Latest Catalogue Calcium



Calcium is an essential mineral that is the most abundant type of mineral in the body.


About 99% of the body's Calcium is contained in the skeleton in the form of Calcium crystals. Calcium is very important for the formation of strong, healthy bones and for decreasing the risks of bone fractures and osteoporosis. Even after bone growth has stopped, there is a constant process of bone remodelling that takes place. Dietary Calcium is required throughout life to enable new bone to form. Calcium exists in the body fluids as a particle called an ion, which carries a small, positive electric charge. This property allows Calcium ions to conduct electrical impulses in nerve and muscle cells, which allow nerves to transmit signals in the body and allow the muscles of the body to contract.

Calcium is also essential for the contraction of the heart as well as for the release of certain hormones and other chemicals in the body. Among these chemicals are the neurotransmitters: specialised 'signal' chemicals that help the nerves throughout the body communicate with one another. Calcium is also an important part of many enzymes and other proteins in the body. Enzymes are special substances that speed up chemical reactions in the body. Calcium also assists in the blood clotting process.

The Calcium levels in the body are very tightly controlled by hormones as well as vitamin D. Very high Calcium levels in the body can cause Calcium toxicity, but this usually only occurs in certain diseases that decrease the ability of the kidney to secrete Calcium in the urine. High Calcium levels can be caused by an excess of vitamin D in the body, as this vitamin changes the metabolism of Calcium so its levels build up in the body. Milk-alkali syndrome is a syndrome where a person suffers Calcium toxicity that is caused by consuming large amounts of dietary Calcium while taking certain peptic ulcer medications to reduce the acidity of the stomach. This medication reduces the body's capacity to excrete calcium. Short-term, high Calcium levels in the body can cause loss of appetite, vomiting, abdominal pain, constipation, confusion, psychosis and even coma. Long-term effects of elevated Calcium levels include the formation of calcium-rich kidney stones.


Calcium deficiency can be caused by certain hormonal deficiency diseases, including hypoparathyroidism, as well as vitamin D deficiency, kidney disease, magnesium deficiency, diseases of the pancreas and other medical conditions. Symptoms and signs of Calcium deficiency include muscle cramps; osteoporosis; confusion; depression; psychosis; cataracts; poor sensation in the hands, feet, lips and tongue; involuntary muscle twitching; heart rhythm disturbances; dry and brittle nails and coarse hair.


Dairy products contain large amounts of Calcium that is in a form that is easily absorbed. Non-dairy sources of Calcium include tofu that is chemically set with Calcium, dried beans, kale, broccoli and bok choy.

There are various Calcium supplements available and these should generally be taken with vitamin D to improve the absorption of Calcium from the intestines. People with kidney disease are generally advised by their Doctor to take a supplement that prevents the absorption of phosphate, such as calcium carbonate.

The key factor to consider when selecting a Calcium supplement is the amount of elemental calcium the product contains. The term 'elemental Calcium' refers to the actual amount of Calcium in a supplement that is available for the body to absorb. Most Calcium supplements list the amount of elemental Calcium on the label. In some cases only the total weight of each tablet, in milligrams (mg), is listed. This is the weight of the Calcium, plus whatever it is bound to, such as carbonate, citrate, lactate or gluconate. Some of the types of Calcium supplements that are available include:

Advantages: best absorbed source, complete bone food containing a variety of minerals, amino acids and protein matrix like human bone, shown to increase bone density, may help to stop bone loss, better absorbed by people with poor digestive absorption than other forms of calcium.
Disadvantages: none.

Advantages: very well absorbed, reduced risk of kidney stones, well absorbed by those with poor digestive absorption.
Disadvantages: not a complete bone food.

Advantages: may promote bone mineralisation, well absorbed.
Disadvantages: not a complete bone food, lower level of elemental calcium, a high dose is required to provide enough calcium.

Advantages: well absorbed.
Disadvantages: not a complete bone food, may contain milk or yeast by-products. (Sourced from milk, sugar, starch or whey with calcium carbonate).

Advantages: cheapest form of calcium.
Disadvantages: not a complete bone food, malabsorbed by those with poor digestion, poor absorption in older people, it has an antacid effect that interferes with digestion. This type of Calcium is best taken with food to enhance absorption. Some calcium carbonate supplements may be sourced from oyster shells or coral, while others are sourced from limestone. These oyster shell and coral-based supplements are not suitable for a person with an allergy to shellfish. If the manufacturer cannot verify the source, choose a supplement containing another form of calcium, such as calcium citrate.

Advantages: contains multiple minerals needed for bone.
Disadvantages: may contain high levels of lead, arsenic and cadmium, some of the organic constituents are destroyed leading to reduced effectiveness.

Ask your Pharmacist which supplement is best for you.


The recommended dietary intake (RDI) for Calcium is 800 mg per day for adult males and 800 mg per day for adult females until the age of 54. Women over 54 years of age require 1000 mg of Calcium per day. Women who are pregnant require an additional 300 mg of Calcium per day and those who are breastfeeding require an extra 400 mg per day.