Calcium is a mineral important for strong bones and teeth. Too little calcium can lead to the bone conditions rickets and osteoporosis.
Calcium also has a role in blood clotting and the regulation of muscle contractions including the heartbeat.
There is some evidence calcium has a role in managing blood pressure and preventing breast and colon cancer.
Most people should get enough calcium from a balanced healthy diet, but calcium supplements may be recommended for some people.
Use of calcium
Calcium is commonly found in antacids used to treat indigestion. Doctors also use calcium to control high levels of magnesium, phosphorus and potassium in the blood. It’s possible but not proven that calcium may play a role in preventing certain cancers. It’s also possible but not proven that calcium with vitamin D may help protect against breast cancer in pre-menopausal women, but the data are still inconclusive for post-menopausal women, and the exact relationship regarding vitamin D and calcium intake is still not known. In fact, some research suggests regularly taking calcium supplements may be associated with a greater risk of heart attacks. However, more research is needed and experts say it is not possible to say that calcium supplements actually cause heart attacks, only that there was an increased risk.
While calcium has been looked at for other uses - such as helping with weight loss - these studies have been inconclusive.
People at risk of calcium deficiency include post- menopausal women, those who follow restrictive diets, and since dairy products are one of the most common sources of calcium, people who are lactose intolerant or who follow a vegan diet.
Calcium dose and instructions for use
The Department of Health has set a reference nutrient intake (RNI) for calcium. Getting this amount from your diet, with or without supplements, may be enough to keep your bones healthy. Your doctor may recommend higher doses, depending on your needs.
Calcium:Reference Nutrient Intake (RNI)
|0-12 months||525 mg/day|
|1-3 years||350 mg/day|
|4-6 years||450 mg/day|
|7-10 years||550 mg/day|
|11-18 years (females)||800 mg/day|
|11-18 years (males)||1,000 mg/day|
Women who are pregnant do not require more calcium, but those who are breastfeeding are recommended to have 1,250mg/day.
Taking too much calcium in high doses over 1500mg a day may cause stomach pain and diarrhoea.
Calcium food sources
Good food sources of calcium include:
Experts say that many adults in the UK don't get enough calcium. While improving one's diet will help, many people do need to take calcium supplements as well.