Diet - calcium

Alternative names

Calcium in diet

Definition

Calcium is the most plentiful mineral found in the human body, accounting for 1.5% to 2% of an adult's total body weight. The teeth and the bones contain the majority of the body's calcium (about 99%). Calcium in these tissues is concentrated in the form of calcium phosphate salts. Nerve cells, body tissues, blood, and other body fluids contain the remaining calcium.

Function

Calcium is one of the most important minerals for the growth, maintenance, and reproduction of the human body. Calcium is essential for the formation of and maintenance of healthy teeth and bones.

The bones incorporate calcium into their structure. Like other tissues in the body, bones are continually being reabsorbed and re-formed. Teeth incorporate calcium in their structure in a manner similar to bones.

Calcium has other functions in addition to maintaining healthy teeth and bones. Blood coagulation, transmission of nerve impulses, muscle contraction and relaxation, normal heartbeat, stimulation of hormone secretion, activation of enzyme reactions, as well as other functions all require small amounts of calcium.

Food Sources

Many foods contain calcium, but dairy products are the most significant source. Milk and dairy products such as yogurt, cheeses, and buttermilk contain an efficiently absorbed form of calcium.

For children between the ages of 1 and 2 years old, whole milk (4%) is recommended. The fat content of dairy products is a concern for adults and children over the age of two. You can easily reduce the fat content of dairy products while maintaining the calcium content by selecting low-fat (2% or 1%) or skim milk.

The calcium is not contained in the "fat portion" of milk, so removing the fat will not affect the calcium content. In fact, when you replace the fat portion that has been removed with an equal part of skimmed milk, you are actually increasing the calcium content. Therefore, one cup of skim or non-fat milk will have more calcium than one cup of whole milk because almost the entire cup of skim milk is the made up of the calcium-containing portion!

Other dairy products such as yogurt, most cheeses, and buttermilk are excellent sources of calcium and are available in low-fat or fat-free versions.

Milk is also a good source of phosphorus and magnesium, which help the body absorb and use the calcium more effectively. Vitamin D is essential for efficient utilization of calcium. Milk is fortified with vitamin D for this reason.

Green leafy vegetables such as broccoli, collards, kale, mustard greens, turnip greens, and bok choy or Chinese cabbage are good sources of calcium. Certain green vegetables are less effective sources of calcium. While their calcium content appears to be high, their fiber and oxalic acid content interferes with the absorption of calcium.