Calcium is an essential mineral that the body needs for numerous vital functions. Ninety-nine percent of the calcium in the body is stored in the bones and teeth, providing support for both structure and function. The remaining 1% is required for blood clotting, nerve transmission, regulation of the heart’s rhythm and other critical metabolic functions. Since the body cannot produce calcium, it must be absorbed from food and supplements.
The recommended intake of calcium varies by individual. The Food and Nutrition Board at the Institute of Medicine of the National Academies recommends the following calcium intakes:
Adequate calcium can be acquired from a healthy diet. Calcium enriched food include:
Although milk is good source of calcium, milk proteins increase the acidity of the body, which actually leaches calcium from bones.
Dairy products including yogurt and hard cheese such as cheddar, Swiss, and Parmesan are acceptable sources of calcium, but should be eaten in small amounts compared to other sources.
There are several different types of calcium supplements on the market. They contain different calcium compounds and it is important to know how they are different. Below are the three most popular calcium supplement types:
Calcium carbonate is the most common calcium compound in calcium supplements on the market today. Its popularity is due to it being the cheapest form. Calcium carbonate is simply chalk; it has poor bioavailability and cannot be digested without acid. It must be taken with food to be absorbed by your body and it is not recommended for people who have gastrointestinal issues.
Coral calcium is calcium carbonate with trace minerals that are derived from coral reef. Coral calcium is NOT recommended as it has a high risk of heavy metal (lead and mercury) contamination from the sea. Also, it is not an environmentally friendly option since the coral from which it is sourced takes millennia to grow.
Calcium citrate and/or malate are the most absorbable and tolerated form. Clinical studies found that calcium citrate shows a 27.2% increase in absorption on an empty stomach and a 21.6% increase with meals, when compared to calcium carbonate. In addition, Calcium citrate is the one calcium compound that does not require acid in order to be broken down.
Potential side effects: Calcium supplements are prone to cause constipation in some individuals.