It helps muscles work and nerves carry messages between the brain and other parts of the body too.
How Much Should You Take?
It depends on how much you are already getting in your diet. Adults need 1,000 milligrams of calcium (from all sources) every day, and that amount goes up with age.
Women over 50 and men over 70 need 1,200 milligrams per day. If you think you need a supplement to boost your number, check with your doctor.
The more calcium you take at one time, the harder it is for your body to process it. Aim for 500 milligrams or less.
You may want to take a smaller amount at each meal throughout the day to add up to your total.
More than the recommended daily amount is not good for you. It may even be harmful, according to a 2011 study in the Journal of Clinical Endocrinology and Metabolism.
Your body gets rid of extra calcium through your kidneys, and it goes into your urine, raising the risk of kidney stones for some people.
High levels of the mineral in your blood can lead to kidney problems, as well as hardened blood vessels and tissue.
Some studies also link high calcium intake, particularly from supplements, with a greater risk of heart disease, though the results are not settled.
Calcium Carbonate or Calcium Citrate?
Calcium carbonate is the more common of the two main types of calcium supplements. You should also eat something when you take it to help your body use it best. It does not matter if you take calcium citrate with or without food.
A supplement may have more calcium carbonate as an ingredient than one with calcium citrate, but they could be equally effective.
When you compare products, check the labels to find out how much actual calcium you'll be getting in a dose.
Side Effects and Interactions
Gas, bloating, and constipation is more common with calcium carbonate. That is another reason to share your dose up into servings and to take them with food. Drinking more fluids may help you avoid these symptoms, too.
Trying a new type of calcium supplement? Start with a small dose, like 200-300 milligrams daily for a week, and build up gradually.
Calcium can make certain drugs less effective, so talk to your doctor if you're taking a prescription medicine for osteoporosis or Paget's disease, seizures, or thyroid problems, or an antibiotic.
Some antacids, laxatives, and steroids can pull calcium out of your body or keep you from using it well.
The Vitamin D Connection
Your body needs vitamin D in order to take in and use calcium. And if you're like almost 3/4 of Americans, you aren't getting the recommended amount: 400-800 international units daily for adults under 50, and 800-1,000 if you're older. So, many calcium supplements also include vitamin D.