In brief
The most abundant mineral in the body. Almost all of it is stored in bones and teeth, and the rest circulates in the blood for your heart, muscles and nerves.
- Calcium supplements can interact with certain medicines, so seek your doctor's advice before taking them.
- Calcium-rich foods and supplements reduce iron absorption, so have them between meals.
- Some medicines, such as corticosteroids, are a risk factor for osteoporosis, according to healthdirect.
How it works
Calcium combines with other minerals, such as phosphate, to give bones structure and strength. If you do not get enough from food, your body takes the calcium it needs from your bones, and over time this can lead to loss of bone density and osteoporosis.
healthdirect lists 1,000 mg a day for adults aged 19 to 50, rising to 1,300 mg for women over 50 and men over 70. Good sources include dairy foods, canned fish such as sardines or salmon, firm tofu, green leafy vegetables and almonds. To absorb calcium, your body needs vitamin D.
Food sources
- Milk, yoghurt and cheese
- Canned fish such as sardines or salmon
- Firm tofu
- Green leafy vegetables
- Almonds
From the AskBioMap food guide:
Connections
3 connections on the map. Select a topic to read its page.
Calcium can lower
Calcium-rich foods and calcium supplements reduce iron absorption, so have them between meals.
Sources: healthdirect Australia, Foods high in iron; NIH Office of Dietary Supplements, Iron fact sheet for consumers
Calcium is needed for
Almost all calcium in the body is stored in bones and teeth.
Source: NIH Office of Dietary Supplements, Calcium fact sheet for consumers
Calcium is linked with
If your diet is low in calcium, your body takes calcium from your bones, which over time can lead to osteoporosis.
Sources: healthdirect Australia, Calcium; NIH Office of Dietary Supplements, Calcium fact sheet for consumers
Sources
Each connection above names its own source. See every source AskBioMap uses.
Summarised from healthdirect and the NIH Office of Dietary Supplements. Sources read on 13 and 16 October 2026. General education only, not medical advice. Spotted a mistake? Please tell us through the HuBu-Intel contact page.