John Myers
Many people do not get enough calcium in their diet. But are dietary supplements necessary?
The essentials in brief:
- Among other things, calcium plays a role in muscle function, bone and tooth formation and as a cellular messenger.
- It is found in many foods, especially in milk and milk products, additional calcium products are usually not necessary.
- More than 500 mg of calcium per day from dietary supplements (not from other foods) can lead to kidney stones and vascular calcification.
What is behind the advertisement for calcium?
Manufacturers of calcium products advertise their products with legally permitted statements such as “calcium has a role in cell division and specialization”, “calcium contributes to normal muscle function”, “calcium contributes to normal blood clotting” or “calcium is used for maintenance of normal bones”.
Indeed, calcium is an essential mineral and many individuals fall short of recommended intakes. The National Consumption Study II showed that a large proportion of young women and people aged 65 and over fall well short of the recommendations. Too little intake does not necessarily mean that there is a deficiency, but it can be an indication of an undersupply.
Certain dietary trends result in less calcium being absorbed. Vegan eaters, for example, often avoid any milk and milk products for ethical reasons. Even people with a lactose intolerance or milk allergy can consume little or no milk products. But are dietary supplements necessary? We are of the opinion: With a clever combination of foods, it is quite possible to cover the calcium requirement through food.
What should I watch out for when using additional calcium?
Overdoses from a very high calcium intake can lead to kidney stones in the long term. Arteriosclerosis ( hardening of the arteries ) is not the result of too much calcium (calcium). However, a connection between calcium products and heart attacks or strokes has often been discussed in the recent past. It is known that people who have genetically increased blood calcium concentrations are more likely to develop coronary heart disease or heart attacks. However, a connection to the intake of calcium products has not yet been clearly proven. Different studies bring conflicting results.
The European Food Safety Authority (EFSA) considers a maximum daily total calcium intake of 2500 mg (from all sources) to be safe. This amount should not be exceeded. The Federal Institute for Risk Assessment (BfR) therefore advises a maximum intake of 500 mg of calcium from food supplements (NEM). Supplements with added calcium of more than 250 mg per daily intake should bear the instruction to refrain from consuming other calcium-containing supplements.
The German Society for Endocrinology is currently warning:
Calcium intake by means of tablets, if dosed at more than 500 mg/day, can result in kidney stones and vascular calcification. In addition, since many patients take multiple dietary supplements, accidental overdose is possible. However, there are no harmful upper limits for calcium-rich foods.
In principle, it is always advisable to seek medical advice before resorting to dietary supplements .
These mineral compounds are approved for calcium in food supplements in Germany and other EU countries in accordance with EU Directive 2002/46/EC, Annex II (version dated March 20, 2021):
- Calcium acetate
- Calcium-L-ascorbat
- Calciumbisglycinat
- calcium carbonate
- Calciumchlorid
- Calciumcitratmalat
- Calcium salts of citric acid
- Calciumgluconat
- Calciumglycerophosphat
- Calciumlactat
- Calciumpyruvat
- Calcium salts of orthophosphoric acid
- Calciumsuccinat
- Calciumhydroxid
- Calcium-L-lysinat
- Calciummalat
- calcium oxide
- Calcium-L-pidolat
- Calcium-L-threonat
- Calciumsulfat
- Calcium-Phosphoryl-Oligosaccharide
What does the body need calcium for?
Like magnesium, calcium is necessary for the formation of bones and teeth. About 25 to 30 g of calcium is stored in an infant’s body. In the bones and teeth of adults you can even find up to 1.3 kg. In the cells themselves, calcium serves as a messenger substance and transmits signals. For example, the release of calcium leads to muscle movement. It is also possible to transmit sensory stimuli such as hearing and seeing. Without calcium we would also be in constant danger of bleeding to death, because the mineral is of fundamental importance in blood clotting.
A calcium blood level that is too low, caused for example by taking dehydrating drugs (diuretics) or certain antibiotics, leads to cramps, among other things.
Poor nutrition is rarely the cause of low calcium levels in the blood, as the body has various regulatory mechanisms. If necessary, the parathyroid hormone and an active form of vitamin D ensure that calcium is taken from the bones and the calcium level in the blood is maintained.
A calcium deficiency can therefore lead to long-term damage to the skeleton. Up to around the age of 30, the bones are still mineralized, which means that they harden and become stable. From around the age of 35, bone loss predominates. Hardly any calcium is stored and the bone mass decreases continuously. If too little calcium is ingested with food, the bone loss progresses all the faster. As a result, the risk of suffering from broken bones increases enormously in old age. Adequate calcium intake is therefore the best way to prevent so-called “osteoporosis”.
A calcium deficiency in childhood has serious consequences. An unbalanced diet and additional vitamin D deficiency, for example due to spending too little time outdoors, can lead to insufficient ossification of the bones, a so-called “rickets”. Sick children suffer lifelong consequences such as short stature or bent, brittle bones. However, rickets is rare nowadays in Western countries with a good food supply.
Risk groups for calcium deficiency include older people, especially postmenopausal women. Furthermore, all persons who abstain from milk and milk products for ethical or health reasons can be affected. As with all other nutrients, diseases of the digestive tract such as chronic inflammatory bowel diseases or short bowel syndrome pose a risk.
The German Society for Nutrition (DGE) recommends that adults over the age of 19 consume around 1000 mg daily. This includes calcium losses that occur during digestion. The requirement of pregnant and breastfeeding women is not increased in the case of calcium, but that of young people between 13 and 18 years of age: with 1200 mg per day, they need the most calcium.
Can I cover my daily requirement through food?
Calcium can be found in many foods. These include plant-based foods like kale, broccoli, arugula, fennel, and nuts (hazelnuts, Brazil nuts). The classic source of calcium from animals is milk or foods made from milk, such as cheese (especially hard cheeses). Calcium can also be absorbed through calcium-containing mineral water (> 150 mg per liter).
On average, the body can only absorb between 30 and 50% of the calcium contained in food. The reason: Plant-based foods in particular contain other substances that impede calcium absorption. This includes oxalic acid, which is found in rhubarb and spinach, for example, or phytic acid in the bran components of (whole grain) cereals. Both substances combine with calcium to form larger building blocks that can no longer be absorbed in the intestine and are excreted instead.
Calcium from dairy products is therefore better usable. Not only that there is neither oxalic nor phytic acid. Here even lactic acid and lactose promote the absorption of calcium. The DGE therefore recommends incorporating two to three servings of milk or milk products into the diet every day. This can be, for example, a glass of low-fat milk and 2 slices (50-60 g) of low-fat cheese. In this way, the calcium requirement can be easily covered.
The Federal Institute for Risk Assessment recommends that products that are intended to replace calcium-rich foods, such as a soy or oat drink as a milk substitute, do not add the (recommended) calcium additive to the level of the natural “counterpart” – here 120 mg calcium per 100 ml should exceed.
With a diet completely without dairy products, low-oxalate foods such as broccoli or calcium-rich mineral water should be used.
However, even the best calcium supply is of little use if there is a lack of vitamin D. Because vitamin D promotes the formation of a transporter that brings calcium from the blood into the cells. Therefore, in addition to a calcium-rich diet, it is just as important to regularly expose uncovered skin to the sun. This stimulates the body’s own production of vitamin D.
- With two to three glasses of milk or slices of cheese a day, you can do a lot to protect your bones.
- Calcium-rich cheeses are hard cheeses. Emmentaler, for example, contains 1372 mg/100 g, twice to three times as much as other types of cheese.
- Calcium-rich mineral waters (from 150 mg/l) are also well suited. Always look at the label for reliable information!
- Also, go outside for about 5 to 25 minutes a day to expose uncovered skin to the sun and get enough vitamin D!
