Calcium is a mineral that is important for strong bones and a healthy body throughout your life. A healthy diet is the best way to get the calcium you need. But calcium supplements may be an option if you don't get enough from your diet.
Before you think about increasing your calcium intake or taking calcium supplements, be sure you understand how much calcium you need and the benefits and risks of supplements.
The benefits of calcium
Your body needs calcium to build and maintain strong bones. But calcium is not only important for bone health. It also helps the muscles, heart and nerves work as they should.
Some studies suggest that calcium may have benefits for other health conditions. Several studies and health organizations recommend that increased calcium intake may help prevent preeclampsia during pregnancy for those with low calcium levels. Calcium also may help protect against cancer, diabetes, high blood pressure and cholesterol. But more research is needed into these other possible benefits.
The risks of too little calcium
If you don't get enough calcium, you may have issues with bone growth or weakness. Children, adolescents and adults 50 and older are at risk of having low calcium levels.
- Children may not reach their full potential adult height if calcium levels are low.
- Adults are at risk of bone conditions such as osteoporosis or osteomalacia due to low bone mass if they do not get enough calcium. These conditions may cause bones to break more easily or become soft.
Calcium requirements
How much calcium you need depends on your age and sex. Many Americans don't get enough calcium in their diets. These are the daily amounts of calcium recommended for most adults:
- Ages 19 to 50 years: 1,000 mg a day. The total amount of calcium a day should not be more than 2,500 mg.
- Ages 51 and older: 1,000 to 1,200 mg a day. The total amount of calcium a day should not be more than 2,000 mg.
If you are pregnant or breastfeeding, talk with your healthcare professional before you take any supplement.
Calcium and diet
Your body doesn't produce calcium, so you must get it from other sources. Calcium can be found naturally in several different foods. These foods include:
- Milk, yogurt, cheese and other dairy products.
- Leafy green vegetables, such as collard and turnip greens, bok choy, and kale.
- Fish with soft bones you can eat, such as sardines and canned salmon.
Some foods may be calcium fortified, which means calcium has been added. These include:
- Cow's milk and plant-based milks, such as almond, soy and oat.
- Tofu and other soy products.
- Cereals.
- Fruit juices.
Calcium and vitamin D
To absorb calcium, your body also needs vitamin D. Some foods naturally contain small amounts of vitamin D, such as canned salmon with bones, tuna and egg yolks. You also can get vitamin D from foods fortified with the vitamin. The recommended amount of vitamin D for most adults is 600 international units or 15 micrograms a day. Spending time in the sun also helps the body make vitamin D, even when you wear sunscreen.
Do I need a calcium supplement?
Even if you eat a healthy, balanced diet, you may find it difficult to get enough calcium if you:
- Are postmenopausal. When the body produces less estrogen, the bones absorb less calcium. After menopause, more calcium also is lost in urine.
- Follow a vegan diet or have lactose intolerance and limit dairy products.
- Have long-term corticosteroid treatment.
- Have certain bowel or digestive diseases that limit your ability to absorb calcium, such as inflammatory bowel disease or celiac disease.
In these situations, calcium supplements may help you meet your calcium needs. Talk with your healthcare professional about whether calcium supplements are right for you.
Do calcium supplements have risks?
Calcium supplements are not for everyone. For example, if you have a health condition called hypercalcemia that causes calcium to build up in your bloodstream, you should avoid calcium supplements. For some people, supplements may cause constipation.
Some studies suggest that very high calcium levels may increase the risk of kidney issues, prostate cancer and heart disease. But more research is needed. Until more is known about these possible risks, it's important not to take in more than the recommended total limit of calcium in food, drinks and supplements each day. For adults 19 to 50, the total is 2,500 mg a day. For adults 51 and older, the total is 2,000 mg a day. As with any health issue, it's important to talk with your healthcare professional to find out what's right for you.
Types of calcium supplements
Several different kinds of calcium mixtures are used in calcium supplements. Supplement mixtures contain different amounts of elemental calcium. The standard amounts of elemental calcium in these common calcium supplements are:
- Calcium carbonate: 40% elemental calcium.
- Calcium citrate: 21% elemental calcium.
- Calcium gluconate: 9% elemental calcium.
- Calcium lactate: 13% elemental calcium.
Calcium carbonate and calcium citrate are the two most common types of calcium supplements. They have higher amounts of elemental calcium. Calcium gluconate and calcium lactate have lower amounts of calcium and may not do enough to increase calcium levels. But if higher doses of calcium cause issues or discomfort, calcium gluconate and calcium lactate may be an option.
In some supplements, calcium may be combined with vitamins and minerals. For example, vitamin D or magnesium may be added to a calcium supplement. Vitamin D and magnesium help your body better absorb calcium. Check the list of ingredients to see what type of calcium is in the supplement and what other nutrients may have been added. This information is important if you have any health or dietary concerns.
Choosing calcium supplements
When looking at calcium supplements, consider these factors:
- Amount of calcium. The amount of elemental calcium in your supplement is important. Elemental calcium is what your body absorbs for bone growth and other health benefits. The Supplement Facts label on calcium packaging tells how much total calcium is in one serving. For example, calcium carbonate is only 40% elemental calcium, so 1,250 milligrams of calcium carbonate contains 500 milligrams of elemental calcium. That is 40% of 1,250. Also, be sure to check the label to see how many tablets equal a serving.
- Side effects. Calcium supplements cause few, if any, side effects. But some people may have gas, constipation and bloating. You may need to try a few different types or brands of calcium supplements to find what is right for you. Ask your healthcare professional if you should take them with or between meals.
- If you take medicine. Calcium supplements may interact with some medicines. These may include antibiotics, lithium, HIV inhibitors and thyroid hormone treatments. Ask your healthcare professional before taking calcium supplements if you take any medicine.
- Quality. There are several calcium supplements available, and the quality varies. It is up to manufacturers to ensure the supplements they produce are safe and their claims are true. Some companies take the voluntary extra step to have their products tested by outside organizations, such as U.S. Pharmacopeia (USP), ConsumerLab.com (CL) or NSF International. Check the supplement packages for USP, CL or NSF seals, which means the supplements meet industry standards for quality, purity and potency.
- Kind of supplement. Calcium supplements come in different forms, including tablets, capsules, chews, liquids and powders. If you have trouble swallowing pills, you may want a chewable or liquid calcium supplement. All varieties of calcium supplements are better absorbed when taken in small doses of 500 mg or less, typically with a meal.
More isn't always needed or better
If you spend time in the sun, eat a healthy diet that includes foods rich in calcium and have no health conditions, you may be getting enough calcium — or you may not be getting enough. If you take calcium supplements and eat calcium-fortified foods, you may get more calcium than you realize.
Check food and supplement labels to find out how much total calcium you're getting each day and whether you're reaching or going over the recommended daily total. Dietary calcium is generally safe, but there are risks if you take too much, especially in supplement form. Taking more than the recommended daily total doesn't provide extra bone protection.
If you are already taking calcium supplements or thinking about taking them, be sure to talk with your healthcare professional about what is right for you.