Calcium, vitamin D, and your bones

Also known as: Osteoporosis - calcium and Osteoporosis - low bone density

Bone Strength and Calcium

Your body needs calcium to keep your bones dense and strong. Low bone density can cause your bones to become brittle and fragile. These weak bones can break easily, even without an obvious injury.

Vitamin D helps your body absorb calcium. Eat foods that provide the right amounts of calcium, vitamin D, and protein. This kind of diet will give your body the building blocks it needs to make and maintain strong bones.

How Much Calcium and Vitamin D do I Need?

Amounts of calcium are given in milligrams (mg), and vitamin D is given in international units (IU).

All children ages 9 to 18 should have:

  • 1300 mg of calcium daily
  • 600 IU of vitamin D daily

All adults under age 50 should have:

  • 1000 mg of calcium daily
  • 400 to 800 IU of vitamin D daily

Adults age 51 and older should have:

  • Women: 1200 mg of calcium daily
  • Men: 1000 mg of calcium daily

Men and women: 800 to 1000 IU of vitamin D daily

Too much calcium or vitamin D can lead to problems such as an increased risk for kidney stones.

  • Total calcium should not exceed 2000 mg per day
  • Total vitamin D should not exceed 4000 IU per day

Calcium and Dairy Products

Milk and dairy products are the best sources of calcium. They contain a form of calcium that your body can absorb easily. Choose yogurts, cheeses, and buttermilk.

Adults should choose fat-free (skim) milk or low-fat (2% or 1%) milk, and other lower fat dairy products. Removing some of the fat does not lower the amount of calcium in a dairy product.

  • Yogurt, most cheeses, and buttermilk come in fat-free or low-fat versions.
  • Vitamin D helps your body use calcium, which is why vitamin D is often added to milk.

If you eat very few or no dairy products, you can find calcium in other foods. It is often added to orange juice, soy milk, tofu, ready-to-eat cereals, and breads. Check the labels on these foods for added calcium.

Other Sources of Calcium

Green leafy vegetables, such as broccoli, collards, kale, mustard greens, turnip greens, and bok choy (Chinese cabbage), are good sources of calcium.

Other good food sources of calcium are:

  • Salmon and sardines that are canned with their bones (you can eat these soft bones)
  • Almonds, Brazil nuts, sunflower seeds, tahini (sesame paste), and dried beans
  • Blackstrap molasses

Other tips to make sure your body can use the calcium in your diet:

  • Cook high-calcium vegetables in a small amount of water for the shortest possible time. They will retain more calcium this way.
  • Be careful about what you eat with calcium-rich foods. Certain fibers, such as wheat brain and foods with oxalic acid (spinach and rhubarb), can prevent your body from absorbing calcium.

Your doctor may recommend a calcium or vitamin D supplement for the calcium and vitamin D you need. However, the balance between benefits and harms of these supplements is unclear.


Cosman F, de Beur SJ, LeBoff MS, et al. Clinician's Guide to Prevention and Treatment of Osteoporosis. Osteoporos Int. 2014;25(10):2359-2381. PMID: 25182228

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(9):691-696. PMID: 23440163

National Institutes of Health, Office of Dietary Supplements. Dietary supplement fact sheet: Calcium. Updated June 01, 2016. Accessed July 19, 2016.

National Osteoporosis Foundation. Vitamin D and bone health. Osteoporosis Clinical Updates 2012. Accessed July 19, 2016.

Review date:
December 07, 2016
Reviewed by:
Gordon A. Starkebaum, MD, Professor of Medicine, Division of Rheumatology, 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.
Copyright Information A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission ( URAC's accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial policy, editorial process and privacy policy. A.D.A.M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health on the Net Foundation (

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- 2008 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.