Every child is taught from an early age how important calcium is for strong bones and healthy teeth. But why do we need calcium at all and what influence does it have on our body?
We answer these and many other questions in our calcium test 2021. We also present the most popular calcium products and show you different ways to supply your body with calcium.
We also answer important questions about the dose of the food supplement, the price and which foods are particularly rich in calcium. We also tell you what consequences a calcium deficiency has for your body and how you can quickly and safely recognise a deficiency.
- 1 Weekly newsletter with the best personal finance tips
- 2 The most important facts
- 3 The Best Calcium: Our Picks
- 4 Guide: Questions you should ask yourself before buying calcium
- 4.1 What influence does calcium have on the body?
- 4.2 How does calcium deficiency develop?
- 4.3 How does calcium deficiency manifest itself?
- 4.4 Who should supplement calcium?
- 4.5 Can an additional supply of calcium have side effects?
- 4.6 Can you overdose on calcium?
- 4.7 What are the symptoms of a calcium overdose?
- 4.8 In what doses is calcium available?
- 4.9 What should you consider when taking calcium?
- 5 Decision: What types of calcium are there and which one is right for you?
- 6 Buying criteria: You can compare and evaluate calcium based on these factors
- 7 Facts worth knowing about calcium
The most important facts
- Calcium is the substance that is most abundant in the human body. The disadvantage is that there is no endogenous calcium. It must therefore be supplied from the outside.
- The four most common calcium components are calcium carbonate, calcium citrate, calcium lactate and calcium gluconate. The first two substances are very popular because of their effectiveness.
- A lot of calcium is already absorbed through everyday food. Calcium supplements are therefore usually more suitable for people with calcium deficiencies due to illness, allergy sufferers or athletes.
The Best Calcium: Our Picks
Guide: Questions you should ask yourself before buying calcium
What influence does calcium have on the body?
However, the body's own calcium does not exist - it must be sufficiently absorbed from external sources. Together with other substances, calcium is involved in many processes that are vital for the human body.
Calcium is the fourth of 13 factors in blood clotting. Furthermore, it is indispensable for muscle contractions, as well as for the transmission of impulses from nerves and muscles. It also influences the acid-base balance of the blood and thus regulates its pH value.
The influence on the cardiovascular system in this context, however, is to be classified as rather minor. A significantly higher effect can be achieved through the intake of vitamin D. (1)
How does calcium deficiency develop?
To be able to absorb calcium properly, you need vitamin D - but only 40 percent of Germans have their needs met. The result is a body that is undersupplied in both calcium and vitamin D.
Certain diseases can hinder the absorption of calcium. An insufficient amount of calcium in the blood count can, conversely, indicate these diseases (pancreatitis, hormone disorders, kidney and thyroid diseases).
Treatment with certain medicines (e.g. cortisone, diuretics) can inhibit calcium absorption or take up significantly more calcium than normal consumption.
Resorption: Uptake of substances into the cell interior.
How does calcium deficiency manifest itself?
Especially in older people, calcium deficiency also occurs due to age. Accompanying symptoms can be increased bone loss as well as a greater susceptibility to fractures. (2)
Based on the other processes in the body in which calcium is involved, the muscles can be affected. This manifests itself in tremors and cramps. Calcium deficiency also affects appearance:
Fingernails become brittle, skin and hair appear brittle and dull. Many of these symptoms can signal calcium deficiency. But they do not have to. It is always advisable to consult a doctor in case of complaints of any kind.
Genetic conditions can be deceptive in this context. Even in the case of normal calcium levels, a predisposition to elevated serum calcium levels may not provide increased protection against possible fractures. (3)
Who should supplement calcium?
People who cannot absorb calcium from natural sources (for example, those who are lactose intolerant or vegans) are in a similar position. The same applies to people with digestive disorders (for example, IBS, celiac disease) that prevent or hinder the absorption of calcium.
Animals also need calcium, especially for their bones and teeth. For this reason, preparations have been developed to meet the needs of four-legged friends even better than conventional calcium preparations for humans.
Long-term treatment with corticosteroids (for example, in asthma, eczema, epilepsy) can lead to bone loss; here, too, an additional calcium supplement can be beneficial. In the form of a butyrate, calcium can also improve body weight gain. (5)
You usually get enough calcium from a balanced diet. Calcium supplements are only necessary in certain cases and ideally in consultation with a doctor.
Can an additional supply of calcium have side effects?
In the study in question, the mineral water from Bella Fontains contained 300 times the amount of calcium of the water from Rheinfels Quelle. From 150mg/l, a mineral water can be declared as containing calcium.
The maximum amount of daily calcium that can be tolerated by adults is 2,500 milligrams. As long as you do not significantly exceed this daily requirement, no side effects will occur.
The risks of cardiovascular diseases, which are predicted in connection with calcium intake through supplements, could not be clearly proven. (6)
Can you overdose on calcium?
Excessive intake through supplements increases it. The reason for this is additional substances such as phosphates, which are found in some foods and are important to balance the calcium level in the blood.
A calcium overdose can usually only occur together with an excess of vitamin D. This substance promotes calcium absorption. This substance promotes the absorption of calcium.
What are the symptoms of a calcium overdose?
- Kidney stones
- High blood pressure
- Heart problems
Claims that the heart arteries are clogged in this context have not been substantiated. (7)
In what doses is calcium available?
What should you consider when taking calcium?
You can take calcium citrate at any time. You do not need stomach acid for absorption. Calcium carbonate, on the other hand, is better taken outside of meals. However, if you have excess stomach acid (manifested, for example, by heartburn), it can give you a feeling of relief.
Some medications require a two- to three-hour waiting period before calcium can be resumed. These include, for example, medicines for high blood pressure or hypothyroidism. Antibiotics are interfered with by one of the main sources of natural calcium (milk) and should not be taken at the same time.
You can absorb a maximum of 500 milligrams of calcium per meal. Taking in a lot of calcium at once is therefore of little use. It is advisable to take calcium over the course of the day. Prolonged high doses taken once a day can lead to heart disease or vascular calcification, according to one study.
Regardless of your needs, you should avoid a daily dose of more than 2000 milligrams at all costs. The side effects mentioned above can be triggered or intensified. (8)
Decision: What types of calcium are there and which one is right for you?
Calcium is found in many forms in food and nature. The four most common types for supplements are:
- Calcium carbonate
- Calcium citrate
- Calcium lactate
- Claicum gluconate
Each component has different properties. It is important to know about these to find the right type of calcium for you. Often the four types share certain characteristics.
Some are unique due to the way they are produced and their composition. To help you decide, we have provided an overview of the advantages and disadvantages of each type of calcium.
Calcium carbonate is suitable for you if you also suffer from iodine deficiency, have an excess of gastric acid or attach importance to consuming products of natural origin.
Calcium carbonate can also be synthesised through the chemical reaction of calcium ions with carbonate ions. At 40 percent, it contains the highest proportion of calcium of all types. If you have an increased amount of stomach acid, calcium carbonate can simply be mixed with a little citric acid.
Calcium citrate, on the other hand, contains no additional iodine and has a positive effect if you produce too little stomach acid. The body does not need stomach acid when taking calcium citrate.
However, it is only artificially produced from citric acid. Some of the preparations have a slightly sour taste. At 21 per cent, it has the second-highest proportion of pure calcium.
Calcium lactate neutralises stomach acid and its high solubility makes it suitable for you if you suffer from digestive disorders that prevent or hinder calcium absorption.
It is produced exclusively through the chemical modification of lactic acid. The calcium content of calcium lactate is 12 percent. It is sometimes used to fortify fruit juices with calcium.
Calcium gluconate is also highly soluble and is often used in infusions in emergency medicine. It is produced from gluconic acid in the laboratory. It has a calcium content of nine percent and is often found together with phosphates and fluorides in preparations that treat osteoporosis.
Bioavailability: How quickly a substance can be absorbed by the body.
Buying criteria: You can compare and evaluate calcium based on these factors
With so many calcium supplements available in pharmacies, drugstores and other retailers, it can be difficult to make the right choice. However, if you know which criteria to use as a guide, individual selection becomes easy and the quantity of products an advantage. The criteria we have compiled include:
- Quantity of preparations
- Type of calcium component
- Dosage form
- Calcium concentration per preparation
- Vegetarian/vegan concerns
What these points mean and what you should pay particular attention to can be found in this section.
Quantity of preparations
Calcium supplements are available in different quantities, depending on the manufacturer and your needs. For people who only take calcium supplements for a short time, products of ten or more are recommended. Products with such small quantities can be found in most drugstores and discounters.
Packs of up to 600 supplements are usually intended for people who need to take calcium because of illnesses (for example, osteoporosis). These supply packs are designed for a span of two to three months and often require a prescription.
Type of calcium component
We have already listed the advantages and disadvantages of the four most common components above. Most products that are available without a prescription contain calcium citrate or carbonate.
According to several studies (1985, 1988, 1999), calcium citrate is the better source of calcium. In the tests carried out, men and women were equally used as test subjects. They took calcium tablets with the same dose of calcium carbonate or citrate. The proportion of calcium in the urine was higher for each person after taking calcium citrate.
A study from 2014 came to a different conclusion, but the problem with this study is that calcium citrate was taken in the form of two tablets with 500 grams of calcium each and calcium carbonate in powder form with 1,000 grams of calcium.
Since the body processes these two forms differently, the maximum that can be concluded is that calcium carbonate is better absorbed at a high dose in powder form.
However, since calcium carbonate is mainly obtained from the Sango sea coral, it naturally contains additional magnesium. The ratio of calcium to magnesium is approximately two to one.
The influence of magnesium on the body (especially in combination with calcium) can be found in the section on additives. Sea coral also contains over 70 trace elements such as iron and iodine. Despite these differences, both forms have a high bioavailability.
Therefore, it makes sense to decide according to the advantages and disadvantages that the two components additionally bring with them. Calcium citrate is not automatically the better source of calcium for everyone. Calcium carbonate has the following advantages over calcium citrate, which you should also take into account:
- Film-coated tablets to swallow
- Chewable tablets
- Coated tablets
- Effervescent tablets
Film-coated tablets and capsules are the quickest ways to deliver calcium. By swallowing, they dissolve in the stomach and the active ingredients are transported directly through the mucous membrane to the appropriate sites.
It should be noted that in addition to calcium, these products often contain fillers such as cellulose or coatings such as shellac. They ensure that the tablets or capsules reach the stomach in their solid form and are only dissolved there.
If you are uncomfortable swallowing, there are chewable tablets or coated tablets options. These are usually coated with a layer to make them more palatable to eat. Since the coatings are meant to be sweet, sugar, honey or flavourings are often found among the ingredients. These options are not recommended for people who live a low-sugar lifestyle or are on a diet.
Of course, you can also avoid solid preparations altogether and dissolve effervescent tablets or calcium powder in water. Effervescent tablets often contain sweeteners, dextrose, anti-caking agents and other additives to ensure complete dissolution in water and an acceptable taste.
Calcium powder has the advantage of not requiring any other substances to enter the body in a certain form. Fillers or flavourings are completely omitted. In addition, the dosage is more individual, but also more complicated. It can quickly happen that the dosage is too high or too low.
The effect or absorption capacity is not affected by the form. What is much more important is the type of calcium contained in the preparations. It is always advisable to look at the package leaflet before buying.
Calcium concentration in a preparation
Most people cover their daily calcium requirements as far as possible with their natural diet. If you consume more calcium than the DGE reference value (about 1,000 milligrams per day), this has no further consequences for your body.
However, studies show that long-term intake of calcium supplements with a high dose (over 1,000 milligrams per supplement) can lead to precursors of heart disease and even heart attacks. (9) In addition, the calcium can settle in the vessels and lead to calcification.
According to a study by the Federal Institute for Risk Assessment, a dose of 500 milligrams per preparation is sufficient. Since the body cannot absorb more than 500 milligrams of calcium per intake, this is quite sufficient.
The recommended daily dose of calcium preparations (500 milligrams) is below the DGE value. However, this is not a big deal because you usually already get calcium from your diet. If you are taking a higher daily dose, it is a good idea to spread it out over the day.
Few calcium supplements contain only calcium. Our products also contain other components. Vitamin D, vitamin K12 and magnesium are often partners of calcium in many combination preparations. This is because all substances are dependent on each other in order to be properly utilised in the body. But the addition of other substances is not always advantageous.
- Necessary for the absorption of calcium.
- 500 mg calcium requires approx. 1000 to 2000 IU (International Unit, commonly used for vitamin D).
The more vitamin D you have in your body, the more calcium is absorbed. There is a danger of calcium excess. Therefore, it is not always advisable to take vitamin D at the same time as calcium.
- Needed for optimal distribution of calcium to all necessary sites.
- If there is an undersupply of vitamin K2, calcium is deposited in the kidneys or arteries and can lead to calcification there.
- Required amount depends on vitamin D: for an intake of 2,000 IU vitamin D, about 100 macrograms of K2 are recommended.
- Required for activation of vitamin D
- Functions similar to calcium in the body (stimulus transmission to muscles and nerves)
- Daily requirement: 300 to 400 milligrams
Both calcium and magnesium enter the blood through the same channel. The release of excess calcium is always at the expense of magnesium and vice versa. If you already consume the recommended daily amount of magnesium, you do not need it in addition to your calcium supplements.
Vegetarian / vegan concerns
Most calcium intake comes from food. People who eat a vegetarian or vegan diet, or who suffer from certain allergies, may have problems getting the right amount of calcium.
Calcium supplements themselves usually do not contain animal products and can be taken by vegetarians without hesitation. Sometimes, however, preparations in capsule form contain gelatine. Calcium carbonate is mainly obtained from the Sango sea coral.
Sediments or remains of the skeleton are used, which the coral rejects on its own. Often vegans can be reassured here because the living coral is not damaged. However, this is not always guaranteed. To be on the safe side, it is recommended for vegans to claim another calcium source such as calcium citrate.
In connection with an equivalent bioavailability of calcium, the extent of mineralisation of mineral water does not play a role. Thus, you are not dependent on milk in this context. (10)
Facts worth knowing about calcium
How do you absorb calcium naturally?
You get most of the calcium you need every day from the food you eat. The table below lists some of the foods you probably already consume in various amounts in your daily life.
|Product||Calcium per 100 g|
|Product||Calcium per 100 g|
|Leaf spinach||99 mg|
|Product||Calcium per 100 g|
|White beans||105 mg|
|Product||Amount per 100 g|
Dairy products myth: Not all are healthy. A higher calcium content does not automatically mean a better source of calcium. Milk, for example, does not provide any other substances that support your bones. Cabbage, on the other hand, contains magnesium and vitamin C in addition to a comparable calcium content.
Although vegans and lactose-intolerant people can benefit from calcium supplements, getting enough natural calcium is not impossible.
Calcium, calcium, calcium?
Calcium is the spelling in chemistry. Calcium, on the other hand, is the most commonly used colloquially, especially in medicine. Both are correct and can be used. Calcium is sometimes still found on the internet or in literature, but is outdated. Calcium is incorrect and cannot be found in any dictionary.
Picture credits: mehrshadr / unsplash.com
Douglas C. Bauer, M.D. 2014. The new england journal of medicine. From the Departments of Medicine and Epidemiology and Biostatistics, Univer-sity of California, San Francisco, San Francisco. Address reprint requests to Dr. Bauer at the University of California, San Francisco, 185 Berry St., Suite 5700, San Francisco, CA 94105, or at [email protected]
Cerani A, Zhou S,, Forgetta V, Morris JA,, Trajanoska K, Rivadeneira F,, Larsson SC, Michaëlsson K, Richards JB. 2019. Lady Davis Institute, Jewish General Hospital, McGill University, Montréal, Québec, Canada.
Department of Epidemiology, Biostatistics and Occupational Health, McGill University, 3755 Côte Ste-Catherine Road, Suite H-413, Montréal, Québec, H3T 1E2, Canada.
Department of Human Genetics, McGill University, Montréal, Québec, Canada.
Department of Internal Medicine, Erasmus MC, University Medical Center, Rotterdam, Netherlands.
Department of Epidemiology, Erasmus MC, University Medical Center, Rotterdam, Netherlands.
Unit of Nutritional Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
Department of Surgical Sciences, Uppsala University, Uppsala, Sweden.
Lady Davis Institute, Jewish General Hospital, McGill University, Montréal, Québec, Canada [email protected]
Kelvin Li, Xia-Fang Wang,, Ding-You Li, Yuan-Cheng Chen, Lan-Juan Zhao, Xiao-Gang Liu, Yan-Fang Guo, Jie Shen, Xu Lin, Jeffrey Deng, Rou Zhou, and Hong-Wen Deng. 2018. Clin Interv Aging. 2018; 13: 2443–2452.
Published online 2018 Nov 28. doi: 10.2147/CIA.S157523
Abd El-Wahab A, Mahmoud RE, Ahmed MFE, Salama MF. 2019. Department of Nutrition and Nutritional Deficiency Diseases, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt. Department of Hygiene and Zoonoses, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt.
Department of Biochemistry, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt.
Chan Soo Shin and Kyoung Min Kim. 2015. Endocrinol Metab (Seoul). 2015 Mar; 30(1): 27–34.
Published online 2015 Mar 27. doi: 10.3803/EnM.2015.30.1.27
Department of Medicine, Harvard Medical School and Institute for Aging Research, Hebrew SeniorLife, Boston, MA, USA. [email protected] Am J Clin Nutr. 2012 Dec;96(6):1274-80. doi: 10.3945/ajcn.112.044230. Epub 2012 Nov 7.
Mark A. Plantz; Khaled Bittar. 2019. Institute of Medicine of the National Academies.
Bolland MJ, Avenell A, Baron JA, Grey A, MacLennan GS, Gamble GD, Reid IR. 2010. Department of Medicine, Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92 019, Auckland 1142, New Zealand. BMJ. 2010 Jul 29;341:c3691. doi: 10.1136/bmj.c3691.
Greupner T, Schneider I, Hahn A. 2017. a Institute of Food Science and Human Nutrition, Leibniz University Hannover , Hannover , Germany.