Calcium supplements are taken by individuals who are unable to get enough calcium in their regular diet or who have a need for more calcium. They are used to prevent or treat several conditions that may cause hypocalcemia (not enough calcium in the blood). The body needs calcium to make strong bones. Calcium is also needed for the heart, muscles, and nervous system to work properly.
The bones serve as a storage site for the body's calcium. They are continuously giving up calcium to the bloodstream and then replacing it as the body's need for calcium changes from day to day. When there is not enough calcium in the blood to be used by the heart and other organs, your body will take the needed calcium from the bones. When you eat foods rich in calcium, the calcium will be restored to the bones and the balance between your blood and bones will be maintained.
Pregnant women, nursing mothers, children, and adolescents may need more calcium than they normally get from eating calcium-rich foods. Adult women may take calcium supplements to help prevent a bone disease called osteoporosis. Osteoporosis, which causes thin, porous, easily broken bones, may occur in women after menopause, but may sometimes occur in elderly men also. Osteoporosis in women past menopause is thought to be caused by a reduced amount of ovarian estrogen (a female hormone). However, a diet low in calcium for many years, especially in the younger adult years, may add to the risk of developing it. Other bone diseases in children and adults are also treated with calcium supplements.
Calcium supplements may also be used for other conditions as determined by your health care professional.
A calcium "salt" contains calcium along with another substance, such as carbonate or gluconate. Some calcium salts have more calcium (elemental calcium) than others. For example, the amount of calcium in calcium carbonate is greater than that in calcium gluconate. To give you an idea of how different calcium supplements vary in calcium content, the following chart explains how many tablets of each type of supplement will provide 1000 milligrams of elemental calcium. When you look for a calcium supplement, be sure the number of milligrams on the label refers to the amount of elemental calcium, and not to the strength of each tablet.
|Calcium supplement||Strength of each tablet (in milligrams [mg])||Amount of elemental calcium per tablet (in milligrams)||Number of tablets to provide 1000 milligrams of calcium|
|Calcium phosphate, dibasic||500||115||9|
|Calcium phosphate, tribasic||800|
Injectable calcium is administered only by or under the supervision of your health care professional. Other forms of calcium are available without a prescription.
Once a medicine or dietary supplement has been approved for marketing for a certain use, experience may show that it is also useful for other medical problems. Although this use is not included in product labeling, calcium supplements are used in certain patients with the following medical condition:
For good health, it is important that you eat a balanced and varied diet. Follow carefully any diet program your health care professional may recommend. For your specific dietary vitamin and/or mineral needs, ask your health care professional for a list of appropriate foods. If you think that you are not getting enough vitamins and/or minerals in your diet, you may choose to take a dietary supplement.
The daily amount of calcium needed is defined in several different ways.
Normal daily recommended intakes in milligrams (mg) for calcium are generally defined as follows:
|Persons||U.S. (mg)||Canada (mg)|
|Infants birth to 3 years of age||400 to 800||250 to 550|
|Children 4 to 6 years of age||800||600|
|Children 7 to 10 years of age||800||700 to 1100|
|Adolescent and adult males||800 to 1200||800 to 1100|
|Adolescent and adult females||800 to 1200||700 to 1100|
|Pregnant females||1200||1200 to 1500|
|Breast-feeding females||1200||1200 to 1500|
Getting the proper amount of calcium in the diet every day and participating in weight-bearing exercise (walking, dancing, bicycling, aerobics, jogging), especially during the early years of life (up to about 35 years of age) is most important in helping to build and maintain bones as dense as possible to prevent the development of osteoporosis in later life.
The following table includes some calcium-rich foods. The calcium content of these foods can supply the daily RDA or RNI for calcium if the foods are eaten regularly in sufficient amounts.
|Food (amount)||Milligrams (mg) of calcium|
|Nonfat dry milk, reconstituted (1 cup)||375|
|Lowfat, skim, or whole milk (1 cup)||290 to 300|
|Yogurt (1 cup)||275 to 400|
|Sardines with bones (3 ounces)||370|
|Ricotta cheese, part skim (½ cup)||340|
|Salmon, canned, with bones (3 ounces)||285|
|Cheese, Swiss (1 ounce)||272|
|Cheese, cheddar (1 ounce)||204|
|Cheese, American (1 ounce)||174|
|Cottage cheese, lowfat (1 cup)||154|
|Tofu (4 ounces)||154|
|Shrimp (1 cup)||147|
|Ice milk (¾ cup)||132|
Vitamin D helps prevent calcium loss from your bones. It is sometimes called "the sunshine vitamin" because it is made in your skin when you are exposed to sunlight. If you get outside in the sunlight every day for 15 to 30 minutes, you should get all the vitamin D you need. However, in northern locations in winter, the sunlight may be too weak to make vitamin D in the skin. Vitamin D may also be obtained from your diet or from multivitamin preparations. Most milk is fortified with vitamin D.
Do not use bonemeal or dolomite as a source of calcium. The Food and Drug Administration has issued warnings that bonemeal and dolomite could be dangerous because these products may contain lead.
If you are taking a dietary supplement without a prescription, carefully read and follow any precautions on the label. For these supplements, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to medicines in this group or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
Problems in children have not been reported with intake of normal daily recommended amounts. Injectable forms of calcium should not be given to children because of the risk of irritating the injection site.
Problems in older adults have not been reported with intake of normal daily recommended amounts. It is important that older people continue to receive enough calcium in their daily diets. However, some older people may need to take extra calcium or larger doses because they do not absorb calcium as well as younger people. Check with your health care professional if you have any questions about the amount of calcium you should be taking in each day.
It is especially important that you are receiving enough calcium when you become pregnant and that you continue to receive the right amount of calcium throughout your pregnancy. The healthy growth and development of the fetus depend on a steady supply of nutrients from the mother. However, taking large amounts of a dietary supplement during pregnancy may be harmful to the mother and/or fetus and should be avoided.
It is especially important that you receive the right amount of calcium so that your baby will also get the calcium needed to grow properly. However, taking large amounts of a dietary supplement while breast-feeding may be harmful to the mother and/or baby and should be avoided.
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking any of these dietary supplements, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using dietary supplements in this class with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.
Other medical problems
The presence of other medical problems may affect the use of dietary supplements in this class. Make sure you tell your doctor if you have any other medical problems, especially:
Drink a full glass (8 ounces) of water or juice when taking a calcium supplement. However, if you are taking calcium carbonate as a phosphate binder in kidney dialysis, it is not necessary to drink a glass of water.
This dietary supplement is best taken 1 to 1½ hours after meals, unless otherwise directed by your health care professional. However, patients with a condition known as achlorhydria may not absorb calcium supplements on an empty stomach and should take them with meals.
For individuals taking the chewable tablet form of this dietary supplement:
For individuals taking the syrup form of this dietary supplement:
Take this dietary supplement only as directed. Do not take more of it and do not take it more often than recommended on the label. To do so may increase the chance of side effects.
The dose medicines in this class will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of these medicines. If your dose is different, do not change it unless your doctor tells you to do so.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.
Keep out of the reach of children.
Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.
Do not keep outdated medicine or medicine no longer needed.
If this dietary supplement has been ordered for you by your health care professional and you will be taking it in large doses or for a long time, your health care professional should check your progress at regular visits. This is to make sure the calcium is working properly and does not cause unwanted effects.
Do not take calcium supplements within 1 to 2 hours of taking other medicine by mouth. To do so may keep the other medicine from working properly.
Unless you are otherwise directed by your health care professional, to make sure that calcium is used properly by your body:
Some calcium carbonate tablets have been shown to break up too slowly in the stomach to be properly absorbed into the body. If the calcium carbonate tablets you purchase are not specifically labeled as being "USP," check with your pharmacist. He or she may be able to help you determine which tablets are best.
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Although the following side effects occur very rarely when the calcium supplement is taken as recommended, they may be more likely to occur if it is taken in large doses, if it is taken for a long time or if it is taken by patients with kidney disease.
Check with your doctor as soon as possible if any of the following side effects occur:
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.