Ten million Americans suffer from osteoporosis, and 34 million are at risk for developing it, according to the National Osteoporosis Foundation. Osteoporosis is a condition characterized by porous bones that have lost density and become weak. Calcium builds strong bones and keeps them healthy. The body does not produce calcium; therefore, you must get it from the foods you eat. If you do not consume enough dietary or supplemental calcium, your body will pull calcium from your bones to meet its needs. The National Institutes of Health notes that food is the best form of calcium, meaning it is most easily absorbed. However, most Americans do not consume enough to meet their needs. The two common forms of supplemental calcium are calcium carbonate and calcium citrate.
The majority of your bone mass is built during infancy through adolescence. Bone loss begins in adulthood and gradually increases, significantly increasing in menopausal women. Therefore, you need continued intake of calcium to replace what is being lost. The Recommended Dietary Allowance for calcium provides a guideline for the recommended intake. Children 1 to 3 years old need 700 mg, 4 to 9 years old 1,000 mg, and 9 to 18 years old 1,300 mg of calcium per day. Adults 19 to 50 years old require 1,000 mg, and adults 51 years and over need 1,200 mg of calcium.
Sources of Calcium
Diet is the best way to meet your calcium requirements. The most efficient source of dietary calcium comes from dairy foods such as milk, yogurt and cheese. Other sources include collard greens, kale, spinach and broccoli. Some foods, including juice, tofu and cereal, are also fortified with calcium. When you cannot meet your calcium requirements through diet, you can take calcium supplements.
Calcium carbonate and calcium citrate are available over the counter. The label indicates the amount of elemental calcium in each dose and how much you need to take. Doses of calcium less than 500 mg at a time are better absorbed. It is best to take calcium carbonate with food. Calcium citrate is more easily absorbed than calcium carbonate and may cause fewer side effects such as gas, constipation and bloating, especially in someone with reduced stomach acid. Chewable and liquid forms of calcium supplements are already broken down before entering your stomach, making them easier for your body to absorb.
Although you need vitamin D to absorb calcium, you do not need to combine it with the calcium source or take it at the same time as the calcium. The most common sources of vitamin D are fortified milk and sun exposure.
- National Osteoporosis Foundation; Why Bone Health Is Important
- "Medical Nutrition & Disease, A Case-based Approach"; Lisa Hark, Ph.D., RD, Gail Morrison, MD, eds.; 2003
- NIH Office of Dietary Supplements: Calcium