Calcium

Source: MedlinePlus Health Topics, U.S. National Library of Medicine

Last synced 8/9/2026Status: primary verified

What is calcium and why do I need it? Calcium is a mineral , a nutrient that you need (in small amounts) to keep your body healthy. You have more calcium in your body than any other mineral. Calcium has many important jobs: To build and maintain strong bones. Your body stores almost all of its calcium in your bones and teeth to keep them strong. To help your muscles move. To help your nerves to carry messages between your brain and the rest of your body. To help your blood vessels move blood throughout your body. To help release hormones that affect many functions in your body. Not getting enough calcium can cause several conditions, including: Osteoporosis , a disease which can make your bones weaker and more likely to break. Rickets , a disease in children that causes soft, weak bones. Osteomalacia, a condition which causes soft bones in children and adults. How do I get calcium? You can get calcium from foods and supplements. You may be able to get enough calcium by eating a variety of foods, including: Dairy products such as milk, cheese, and yogurt. These are the main food sources of calcium for most people in the United States. Leafy, green vegetables such as kale, broccoli, and Chinese cabbage (bok choi). Fish with soft bones that you can eat, such as canned sardines and salmon. Calcium-enriched foods such as breakfast cereals, fruit juices, soy and rice drinks, and tofu. The product labels for these foods will show how much calcium they have. Calcium is available in supplements. It is also included in many multivitamins. The two main forms of calcium supplements are calcium carbonate and calcium citrate: Calcium carbonate is absorbed best when taken with food. Some over-the-counter antacids, such as Tums and Rolaids, also contain calcium carbonate. Calcium citrate is absorbed well on an empty stomach or a full stomach. People with low levels of stomach acid absorb calcium citrate more easily than calcium carbonate. Calcium is absorbed best when you take 500

Educational only

This information is for general education and is not medical advice. Always talk to a licensed U.S. clinician about your situation, medications, or treatment decisions.