Calcium is important for preventing osteoporosis and bone disease, as it's a major building-block of our bone tissue - our skeleton houses 99 % of our body's calcium stores. The calcium in our bones also acts as a reservoir for maintaining calcium levels in the blood, which is essential for healthy nerves and muscles.
The amount of calcium we need to consume changes at different stages in our lives. Calcium requirements are high in our teenage years with the rapid growth of the skeleton1. With age, the body’s ability to absorb calcium declines, which is one of the reasons why seniors also require higher amounts2.
Calcium rich foods
Milk and dairy products are the most readily available dietary sources of calcium. Dairy foods have the additional advantage of being good sources of protein and other micronutrients important for bone health.
Other sources of calcium include:
- Green vegetables like broccoli, curly kale, and bok choy
- Some fruits such as oranges, apricots and dried figs
- Canned fish with soft, edible bones (the calcium is in the bones) such as sardines, pilchards and salmon
- Nuts, especially Brazil nuts and almonds
Some calcium-fortified breads, cereals, fruit juices, soy beverages and several brands of commercial mineral water also contain significant amounts of calcium. These foods provide a suitable alternative for people who are lactose-intolerant or vegan3.
Some leafy produce, like spinach and rhubarb, contain 'oxalates', which prevent the calcium present in these vegetables from being absorbed. However, they do not interfere with calcium absorption from other calcium-containing foods eaten at the same time. The same is true of 'phytates' in dried beans, cereal husks and seeds.
Foods to avoid
Caffeine and salt can increase calcium loss from the body and should not be taken in excessive amounts. Alcohol should also be taken in moderation as it detracts from bone health and is associated with falls and fractures.
No conclusive evidence shows that fizzy soft drinks (e.g. cola drinks) weaken bones, here too, it's best not to overdo it - especially as such drinks tend to 'displace' milk in the diets of children and teenagers.
Recommended daily calcium intakes
Recommended daily calcium intakes for populations vary between countries. The FAO/WHO (2002) recommendations, based on data from several countries, are as follows:
|Infants and Children||Calcium (mg/day)|
|19 years to menopause||1000|
|During pregnancy (last trimester)||1200|
The 'recommended allowance' refers to the amount of calcium each age group is advised to consume (with daily intake corresponding to an average intake over a period of time), to ensure calcium consumed compensates for calcium excreted from the body each day. The calcium allowance figures for children and adolescents also take account of skeletal growth (net calcium gain), and those for postmenopausal women and the elderly also take account of a lower intestinal calcium absorption efficiency.
Figures based on Western European, American and Canadian data. Source: FAO/WHO: Human Vitamin and Mineral Requirements, 2002.
Are you getting enough calcium? Find out whether you are getting enough of this imporant mineral in your daily diet, using the IOF Calcium Calculator.
1. Specker B and Binkley T (2003) Randomized trial of physical activity and calcium supplementation on bone mineral content in 3- to 5-year-old children. J Bone Miner Res 18:885
2. Chapuy MC, Arlot ME, Duboeuf F, et al. (1992) Vitamin D3 and calcium to prevent hip fractures in the elderly women. N Engl J Med 327:1637
3. Obermayer-Pietsch BM, Bonelli CM, Walter DE, et al. (2004) Genetic predisposition for adult lactose intolerance and relation to diet, bone density, and bone fractures. J Bone Miner Res 19:42
- What is Osteoporosis?
- Who's at Risk?
- Living with Osteoporosis