Calcium: What Is Needed and Where to Get It
Studies show that many adults don't get enough, which can lead to osteoporosis
Based on content from the NIH publication, “Calcium and Vitamin D: Important at Every Age.”
Calcium is needed for our heart, muscles and nerves to function properly, and for blood to clot.
Inadequate calcium significantly contributes to the development of osteoporosis.
Many published studies show that low calcium intake throughout life is associated with low bone mass and high fracture rates.
Although a balanced diet aids calcium absorption, high levels of protein and sodium (salt) in the diet are thought to increase calcium excretion through the kidneys. Excessive amounts of these substances should be avoided, especially in those with low calcium intake.
Lactose intolerance also can lead to inadequate calcium intake. Those who are lactose intolerant have insufficient amounts of the enzyme lactase, which is needed to break down the lactose found in dairy products.
To include dairy products in the diet, dairy foods can be taken in small quantities or treated with lactase drops, or lactase can be taken as a pill. Some milk products on the market already have been treated with lactase.
If you have trouble getting enough calcium in your diet, you may need to take a calcium supplement. The amount of calcium you will need from a supplement depends on how much calcium you obtain from food sources. There are several different calcium compounds from which to choose, such as calcium carbonate and calcium citrate, among others. Except in people with gastrointestinal disease, all major forms of calcium supplements are absorbed equally well when taken with food.
In many individuals, calcium supplements are better absorbed when taken with food. It is important to check supplement labels to ensure that the product meets U.S. Pharmacopeia (USP) standards.
The body needs vitamin D to absorb calcium. Without enough vitamin D, one can’t form enough of the hormone calcitriol (known as the “active vitamin D”). This in turn leads to insufficient calcium absorption from the diet. In this situation, the body must take calcium from its stores in the skeleton, which weakens existing bone and prevents the formation of strong, new bone.
You can get vitamin D in three ways: through the skin, from the diet, and from supplements. Experts recommend a daily intake of 600 IU (International Units) of vitamin D up to age 70. Men and women over age 70 should increase their uptake to 800 IU daily, which also can be obtained from supplements or vitamin D-rich foods such as egg yolks, saltwater fish, liver and fortified milk. The Institute of Medicine recommends no more than 4,000 IU per day for adults. However, sometimes doctors prescribe higher doses for people who are deficient in vitamin D.
A complete osteoporosis program
Remember, a balanced diet rich in calcium and vitamin D is only one part of an osteoporosis prevention or treatment program. Like exercise, getting enough calcium is a strategy that helps strengthen bones at any age. But these strategies may not be enough to stop bone loss caused by lifestyle, medications, or menopause. Your doctor can determine the need for an osteoporosis medication in addition to diet and exercise.
National nutrition surveys have shown that most people are not getting the calcium they need to grow and maintain healthy bones. To find out how much calcium you need, see the Recommended Calcium Intakes (in milligrams) chart below.
Recommended calcium intakes
Source: Food and Nutrition Board, Institute of Medicine, National Academy of Sciences, 2010.
To learn how easily you can include more calcium in your diet without adding much fat, see the Selected Calcium-Rich Foods list below.
Selected calcium-rich foods
Source: The 2004 Surgeon General’s Report on Bone Health and Osteoporosis: What It Means to You. U.S. Department of Health and Human Services, Office of the Surgeon General, 2004, pages 12–13.
The National Institutes of Health, a part of the U.S. Department of Health and Human Services, is the nation's medical research agency — making important discoveries that improve health and save lives. NIH is the largest single source of financing for medical research in the world, seeking new ways to cure disease, alleviate suffering and prevent illness. By providing the evidence base for health decisions by individuals and their clinicians, NIH is empowering Americans to embrace healthy living through informed decision-making. NIH is made up of 27 institutes and centers, each with a specific research agenda, focusing on stages of life, like aging or child health, or particular diseases or body systems.