It is used by every cell and keeps bones and teeth strong; that is why you need a constant supply throughout your life, writes DR BRIGID MONDA

Calcium is the most abundant mineral in your body. Ninety nine per cent of it is in the bones and teeth, one per cent in blood, muscles, and other soft tissues. Calcium is used by every cell in the body keeping bones and teeth strong, maintaining normal nerve and muscle function, regulating the heart’s rhythm and for blood clotting.

The body gets the calcium it needs in two ways. Through foods such as milk or by ‘borrowing it’ from the bones. Bones are your calcium bank. The mineral is ‘deposited’ in and ‘withdrawn’ from this bone bank depending on your needs.

If you are a healthy adult, you lose 500 milligrams of calcium from your bones every day to maintain a precise level in the blood at all times. At that rate, it would not take long for your bones to become powder if you did not replace this calcium every day. That is why you need a constant supply of calcium throughout your life.

The amount you need depends on your age. You need a lot of calcium during your growing years to build strong bones, a little less in the middle years to keep your bones strong and much more later in life to prevent bone loss.

The recommended amount of calcium for women ages 19 to 50 years, pregnant or not, is a 1,000mg per day; for teenage girls up to age 18, it is 1,300 mg daily. Post-menopausal women need up to 1,500 mg per day.

Sunshine vitamin

For bone health, vitamin D is also important because it is used to transport calcium to your bones. When blood levels of calcium drop, vitamin D travels to the intestines to encourage more calcium absorption into the blood and also to the kidneys to minimise calcium loss in the urine.

Vitamin D is called the ‘sunshine vitamin’ because your body can make its own in your skin from the sun. Milk and eggs also contain vitamin D.

For fair-skinned individuals, 15 minutes of sunlight will produce enough vitamin D to last for several days. It takes a little longer for this to happen with dark-skinned people. Vitamin D is also present in fish, fortified milk and cereals.

So when do you need to take calcium supplements?

Though a common habit in women over 40, food is the best source of calcium because it provides other important nutrients. Three glasses of milk provide about 900 mg of elemental calcium. Elemental calcium is the actual amount of calcium available to your body.

Osteoporosis

When your dietary calcium intake is too low, your body will ‘withdraw’ the calcium it needs from your bones.

Over time, if more calcium is taken out of your bones than is put in, the result is thin and weak bones and if this continues you develop osteoporosis.

To increase calcium in your diet, add cheese to salads and milk to casseroles and soups. Use skimmed milk and reduced-fat cheese if you’re trying to cut back on fat because skimmed milk actually has a higher content of calcium than full fat milk.

Try and get most of your protein from plants, not animal protein like fish, poultry, red meat, eggs, and dairy products because as your body digests protein, it releases acids into the bloodstream which the body neutralises by drawing calcium from the bones and it is then flushed out in urine.

Plant protein such as beans, grains and vegetable has less of that effect.

Avoid excess salt as well because the sodium in salt greatly increases calcium loss through the kidneys into urine.