Why do we need calcium?
Calcium is the most abundant mineral in the body. Most people know that calcium is important for bone and teeth health, but it also helps with nerve signalling, blood clotting and regulating muscle contractions (including the heart).
Where do we get it from?
Good sources of calcium include dairy products, soy beans, green leafy vegetables (broccoli, kale and cabbage) and nuts. Any fish where you eat the bones (eg. sardines or white bait) will also contribute calcium to the diet.
Fortified flour is often used to make bread and other products, so although this is not a rich source, some of our calcium comes from these products as they are consumed so regularly. Some brands of tofu and breakfast cereal are fortified with calcium too (check the label).
How much do we need?
Calcium requirements change for different ages. This is because of needs associated with bone growth. Below shows calcium reference nutrient intakes for different ages (Department of Health, 1991).
0-12 months: 525mg
1-3 years: 350mg
4-6 years: 450mg
7-10 years: 550mg
11-18 years: 1000mg (male) and 800mg (female)
19+ years: 700mg
A 200ml glass of cows milk will provide you with 250mg of calcium and a pot of yoghurt contains about 150mg. Vegan sources are not as rich, with 100g of broccoli providing around 40mg of calcium.
What if we don’t get enough?
Not having enough calcium over a long period of time could lead to osteoporosis and increased risk of bone fractures in later life. It can also cause development of rickets in children. See my post on vitamin D for more information on rickets.
What if we get too much?
Too much calcium usually occurs through use of a supplement but can lead to stomach pain and bowel disturbances. Intakes of less than 1500mg are unlikely to cause any problems.
Department of Health (1991). Dietary reference values for food energy and nutrients for the United Kingdom.