Calcium

Our bodies need calcium more than any other mineral to ensure bone and muscle health. What is a nutrient? Nutrients are substances we must eat for good health. alive features an important nutrient each month.

Health Claims

Calcium is used for preventing osteoporosis and treating leg cramps, high blood pressure, PMS, insomnia and restless legs syndrome.

What is It?

Calcium is an important mineral required by many body functions. In fact, of all minerals, we need to consume the most calcium by eating calcium-rich foods and/or taking supplements.

How Does it Work?

Ninety-nine per cent of our calcium is stored in bones and teeth. Calcium is also involved in muscle contraction and relaxation in skeletal muscle, smooth muscle in the intestines and uterus, and in heart muscle. Without sufficient calcium, cardiac muscle can spasm, which can lead to cardiac failure. Lack of calcium can also contribute to muscle or menstrual cramps.

Calcium is important in every cell membrane, where it is involved in transport of nutrients. This mineral also functions in the breakdown of acetylcholine, the substance necessary for transmitting nerve impulses. This may explain the effects of calcium on anxiety and insomnia.

What Evidence Supports its Use?

Much research and clinical experience has proven calcium's beneficial effect. In one Scandinavian trial, 20 of 21 women experienced reduction in leg cramp symptoms. For more than 1,000 years, calcium has been used in traditional Chinese medicine for palpitations with anxiety, restlessness and insomnia. Many patients find taking 1,000 milligrams of calcium, especially in liquid form, before bed is very relaxing.

Calcium has been shown to lower blood pressure and reduce symptoms of premenstrual syndrome. Supplement-ation during pregnancy in populations with low calcium intake appears effective in helping prevent pre-eclampsia (toxemia of pregnancy).

How Should I Take It?

The best dietary sources of calcium are cheese (860 mg/3 oz), turnip greens (492 mg/cup), sardines (372 mg/3 oz) and yogurt (345 mg/cup). As for supplements, my patients always want to know the correct daily dose, which depends somewhat on age and activity level. The general recommended dietary allowance for adults is 800 mg. Additional calcium (1,200 mg) has been recommended for pregnant and lactating women. For osteoporosis, a 1,500 mg dose is typical.

Most naturopathic doctors recommend calcium citrate because of its solubility and absorbability. Calcium carbonate, found in oyster shells, can have reduced absorption in elderly individuals who do not secrete enough stomach hydrochloric acid.

Vitamin D increases absorption of calcium. You can eat all the calcium you want, but it will not be absorbed without vitamin D. Canadians have been found to be vitamin D deficient, suggesting this could be a contributing cause of rising osteoporosis rates.

Calcium is more soluble in high-pH stomach acid. As we age, hypochlorhydria (low stomach acid) is common. Some estimates suggest 30 percent of the population over age 60 produces no hydrochloric acid; all of these people are at risk for osteoporosis. For these people and others low in stomach acid, the ionized forms of calcium, such as chelate and citrate, tend to be more soluble and have a greater absorption rate.

The Bottom Line

To ensure you're getting enough calcium, eat calcium-rich foods and take 500 to 1,000 mg of calcium every day along with 800 IU of vitamin D3. Sardines are among the best dietary sources of calcium, at 372 mg/3 oz.