What is calcium?

The average adult’s weight is made up of about 2% calcium. Most of this is found in the skeleton and teeth - the rest is stored in the tissues or blood. Calcium is vital for healthy teeth and bones. It also plays a crucial role in other systems of the body, such as the health and functioning of nerves and muscle tissue.

Good sources of calcium include dairy foods like milk, yoghurt and cheese, and calcium-fortified products, such as some plant-based milks (for example, soy milk and rice milk) and breakfast cereals.

People at different life stages need different amounts of calcium - young children, teenagers and older women all have greater than average requirements.

According to the most recent National Nutrition and Physical Activity Survey of 2011-12:

  • Over half of all Australians aged 2 years and over consume inadequate levels of calcium from food sources.
  • Females are less likely to have adequate intakes of calcium than males.
  • 73% of females consume less calcium than recommended.
  • 51% of males consume less calcium than recommended.

It is much better to get calcium from foods than from calcium supplements. Be guided by your doctor about whether you need additional supplements. Too much calcium from supplements may cause other health problems.


Role of calcium in the body

Calcium plays a role in:

  • strengthening bones and teeth
  • regulating muscle functioning, such as contraction and relaxation
  • regulating heart functioning
  • blood clotting
  • transmission of nervous system messages
  • enzyme function.


Calcium and dairy food

Australians receive most of their calcium from dairy foods. If milk and milk-based foods are removed from the diet, this can lead to an inadequate intake of calcium. This is of particular concern for children and adolescents, who have high calcium needs.

Calcium deficiency may lead to disorders like osteoporosis, a disease in which bones become fragile and brittle later in life. Osteoporosis affects both men and women.


Too little calcium can weaken bones

If not enough calcium is circulating in your blood, your body will use hormones to reduce the amount of calcium your kidneys excrete in your urine. If not enough calcium is absorbed through the gastrointestinal tract, calcium will be taken from the bones.

If your dietary intake of calcium is constantly low, your body will eventually remove so much calcium from the skeleton that your bones will become weak and brittle.