Dizziness, numbness in the limbs, cramps and joint pains - these are just some of the symptoms of calcium deficiency This mineral plays an important role in the body and an insufficient supply can lead to serious consequences - especially in the youngest. How do I get calcium from my diet? What should I avoid combining it with? What symptoms should we be alert to? Here is what you need to know about calcium.

The role of calcium in the body. What is it and what properties does it have?

Calcium is a macronutrient (its daily requirement is 800 mg) essential for the body to function properly. Approximately 99% of the calcium present in the adult body is found in the skeletal system. It is therefore not surprising that its influence on the proper functioning of the musculoskeletal system is mentioned most often. However, this mineral has many tasks to perform - without it, many processes in the body are impossible.

Main functions of calcium in the human body

Calcium influences the function of various systems in the body - from the skeleton to the digestive and circulatory systems. It is responsible for, among other things:

• building functions (it is included in the composition of bones and teeth, blood vessels and hair and nails),
• motor functions (helps muscles to function optimally by contributing to the regulation of their contractions, among other things),
• proper functioning of digestive enzymes,
• nerve transmission,
• maintaining normal energy metabolism,
• hormonal regulation,
• the self-regulation of the body's biological processes (homeostasis) contributing, among other things, to normal blood clotting,
• carrying out cell division and specialisation ^[1].

Calcium-rich products: the importance of a balanced diet

The importance of a varied diet is invaluable, and it largely influences how we feel on a daily basis. Sources of calcium should therefore be sought first and foremost on the plate - the body will certainly repay the favour with efficient functioning.

Where is calcium found? Good sources of this macronutrient are:

• dairy products (e.g. yoghurt, milk, cream, cheese),
• fortified foods and drinks (e.g. soya drink, orange juice, breakfast cereals),
• fish (e.g. canned sardines, salmon),
• vegetables (e.g. broccoli, kale, Chinese cabbage, turnip greens),
• legumes (e.g. soya) ^{[2, 3]}.

What affects the bioavailability of calcium?

Calcium deficiencies are very common - found in all age groups and in many parts of the world. This is mainly due to a lack of a varied diet on a daily basis. It can also be linked to a lack of awareness of what makes calcium better or worse absorbed. It is good to know that inappropriate food combinations or prolonged intake of certain foods in large quantities can contribute to reduced calcium absorption. However, this works both ways - so following certain dietary rules can help the absorption of this macronutrient. It is important to realise that health status or other biological factors also have a not insignificant impact on calcium bioavailability ^[1].

Calcium absorption depends on what you eat

An important issue to pay attention to when planning your diet is the absorption of calcium. This depends on the type of food we eat. It is important to know that certain compounds can affect the bioavailability of calcium and therefore reduce the effectiveness of the diet or supplements taken.

Dietary components that contribute to reduced calcium absorption

Ingredients and food habits that reduce calcium absorption include:

• a high-fibre diet - this is high in fibre (e.g. whole-grain products and fruit and vegetables) and phytates (e.g. nuts and cereal grains) and cellulose (e.g. cereal grains, legumes, kohlrabi);
• Oxalates - these include green leafy vegetables (e.g. spinach), as well as beans, rhubarb and coffee;
• Protein - consuming protein in excess can increase the excretion of calcium from the body;
• ethanol - alcohol intake (especially long-term) can reduce not only calcium absorption, but also the levels of vitamin D, which promotes proper calcium absorption ^{[1, 3]}.

Dietary components that increase the bioavailability of calcium

Calcium absorption can be increased by:

• Vitamin D - calcitriol has the function of regulating calcium absorption in the intestines;
• sugars - lactose as well as glucose and galactose (formed during the breakdown of lactose) act to increase calcium absorption ^{[1, 4, 5]}.

What biological factors can affect the bioavailability of calcium?

Body condition and ailments can also affect calcium absorption. Women during pregnancy and lactation have a greater need for this macronutrient. This increases intestinal absorption, so that calcium absorption can increase by up to 340%. A marked decrease in calcium absorption is observed in women and men over the age of 60. This is particularly a problem for postmenopausal women, who are at risk of frequent bone fractures - taking care of supplementation at this time therefore has a preventive effect that can reduce the symptoms of osteoporosis. Diseases of the digestive system can also adversely affect calcium absorption. These include celiac disease and malabsorption syndromes ^[1].

Calcium deficiency - symptoms that should arouse vigilance

Hypocalcaemia in adults - how to recognise it?

Hypocalcaemia, or calcium deficiency, does not always produce specific symptoms. It can go unnoticed - especially when it takes a chronic form or is at a low level. In many cases, however, the following symptoms may occur:

• muscle spasms,
• perioral numbness,
• tingling in the feet and hands,
• joint pains,
• blood clotting disorders (manifested, for example, by frequent bruising),
• dizziness,
• memory disorders,
• rapid fatigue,
• insomnia,
• allergies and rashes,
• susceptibility to fractures.

In the advanced stage of deficiency, neurological symptoms (e.g. the presence of depressed mood), paresthesias and seizures can be observed ^{[1, 2]}.

What are the effects of calcium deficiency in children and adolescents?

It is worth noting how important calcium is for children and young people. It is in this group of people (next to seniors) that an inadequate supply of the macronutrient can be particularly felt. Calcium deficiency in the youngest subjects puts them at risk of rickets and, as a consequence, of irreversible changes in the structure of the skeleton ^[2]. Inadequate calcium supply prevents the achievement of peak bone mass. In addition, children may struggle with skeletal deformities, early caries, excessive sweating, late teething and walking, and increased crying at night ^{[1, 2]}.

What are the risks of inadequate calcium supply in older people?

Older people - especially post-menopausal women - need to pay particular attention to the symptoms their body is sending out. The production of oestrogen is reduced during this period and this leads to a reduction in calcium absorption and an increase in calcium loss through the urine. Calcium deficiency is considered one of the main causes of osteoporosis. Hypocalcaemia has the effect of reducing bone strength, which increases the risk of fractures. The combination of calcium and vitamin D is the basis for the prevention and management of osteoporosis symptoms ^{[1, 2, 6 ]}.

Caution with supplementation. Excess calcium - symptoms

Hypercalcaemia, i.e. excess serum calcium, is relatively rare in healthy individuals - it is usually due to specific medical conditions in the body. However, it is worth knowing which symptoms to look out for - especially if you are taking large portions of calcium in the form of supplements. The following symptoms may indicate an excess of this macronutrient:

• poor muscle tone,
• weight loss,
• nausea,
• constipation,
• fatigue,
• polyuria,
• cardiac arrhythmias ^[2].

How do I know what my calcium requirements are?

The recommended daily allowance (RDA - Recommended Dietary Allowances, i.e. the average daily intake level that is sufficient to meet the nutrient requirements of healthy individuals) is determined by analysing the mineral intake and its loss through urine, faeces and sweat ^{[1, 2]}.  These values vary according to age, gender and other factors - such as health status. It is worth familiarising yourself with the official data so that you can consciously ensure an adequate supply of calcium - both from the diet and supplements.

Calcium requirements for different age groups are as follows:

• 1-3 years - 700 mg;
• 4-8 years - 1000 mg;
• 9-13 years - 1300 mg;
• 14-18 years - 1300 mg; the same values apply to pregnant and lactating women;
• 19-50 years - 1000 mg; the same values apply to pregnant and lactating women;
• 51-70 years - 1200 mg for women, 1000 mg for men;
• over 70 years - 1200 mg ^{[1, 2]}.

Are you taking medication? Find out which ones can interact with calcium

Anyone taking medicines should be aware of what contributes to their impairment and what causes adverse effects. It is important to know that calcium interacts with specific groups of medicinal products - which can lower or raise their concentration in the body. Therefore, it is often advisable to maintain an appropriate time interval between taking these two substances. Here is a list of examples of medicines that may interact with calcium: 

Download the list of interaction

Which calcium supplement should I choose? Well tested and highly bioavailable  

Calcium supplements are most commonly found on the market in the form of calcium carbonate or calcium citrate. It is the latter type that provides greater bioavailability. Studies have shown that citrate is absorbed approximately 22 to 27% better than carbonate ^{[2, 8]}. In addition, it has been shown that calcium citrate - significantly more than calcium carbonate - reduces markers of bone resorption in postmenopausal women ^[9]. Furthermore, carbonate causes more side effects associated with its intake. It can negatively affect the digestive system by causing bloating or constipation, for example ^[2]. The choice of citrate therefore proves to be more beneficial - both in terms of bioavailability and overall well-being.

Calcium Citrate, Powder 240 grams is a product that meets customer expectations. It contains a well-absorbed organic salt, so you can easily increase the effects of supplementation. Calcium from OSAVI comes in the form of a tasteless and odourless powder, so you can forget about unpleasant sensations when taking it every day. The product has no additives in its composition - it only contains calcium salts of citric acid. It is also gluten-free, lactose-free, sugar-free and soy-free, and suitable for vegetarians and vegans. 

The recommended daily serving of the product is 4.7 grams, which contains up to 960 mg of calcium (120% RWS). How can you provide it? Simply mix 3 scoops of powder in 200 ml of water or juice and drink the suspension immediately after preparation.  

Thanks to the powder form and the included measuring cup, you can adjust the amount of calcium supplied to suit you. Use the table provided to choose the portion of the supplement you prefer. 

Are you looking for support for the musculoskeletal system, or perhaps you want to improve your digestive processes? Calcium citrate powder 240 grams will be particularly useful for seniors, post-menopausal women (i.e. a group in which calcium deficiency and the risk of osteoporosis is very high), and people whose diet is particularly deficient in this mineral. 

[1] Theobald H.E. (2005). Dietary calcium and health. Nutrition Bulletin, 30: 237-277. https://doi.org/10.1111/j.1467-3010.2005.00514.x. 
[2] Calcium. Fact Sheet for Health Professionals. National Institutes of Health. Office of Dietary Supplements. Downloaded 27.02.2023 from https://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/.
[3] Miller G. D., Jarvis J.K. & McBean L. D. (2001) The Importance of Meeting Calcium Needs with Foods, Journal of the American College of Nutrition, 20:2, 168S-185S, DOI: 10.1080/07315724.2001.10719029.
[4] Kwak. H. S. et. al. (2012). Revisiting lactose as an enhancer of calcium absorption. International Dairy Journal; Volume 22, Issue 2, Pages 147-151. https://doi.org/10.1016/j.idairyj.2011.09.002.
[5] Wood R. et. al. (1987). Effects of glucose and glucose polymers on calcium absorption in healthy subjects. The American journal of clinical nutrition; 46(4). 699-701. DOI:10.1093/ajcn/46.4.699

[6] Gómez J.M.Q.et al. (2011). Calcium Citrate and Vitamin D in the Treatment of Osteoporosis. Clin. Drug Investig. 31, 285-298. https://doi.org/10.1007/BF03256927. 
[7] Drug Interactions Checker - For Drugs, Foods & Alcohol. Drugs.com. Prescription Drug Information. Downloaded 4.04.2023 from https://www.drugs.com/. [8] Sakhaee, Khashayar; Bhuket, Taft; Adams-Huet, Beverley; Rao, D. Sudhaker. (1999). Meta-analysis of Calcium Bioavailability: A Comparison of Calcium Citrate with Calcium Carbonate. American Journal of Therapeutics, 6(6):p 313-322. 
[9] Kenny A.M. et al. (2004). Comparison of the effects of calcium loading with calcium citrate or calcium carbonate on bone turnover in postmenopausal women. Osteoporos Int 15, 290-294 https://doi.org/10.1007/s00198-003-1567-0.