CALCIUM

The Role of Calcium

Calcium is an essential mineral that is found predominantly in the teeth and bones (99%) but is also found in nerve cells, body tissues, blood, and other body fluids (1%). While we know calcium is important for bone health, calcium is also involved in processes beyond bone formation. Without calcium, hormone secretion, blood clotting, muscle contraction, and the transmission of nerve signals could not occur. Clearly, calcium is vital for the livelihood of our bodies. When calcium is not immediately available in the blood, the brain tells the body to take calcium from the bones. Since bones are constantly being "broken down" as a result of this process, it is important to provide the body with enough calcium daily so that the bones can "build themselves back up". Without enough dietary calcium, the bones will become porous and brittle over time, potentially leading to osteoporosis. Calcium deficiency has also been associated with high blood pressurre and oral health problems. Supplementing with calcium daily can help ensure that the body's needs for this mineral are being met.

Calcium Requirements

The jury is still out on how much calcium is required for optimal bone health. Experts argue between daily intake ranges of 1000-1500 mg per day for adults and puberty-age adolescents. Preschoolers need between 500-800 mg per day and shool-age children need about 800 mg. Teens of both sexes, pregnant, lactating and postmenstrual women have greater requirements for calcium. Including calcium-rich foods in the diet will help ensure adequate intake. See the Food Sources chart for a list of calcium-rich foods.

For those who do not eat enough calcium-rich foods, supplements are also available, but choosing from the variety of supplements can be confusing. Carbonate, Citrate, Chelate - which is the best form for you?

Insoluble Calcium

Insoluble calcium in the form of calcium carbonate must first be ionized and made soluble by stomach acid. If this process is successful, more elemental calcium is available to the body when compared to other forms of calcium, making this supplement a more economical choice. The key to benefiting from this calcium, however, is producing enough stomach acid. Persons with achorhydria (no stomach acid), who are post menopausal, or who do not take their supplements with food, cannot receive much benefit from calcium carbonate. Chronic antacid users will als have difficulty absorbing supplements in this form. In addition, those who suffer from calcium oxalate kidney stones are advised to not supplement with calcium carbonate, opting instead for the citrate form.

Soluble Forms of Calcium:

Soluble forms of calcium include calcium citrate, gluconate, chelate, and lactate. Soluble forms of calcium have a smaller percentage of elemental calcium when compared to calcium carbonate, which requires a greater amount of elemental calcium found in calcium carbonate. However, some experts argue that these forms of calcium allow for easier absorption and better utilization of the mineral. They do not require stomach acid for absorption and have been shown to be more bioavailable than calcium carbonate. Chelation binds the elemental calcium to an acid, which allows for easier recognition and absorption in the intestines. Kreb;s Cycle intermediates are chelating agents (fumarate, malate, succinate, and asparte) that work well in combination with calcium citrate. These forms of calcium are used in the production of energy and are easily ionized. They help with the absorption of calcium and other minerals.

In addition to the form of the calcium, there are other factors to consider. Magnesiium, vitamin D and boron are all nutrients that assist with calcium absorption. Choosing a supplement that contains at least one of these additional nutrients will further enhance calcium utilization. The delivery system is another consideration for supplements - available in tablet, capsule, softgel, liquid or chewables. This comes down to personal preference. The most common form used are tablets and capsules, but teenagers may be more compliant if they can take a tasty calcium softchew, and adults with poor digestion may find liquids easier to take.

Food Sources of Calcium