Calcium is an important nutrient that has many functions in the body. It is necessary for nerve function, to help our muscles contract and to assist with normal blood clotting. Calcium is more commonly known for its role in building and maintaining strong teeth and bones. It helps to prevent 'thinning' of the bones (osteoporosis). Making sure we have enough calcium will help to maintain bone strength and reduce the amount of bone that is lost as we age. It is the most abundant mineral in the body and because we can't make it, we need to consume a diet rich in calcium.
How much calcium do we need?
Adults over the age of 18 years need around 700 mg of calcium per day. There are other circumstances where more calcium is required. This may be if you:
- Are aged 9-18 years (1300 mg). Children aged 4-8 years need about 800 mg per day.
- Are breast-feeding (1250 mg).
- Have coeliac disease or Crohn's disease or ulcerative colitis (1000-1500 mg).
- Are a postmenopausal woman or man over 55 years old (1200 mg).
- Have 'thinning' of the bones (osteoporosis) (1000 mg).
You also need to make sure you are getting enough calcium if you have low calcium levels in the blood (hypocalcaemia) or are taking steroids. One of the side-effects of taking steroid tablets in the long term (for three months or more) is an increased risk of developing osteoporosis. This is known as steroid-induced osteoporosis.
There is some evidence that sodium in the diet, generally in the form of salt, can increase calcium loss from the body. It is generally a good idea to reduce dietary sodium, and certainly if you are trying to make sure your body gets plenty of calcium, it would be sensible to cut down on salt.
If you are on additional treatment for osteoporosis, such as alendronic acid then it is particularly important that you are eating enough calcium, as these treatments will not work if your calcium intake is too low.
People who are taking high doses of calcium supplements may increase their risk of heart disease but there is no association of increased risk with a diet which is naturally high in calcium.
What foods contain calcium?
The most well-known sources of calcium are milk and dairy products. However, calcium is also found in many other foods. This includes fish with edible bones such as tinned salmon, green leafy vegetables, nuts, seeds and fruits.
Some food manufacturers also enrich food products with calcium by adding it to certain foods - for example, in soya milk, orange juice, cereals and breads. In the UK, all wheat flour except wholemeal must be fortified with calcium.
Milk and dairy sources of calcium
|Milk (any type)||200 ml||240 mg|
|Yoghurt||125 g||200 mg|
|Cheddar cheese||30 g||216 mg|
|Soft cheese triangle||15 g||100 mg|
|Cottage cheese||100 g||73 mg|
|Rice pudding||200 g||180 mg|
|Ice cream||60 g (one scoop)||78 mg|
|Custard||120 ml||150 mg|
Non-dairy sources of calcium
|Sardines||100 g (four sardines)||410 mg|
|Pilchards||100 g (two pilchards)||340 mg|
|Haddock||150 g fillet||150 mg|
|Baked beans||220 g (one half of a large can)||100 mg|
|Enriched soya/rice milk||200 ml||240 mg|
|Enriched orange juice||250 ml||300 mg|
|Tofu||100 g||500 mg|
|Spring green||100 g||200 mg|
|Spinach||100 g||150 mg|
|Watercress||50 g||75 mg|
|Broccoli||50 g||30 mg|
|Okra||50 g||130 mg|
|Kale||50 g||65 mg|
|Chickpeas||100 g||45 mg|
|Almonds||15 g||35 mg|
|Brazil nuts||15 g||26 mg|
|Sesame seeds||one tablespoon||160 mg|
|Dried figs||60 g (three figs)||150 mg|
|Calcium-enriched bread||Two slices (80 g)||300 mg|
|Currants||100 g||93 mg|
How much calcium do I eat?
There are web pages and apps which will help you add up the calcium in your diet to make sure you are getting as much as you need. Details of several are given in the 'Further reading' section below.
If you find it difficult to get enough calcium from your diet - for example, if you are a vegan who is unable to tolerate soya - calcium supplement tablets are available at supermarkets and chemists.
Why is vitamin D important?
Vitamin D is needed for the body to absorb calcium effectively. Unlike other vitamins, we do not need to get vitamin D from food. Most of the vitamin D we have is made by our own bodies. It is made in the skin by the action of sunlight. This is a good thing because most foods contain no, or very little, vitamin D naturally. Foods that contain vitamin D include:
- Oily fish (such as sardines, pilchards, herring, trout, tuna, salmon and mackerel).
- Fortified foods (this means they have vitamin D added to them) such as margarine, some cereals, infant formula milk.
Public Health England recommends that everyone should take a vitamin D supplement of 10 micrograms (mcg) daily during the winter. Some people are at greater risk of vitamin D deficiency; therefore, a routine vitamin D supplement all year round is recommended. This includes:
- All pregnant and breast-feeding women should take a daily supplement containing 10 mcg of vitamin D.
- All babies and young children aged 6 months to 5 years should take a daily supplement containing vitamin D in the form of vitamin drops. However, those infants who are fed infant formula will not need vitamin drops until they are receiving less than 500 ml of infant formula a day, as these products are fortified with vitamin D. Breast-fed infants may need to receive drops containing vitamin D from 1 month of age if their mother has not taken vitamin D supplements throughout pregnancy.
- People aged 65 years and over should take a daily supplement containing 10 mcg of vitamin D.
- People who are not exposed to much sun or who have darker skin should also take a daily supplement containing 10 mcg of vitamin D.
Did you find this information useful?
- Management of osteoporosis and the prevention of fragility fractures - A national clinical guideline; Scottish Intercollegiate Guidelines Network - SIGN, (March 2015)
- Calcium Calculator; International Osteoporosis Foundation
- Calcium Calculator; Centre for Genomic and Experimental Medicine
- Steps to estimate your calcium intake; National Osteoporosis Foundation
- Dietary Calcium and Health; British Nutrition Foundation
- Advice on Vitamin D; Public Health England, July 2016
- Stransky M, Rysava L; Nutrition as prevention and treatment of osteoporosis. Physiol Res. 2009 58 Suppl 1:S7-S11.
- Sunyecz JA; The use of calcium and vitamin D in the management of osteoporosis. Ther Clin Risk Manag. 2008 Aug 4(4):827-36.
Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. Patient Platform Limited has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.