Calcium is a metal element with the chemical symbol Ca. The calcium in foods and supplements is in a compound form. This means that besides calcium, other elements form the molecule. Most commonly, calcium is combined with carbonate or citrate. The calcium in the compound is referred as elemental calcium. When you digest the compound, it dissolves and the elemental calcium is released and becomes available for absorption.
Calcium Carbonate
The calcium found in oyster shells is calcium carbonate. Calcium carbonate is the most common type of calcium used in supplements, according to the University of Arizona College of Agriculture and Life Sciences. Oyster shells are used as a natural source of calcium for supplements. Calcium carbonate has 40 percent elemental calcium and 60 percent of carbonate. This means that when you take a 500 mg of calcium carbonate, it only has 200 mg of elemental calcium. The digestion of calcium carbonate requires higher levels of stomach acid and thus, the supplement should be taken with meals.
Other Types of Calcium
Calcium citrate is the most readily absorbed form of calcium supplement and does not require an acidic environment to dissolve. Calcium citrate also comes as a liquid form that may be more gentle for your stomach. There is only 21 percent of elemental calcium in calcium citrate supplements. Other types of calcium supplements on the market are calcium phosphate, lactate and gluconate. However, these supplements contain only small percentages of elemental calcium and you need to consume several tablets to get the recommended daily dosage of calcium.
Why Do You Need Calcium
According to the U.S. National Library of Medicine and National Institutes of Health, calcium is necessary for healthy teeth and bones, and also plays important roles in muscle contraction, nerve conduction and blood-clotting. If your blood calcium levels drop below normal, your body responds by taking calcium from your bones. Common disorders caused by calcium deficiency are osteoporosis, rickets and osteomalacia. Calcium supplements may also reduce the risk of colorectal cancer, high blood pressure, pre-eclampsia, stroke in women and may help reduce body weight and fat while dieting.
Daily Recommendations
The amount of calcium you should get on daily basis differs between different age groups. According to the University of Arizona, recommended amounts are 200 to 260 mg per day for infants, 700 to 1,000 mg for children, 1,300 mg for adolescents, 1,000 mg for adults, and 1,200 mg for women 51 years and older. You should limit your calcium intake to 2,500 mg per day. Higher doses may cause serious health conditions, including heart attack, according to the U.S. National Library of Medicine and National Institutes of Health. Great dietary sources for calcium are dairy products, dark, green leafy vegetables and fortified juices.
Member Comments