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 also helps to prevent against conditions such as 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 need around 700 mg of calcium per day. There are other circumstances where more calcium is required. This may be if you:
- Are breast-feeding (1250 mg).
- Have coeliac disease (1000-1500 mg).
- Are postmenopausal (1200 mg).
- Have 'thinning of the bones' (osteoporosis) (1000 mg).
You also need to make sure you are getting enough calcium if you have hypocalcaemia (low calcium levels in the blood) 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.
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, 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.
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|
|Brocolli||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|
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. A main source of vitamin D 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.
Some people are at greater risk of vitamin D deficiency; therefore, a routine vitamin D supplement is recommended. This includes:
- All pregnant and breast-feeding women: should take a daily supplement containing 10 micrograms of vitamin D.
- All infants (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 one 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 micrograms of vitamin D.
- People who are not exposed to much sun: should also take a daily supplement containing 10 micrograms of vitamin D.
Further reading & references
- Management of osteoporosis; Scottish Intercollegiate Guidelines Network - SIGN (2004)
- Guidelines for Osteoporosis in Inflammatory Bowel Disease and Coeliac Disease; British Society of Gastroenterology (2007)
- Guideline for the diagnosis and management of osteoporosis in postmenopausal women and men from the age of 50 years in the UK; National Osteoporosis Guideline Group (updated 2014)
- Alendronate, etidronate, risedronate, raloxifene and strontium ranelate for the primary prevention of osteoporotic fragility fractures in postmenopausal women (amended); NICE Technology Appraisal Guidance, January 2011
- WHO Scientific Group on the Assessment of Osteoporosis at Primary Health Care Level; World Health Organization, 2004
- Stransky M, Rysava L; Nutrition as prevention and treatment of osteoporosis. Physiol Res. 2009;58 Suppl 1:S7-S11.
- Management of osteoporosis in a post-menopausal woman; MeReC Bulletin Vol 20, No 01, 2010
Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. EMIS has used all reasonable care in compiling the information but makes no warranty as to its accuracy. Consult a doctor or other healthcare professional for diagnosis and treatment of medical conditions. For details see our conditions.
Dr Hayley Willacy