The mineral calcium helps your muscles, nerves, and cells work normally.
Your body also needs calcium (as well as phosphorus) to make healthy bones. Bones are the main storage site of calcium in the body.
Your body cannot make calcium. The body only gets the calcium it needs through the food you eat, or from supplements. If you do not get enough calcium in your diet, or if your body does not absorb enough calcium, your bones can get weak or will not grow properly.
Bone density refers to how much calcium and other minerals are present in a section of your bone. Bone density is highest between ages 25 and 35. It goes down as you get older. This can result in brittle, fragile bones that can break easily, even without a fall or other injury.
As you age, your body still needs calcium to keep your bones dense and strong. Most experts recommend at least 1,200 milligrams of calcium and 800 to 1,000 international units of vitamin D a day. Your doctor may recommend a supplement to give you the calcium and vitamin D you need.
Some groups recommend much higher doses of vitamin D, but many experts feel that high doses of vitamin D are not safe for everyone. Be sure to discuss with your health care provider whether supplements are a good choice for you.
Follow a diet that provides the proper amount of calcium, vitamin D, and protein. These nutrients will not completely stop bone loss, but they will help ensure that your body has the materials it needs to build bones.
Leafy green vegetables, such as spinach and collard greens
Sardines (with the bones)
Lorenzo JA, Canalis E, Raisz LG. Metabolic bone disease. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, eds. Williams Textbook of Endocrinology. 12th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 29.
Moyer VA. U.S. Preventive Services Task Force. Vitamin D and calcium supplementation to prevent fractures in adults: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med. 2013;158:691-6.
The National Osteoporosis Foundation (NOF) Clinician's Guide to prevention and treatment of osteoporosis. National Osteoporosis Foundation, Washington, DC. 2013.
Brent Wisse, MD, Associate Professor of Medicine, Division of Metabolism, Endocrinology & Nutrition, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.