Calcium

Calcium is the most abundant mineral in the body and nearly all of it (99%) is in the bones, teeth, soft tissues and blood. It accounts for about 2% of body weight.

Calcium is an essential nutrient for strong bones and healthy teeth but is equally vital as a regulator in most of our body tissues, helping nerves and muscles to work properly.

All calcium required for bones and teeth comes from our diet. Milk and milk products are the major source in the British diet. White and brown bread (by law fortified with calcium), cereal products, vegetables and hard water also provide significant amounts.

How much calcium do we need?

We should ensure we have an adequate intake of calcium

throughout our life. Calcium is a vital mineral which helps our bodies function, as well as being a 'bone builder' in the early years of our lives.
Peak bone mass is reached at the age of about 30-35 years. It is the stage at which bone is strongest. After this age bone mass gradually decreases. Achieving a good peak bone mass is important in reducing the risk of osteoporosis in later life because it means that bones are strong before loss begins.

The Recommended Daily Allowance (RDA) for calcium is 800 mg. but older people may require more.

Surveys show that adults generally take in satisfactory levels of calcium but the intakes of 16-24 year olds are significantly lower than those of people aged over 35.

A survey of British schoolchildren aged 10-15 showed that the intakes of both boys and girls (intakes for boys were greater) were considerably lower than recommended (National Diet & Nutrition Survey). In particular the intakes of some girls who consumed very little milk or cereal products were less than 300 mg per day. This is a cause for concern. Young people whose intake is regularly as low as 300 mg per day are not getting sufficient calcium at a crucial age for the development of bones and teeth.

Consumption of vegetables in the UK is relatively low and accounts for less than 15% of calcium intake. Vegans, who do not consume milk or milk products and who often prefer wholemeal bread, have lower calcium intakes; consume an average of 537 mg calcium per day mainly from vegetable sources. Calcium from wholemeal bread and some vegetable sources is not as easily absorbed by the body.

Bread

By law white and brown flours are fortified with calcium so that white or brown breads are preferable to wholemeal for people whose calcium intake may be inadequate.

Osteoporosis

Osteoporosis is a condition in which the density of bones is reduced. This is due to a loss of both protein and calcium from the bone. Because of the osteoporosis the bones are weaker and break more easily.

 
Osteoporosis occurs usually as a result of the ageing process, in both men and women, and in the years following menopause for women as a result of oestrogen deficiency.

Calcium deficiency has been implicated in the development of osteoporosis through failure to achieve an adequate peak bone mass during early years (usually by the age of 30-35), or an increased rate of bone loss in later life. There does not appear to be any relationship between current calcium intake and present bone mass.

Bone loss following the menopause cannot be prevented by extra calcium alone. However, calcium supplements may reduce the dose of oestrogen necessary to prevent bone loss. Regular weight bearing exercise, such as brisk walking or dancing, reduces the risk of osteoporosis.