Why is calcium important?

Calcium is essential for building and maintaining healthy bones throughout life. Calcium combines with other minerals to form hard crystals giving bones strength and structure. Almost 99% of the body’s calcium is found in the bones.

A small amount of calcium is absorbed into the blood and used for the healthy functioning of the heart, muscles, blood and nerves. Bones act like a calcium bank. If there is not enough calcium in your diet the body will take what is needed from your bones for use in other parts of the body. If this happens your bone density (bone strength) will gradually decline and you may be at risk of developing osteoporosis.

How much calcium is recommended?

Australian dietary calcium recommendations vary according to age.

LifestageAgeRecommended IntakeGuidance
Children1-3 years500 mg per dayGrowing bones require daily calcium intake. Daily dietary recommendations increase as children grow.
Children4-8 years700 mg per dayGrowing bones require daily calcium intake. Daily dietary recommendations increase as children grow.
Girls & Boys9-11 years1,000 mg per dayGrowing bones require daily calcium intake. Daily dietary recommendations increase as children grow.
Teenagers Girls & Boys12-18 years1,300 mg per dayCalcium is essential during the growth spurt. Peak bone mass is achieved by early twenties and 40% is acquired during puberty.
Adults19 years +1,0000 mg per dayAdequate calcium intake maintains bone strength.
Older AdultsWomen 50 years +1,300 mg per dayDaily recommendation increases as calcium is less e!ectively absorbed from the intestine and more can be lost through the kidneys.
Older AdultsMen 70 years +1,300 mg per dayDaily recommendation increases as calcium is less e!ectively absorbed from the intestine and more can be lost through the kidneys.

Excessive calcium intake is not recommended. If calcium supplementation is used it should only form part of daily requirements.

Calcium and food

The best way to achieve recommended calcium intake is to eat a diet rich in calcium. Calcium content in food varies so it is important to consume ‘calcium rich’ foods. Half of all Australian adults do not achieve their daily recommended intake of calcium. It is easy to add calcium to your diet by focusing on food groups which contain higher levels of calcium.

Food typeExamplesCalcium range (mg per serve)
DairyMilk, cheese, yogurt150 – 305 mg per serve
SeafoodTrout, snapper, mussels, oysters, prawns, canned sardines or salmon35 – 300 mg per serve
VegetablesCucumber, kale, silverbeat, chinese cabbage, broccoli rocket, watercress, bok choy, leeks59 - 250 mg per serve
Nuts & seedAlmonds, brazil nuts, hazelnuts, walnuts, sesame seeds, tahini paste28 – 75 mg per serve
FruitsOrange, strawberries, figs, kiwi fruit, dates16 - 95 mg per serve
OtherEggs, calcium-set tofu, canned chickpeas or soybean21 – 105 mg per serve
MeatPork chop, chicken21 – 105 mg per serve
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Do we absorb all the calcium we eat?

Not all the calcium we consume is absorbed. A small amount of calcium will be lost and excreted from the body which is normal. This is factored into the recommended intake for your age.

Other factors can impact calcium absorption and should be discussed with your doctor, for example:

  • Low vitamin D levels
  • Excessive caffeine and alcohol intake
  • Certain medical conditions (for example coeliac disease, kidney disease)

Calcium supplements

It is best to obtain calcium from your diet. However when adequate calcium intake is not possible a supplement may be required as directed by your doctor or pharmacist. Healthy Bones Australia recommends supplement doses in the range of 500-600 mg daily when required. This is considered safe and effective.

The most common types of calcium supplements are calcium carbonate, calcium citrate or hydroxyapatite. Supplements are available as oral tablets, effervescent tablets or soluble powder. Calcium supplements are usually well tolerated.

Calcium supplements are sometimes combined with vitamin D, as adequate vitamin D levels are important to assist the absorption of calcium in the body. Take supplements as directed and talk to your doctor or pharmacist if you have any queries.

Diagnosed osteoporosis and calcium.

Calcium is essential for supporting your bone health. For people with diagnosed osteoporosis calcium alone is not sufficient, osteoporosis medication is generally required as directed by your doctor. It is common practice for doctors to prescribe calcium supplementation to accompany osteoporosis medication. Adequate calcium intake throughout adult life helps support bone health but may not prevent osteoporosis as other factors can negatively impact your bone health. See risk factors.