necessary for life. In addition to building bones and keeping them healthy, this mineral enables our muscles to contract, our blood to clot, and our heart to beat; together with magnesium, calcium causes the heart muscle to contract properly. Calcium also plays an important role in the transmission of nerve impulses and is involved in cell growth and hormone metabolism. In addition, calcium transports sodium, potassium and magnesium through our bodies. The correct ratio of calcium (and also of magnesium) in the blood depends on parathormone. This hormone can only work properly if there is enough magnesium in the blood. So calcium and magnesium are interdependent. That is why it is important to eat a varied diet in order to get all the nutrients that work together in the body. Moreover, calcium maintains the acid-base balance by making the body less acidic and more alkaline. Its action in the digestive system is very important. In this way, calcium protects our bodies against colon cancer.

The maximum intake for calcium is about 2.5 g per day. An excess of calcium can lead to constipation, kidney stones, reduced absorption of other minerals and even cardiovascular disease. You can only get an excess of calcium through supplements, because through nutrition it is almost impossible; it is therefore better to get calcium from food than from supplements.

Another problem may be a vitamin D deficiency. If your body does not produce enough vitamin D, not all calcium that is ingested can be absorbed in the intestines. But we do not call this a surplus of calcium, but an impeded absorption of calcium. The calcium that has not been absorbed must be excreted, which is harmful to the kidneys. People who already have malfunctioning kidneys and are on medication should be careful with calcium and ask their doctor for advice.

As I just mentioned, sufficient vitamin D is required to absorb calcium in the bones. Most of vitamin D is produced in our bodies under the influence of the sun. We should get about a third through food. About 25% of the calcium we take in through nutrition is actually absorbed by the body. However, on average 50% calcium is taken from green leafy vegetables. An exception is spinach, where about 5% of the calcium present is absorbed. This is due to the oxalic acid in spinach; in the digestive system, calcium binds to the acid to neutralize and excrete it. But apart from that, spinach is healthy because of many other bioactive substances. Exercise is also very important for the proper absorption of calcium; if your muscles move little, the absorption of calcium is negatively affected.

A high intake of sodium (table salt) can interfere with the absorption of calcium and increase the excretion of calcium from the body. A negative link has also been found between obesity, caffeine, soft drinks, smoking and (excessive) alcohol consumption and the absorption of calcium.

We lose calcium every day. If we eat a lot of unhealthy products, we lose more calcium than normal. Our bodies cannot produce their own calcium. So it is very important to get enough calcium through our diets. When we lose too much calcium and don’t get enough from the foods we eat, it is taken from our bones and teeth where about 99% of the calcium in our bodies is stored. If it happens too often, bones and teeth get weak and can more easily break. For this reason, our diets should contain a variety of different calcium-rich foods.So put more calcium-rich foods on your menu, and enjoy!