Of the body's calcium, 99% is stored in
your skeleton where it is critical in bone formation. The remaining 1%
if found in various body membranes, soft tissues and body fluids.
Besides its role in bone-formation, calcium is also involved in blood
clotting, nerve transmission, muscle contraction and enzyme activity.
Osteoporosis is the term generally used to
describe drastic loss of calcium from bones which is often seen in
post-menopausal women. The condition leads to lower bone density and to
brittle bones. The term osteopenia better describes the condition found
in some athletes. With this, there is a reduced bone mass which may be a
result of inadequate bone formation during growth or loss of bone mass
due to low oestrogen levels.
Who Is At Risk ?
Some women, particularly endurance
athletes, ballet dancers or gymnasts, may experience delayed menarche or
other menstrual irregularities (called sports amenorrhoea). These
athletes usually have a low percentage of body fat, exercise rigorously
and have low oestrogen levels. Having low oestrogen levels will
accelerate bone loss and, as a result, lead to a decrease in bone
Other risk categories include athletes with
eating disorders, veteran athletes and post-menopausal women.
How Do I Know IF I Have Osteopenia ?
Often than being susceptible to bone
fractures, the only way to find out whether or not you have osteopenia
is by having a bone ultrasound.
How Can I Protect Myself ?
Today we know that the combination of
weight-bearing exercises (such as walking or jogging) and sufficient
calcium in your diet, as well as adequate oestrogen levels help to
protect you from osteopenia. If you belong to any of the above groups,
you will need 1,000-1,500 mg of calcium daily. This means drinking
plenty of low-fat milk, and eating plenty of low-fat cheese, yoghurt and
other dairy products.
Best Sources of Calcium
The richest, and most easily absorbed
source of dietary calcium are dairy products. Canned fish with bones,
fortified soy beverages, nuts, seeds and leafy green vegetables are also
good calcium sources. For the greatest overall benefit, keep these two
points in mind:
- Diets too high in salt, protein,
caffeine, phosphorus or fiber will inhibit your body's ability to absorb
calcium from your food.
- Full-cream dairy products are also high
in fats. Make sure you use skimmed, low-fat or reduced-fat dairy
If you eat a well-balanced diet, you should
receive enough calcium.