Contents

• Calcium requirements
• Calcium sources
• A few words about the absorption and bioavailability of calcium
• Calcium deficiency – hypocalcemia
• Calcium and vegans, vegetarians and people who avoid dairy products
• Calcium-fortified products

Calcium is probably the most talked-about element, and for good reason. It's responsible for many functions in the body, from bone formation to blood clotting to muscle contractions. Despite its fame, however, its deficiencies are relatively common, so it's worth knowing a little more about this extraordinary mineral to avoid its deficiencies.

Calcium (Ca) is present in the human body in amounts of 1000–1200 g, or about 1.5% of body weight. 99% of this is found in the bones, and to a lesser extent in the teeth and nails—mainly in the form of calcium phosphate. The remaining 1% is distributed throughout the body. It has many functions, including:

– Preservation of bone structure,

- is a component of teeth and nails,

– it is necessary for proper blood clotting, e.g. in cuts,

– is an activator or inhibitor of various enzymes,

– affects the proper function of nerve cells, e.g. muscle cramps,

– it is necessary for the proper functioning of the heart and vascular system,

- continuous participation in maintaining the body's homeostasis - regulation of inflammatory processes, reduction of cell membrane permeability,

- is important for lowering blood pressure.

Calcium requirement:

RDA – the recommended daily intake that covers the calcium needs of almost all people in a particular group is:

Children

1–3 years – 700 mg/day

4–9 years – 1000 mg/day

10–18 years – 1300 mg/day

Adult

19-50 years old – 1000 mg/day

51-year-old women and 66-year-old men and older – 1200 mg/day.

Calcium sources

Despite the fact that large amounts of calcium are contained, for example, in poppy seeds (1266 mg per 100 g of the product), almonds (239 mg per 100 g of the product), kale (157 mg/100 g of the product), these products are consumed in small amounts compared to dairy products. In addition, plant sources of calcium such as spinach (93 mg / 100 g of the product), in addition to a significant amount of calcium, also contain large amounts of oxalic or phytic acid, due to which the final amount of absorbed calcium is not so large. Therefore, when talking about sources of calcium, the most common thing you hear is that it is found in milk and dairy products. A certain amount of calcium can be supplied with drinking and mineral water.

Calcium in larger quantities is found in (values ​​are given per 100g/product):

– skimmed milk powder – 1404 mg,

– Poppy seeds – 1266 mg,

– Sesame – 975 mg,

– Edam cheese, fat-containing – 867 mg,

– Gouda cheese, fat – 807 mg,

– Cheddar cheese, full fat – 703 mg,

– Feta cheese – 500 mg,

– Processed cheese, fat – 367 mg,

– Tofu -350 mg,

Bones eaten) – 330 mg,

– Staropolanka water 290 mg,

– Almonds – 239 mg,

– Soybeans, dry seeds – 240 mg,

– Muszynianka water – 208 mg,

– dried figs -203 mg,

– Parsley – 193 mg,

– Hazelnuts – 186 mg,

– Natural yogurt – 170 mg,

– white beans – 163 mg,

– Kale – 157 mg,

– dried apricots – 13 mg,

– Pistachios 135 mg,

– Sunflower seeds – 131 mg,

– Goat milk – 130 mg,

– Cow’s milk 2% – 120 mg,

– Soy milk -120 mg,

– Wheat bran – 119 mg,

– Kefir – 103 mg,

– Swiss chard – 97 mg,

– Chives – 97 mg,

– Spinach – 93 mg,

– dried raisins – 78 mg,

– Savoy cabbage – 77 mg,

– Broccoli – 50 mg.

A few words about the absorption and bioavailability of calcium

The main site of calcium absorption is the small intestine, particularly the jejunum. Small amounts are absorbed in the large intestine. The absorption capacity of calcium from foods varies around 30% (minimum approximately 10% to maximum 40%). The effectiveness of calcium absorption is quite similar across foods. However, the final absorption of calcium from foods is influenced by the oxalate content during production or by consuming calcium-rich foods in the presence of oxalate-rich foods.

Calcium deficiency – hypocalcemia

For many years, various programs have been established to promote increased calcium intake, such as the "Drink Milk, You'll Be Well" campaign. Nevertheless, it is estimated that Poles still consume too little calcium during the day (approximately 60% of the recommended intake). The consequences of frequent calcium deficiency are the frequent diagnosis of osteoporosis, osteomalacia, or rickets, as well as short stature in children. Other symptoms of calcium deficiency include increased excitability, tetany, increased blood pressure, and neurological disorders. At the same time, it should be noted that chronic hypocalcemia can be asymptomatic.

The following are used to treat chronic hypocalcaemia:

- calcium carbonate,

– Calcium acetate,

- Vitamin D

During the use of calcium supplementation, it is advisable to regularly check serum and urine calcium levels.

Calcium and vegans, vegetarians and people who avoid dairy products

It's not that it's impossible to ensure adequate calcium intake for vegans and vegetarians, or for people who avoid dairy products for various reasons. Plant-based products rich in calcium are consumed relatively rarely or in small quantities. Therefore, only people who pay close attention to their calcium intake can fully meet their calcium needs. Therefore, supplementation or increased attention to this element is often recommended for these individuals.

Too much calcium – hypercalcemia

Excess calcium is relatively rare and is usually the result of an overdose of vitamin D in children or calcium supplements in adults. Symptoms of too much calcium in the body include various types of urinary tract problems (urinary-base syndrome, kidney failure, kidney stones), as well as calcification of blood vessels and damage to organ structure. Hypercalcemia also increases the risk of cardiovascular disease and prostate cancer and impairs the absorption of other nutrients, especially magnesium, iron , and zinc.

Calcium-fortified products

Calcium-fortified products such as vegetable drinks, tofu, etc., are one of the solutions related to the common calcium deficiencies described above. Fortification involves adding an additional portion of calcium to the product in the form of an easily assimilated compound.

It should be noted that calcium does not dissolve in liquid products, such as soy drinks, but tends to settle at the bottom of the packaging. Therefore, if we have purchased a product based on its calcium enrichment, we must shake it before consumption to avoid throwing away all the valuable elements with the packaging instead of being consumed.