Calcium for strong bones

bell peppers

and a strong body

Calcium is an essential mineral that plays an important role in nerve conduction, muscle contraction, and blood clotting. Calcium is also needed to build and maintain strong bones and helps reduce the risk of osteoporosis. Of all the calcium in the body, 99 percent is found in our bones and teeth.

How much calcium do I need?

Daily Dietary Reference Intakes for calcium are: 

  • children 1 to 3 years old: 700 mg
  • children 4 to 8 years old: 1,000 mg 
  • children and teenagers 9 to 18 years old (including girls who are pregnant or breastfeeding): 1,300 mg 
  • adults 19 to 50 years old (including women who are pregnant or breastfeeding): 1,000 mg 
  • adults 51 to 70 years old: 1,200 mg for women and 1,000 mg for men
  • adults 71 years old and older: 1,200 mg

For best absorption, calcium supplements should be taken with food and should not exceed 500 mg at a time.

How much is too much?

Too much calcium can cause constipation, increase your risk for developing calcium kidney stones, and may block the absorption of iron and zinc from foods. Too much calcium from supplements has also been associated with increased risk of cardiovascular disease.

Good sources of calcium

The best way to meet your calcium needs is through the foods you eat. Dairy products are an excellent source. One cup of nonfat milk contains 300mg of calcium — a quarter of your daily recommended intake. Choose low- or nonfat dairy products to cut down on calories and fat without losing calcium. You can find lactose-free dairy goods at most grocery stores.

Nondairy calcium-rich foods like green vegetables or fortified foods such as cereals, orange juice, and unsweetened soy and almond milk can also supply your calcium needs. Many of these foods are also fortified with vitamin D to help with calcium's absorption.

Vitamin D

Vitamin D helps absorb calcium and also helps our bodies turn calcium into bone. Adults 70 and older need 800 IU of vitamin D (preferably vitamin D3) daily. Adults under the age of 70 should aim for 600 IU of vitamin D a day. Your doctor may recommend a higher amount of vitamin D if you are deficient. Vitamin D is often combined with calcium in some supplements — be sure to check the label.

Reviewed by: Carole Bartolotto, MA, RD, April 2016
Additional Kaiser Permanente reviewers

© 2016 Kaiser Permanente

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