Types

• The two most efficiently absorbed forms of calcium supplements are calcium carbonate and calcium citrate. The label should say "elemental calcium," which means the amount of calcium that is available for your body to absorb.
  
  

How to Take Supplements

• Calcium carbonate should be taken with food. Calcium citrate can be taken with or without food.
  
  

Significance

• Calcium is important for building strong bones and teeth, but it is also required for muscle contraction, blood-vessel expansion, secretion of hormones and enzymes, and transmission of impulses through the nervous system.
  
  

Time Frame

• According to the National Institutes of Health, we need calcium through food or supplements throughout our life but mostly during the peak years of bone growth, which are between ages 9 and 17. After age 50, men and women will again need more calcium.
  
  

Risk Factors for Deficiency

• Postmenopausal women, amenorrheic women and people who are lactose intolerant are most in need of calcium supplements. Vegetarians who do not eat enough foods containing calcium also risk calcium deficiency.
  
  

Side Effects

• Calcium supplements can sometimes cause gas, bloating or constipation. Taking a lower dose twice a day with meals can help eliminate those symptoms.