Calcium Supplements

Why is calcium important?

Calcium is a nutrient that is essential for strong bones and for supporting your body's vital functions such as controlling your blood pressure and maintaining your heart beat. 99% of your body's calcium is stored in your bones and teeth. This calcium makes up your bone bank. Throughout your life, calcium is deposited and withdrawn from your bone bank depending on your needs. When your dietary calcium intake is too low, your body will withdraw the calcium it needs from your bones to support your vital body functions. Over time, if more calcium is taken out of your bones than is put in, the result may be thin, weak bones that may break more easily as you age.

How do I know if I am getting enough calcium in my diet?

It is important to know your daily recommended calcium intake. The amount that you need each day varies according to your age.

*mg= milligrams
(Dietary Reference Intakes, National Academy of Science, 1997)

The preferred way to get adequate calcium is through a healthy, well-balanced diet. It is important to estimate the calcium in your typical daily diet.

If I am not getting enough calcium in my diet, what should I do?

• Most individuals can easily get at least half of the calcium they need from food. If your calcium intake is too low, try to increase the calcium in your diet. There are many calcium-rich foods to help you meet your calcium needs through diet alone. If you need expert advice about your individual nutritional needs, you may want to consider consulting with a registered dietitian/certified dietitian-nutritionist (RD, CDN). 
• To find a registered dietitian in your area, click on the American Dietetic Association website:  http://www.eatright.org/Public/ConferencesAndEvents/96_8140.cfm
• If you are unable to get enough dietary calcium on a daily basis, you may need a calcium supplement. If you need a supplement, it is important to select one that contains the proper amount of calcium. Your daily recommended calcium intake minus the estimated daily calcium in your diet will determine how much calcium to take from a supplement.

Is more calcium better?

• Some medical professionals may suggest slightly more calcium for individuals with certain medical conditions that interfere with the body's ability to use calcium efficiently.
• Although it is possible to consume too much calcium, studies show that most of the U.S. population does not consume enough calcium.  It is considered safe for most individuals to consume up to 2500 milligrams of calcium per day from foods and/or supplements. Some of the exceptions to this would be individuals with kidney stones or kidney disease and men with or at high risk for prostate cancer; both of these populations should meet but not exceed the recommended calcium intakes. It is important to speak to your medical professional about your individual calcium requirements and not to consume more than 2500 mg of calcium per day on a regular basis.  High calcium intakes on a regular basis may be harmful.  The adverse effects of excessive calcium intake may include high blood calcium levels, kidney complications and kidney stone formation.

How do I read the label of a calcium supplement?

Reading the label of a calcium supplement is quite simple. The supplement label lists the calcium content in milligrams (mg) per serving. It is important to check the serving size to find out how many tablets or capsules provide the specified amount of calcium. The label may refer to calcium as elemental calcium. This distinguishes the weight (mg) of calcium alone from the weight (mg) of the calcium compound (such as calcium carbonate, calcium citrate, calcium phosphate, or others).

What is the difference between the various calcium supplements?

In selecting the right supplement for you, it is important to consider how you intend to take the supplement. Calcium supplements are available in liquid powder, chewable or tablet forms. Taste may also a consideration; the taste of the supplement may determine whether you will take it on a regular basis.

What do the symbols on the labels of some calcium supplements mean?

There are a number of symbols to look for on the labels of calcium supplements. These symbols mean that a non-profit, scientific laboratory has tested the supplements.  Some of these symbols include the Consumer Labs International insignia, the NSF (NSF International) mark and the USP (United States Pharmacopeia) symbol. The symbols indicate that the calcium supplement has been tested to ensure it contains the ingredients listed on the label, that it is pure from lead and other metals, and that it will break down in your stomach. Calcium must dissolve in your stomach before it can be absorbed in your intestines and used by your body.

It is important to know that the application for any of these symbols is voluntary so many acceptable products may not display a symbol. If your supplement is not marked with a symbol, you can easily test it to find out if it will break apart.  Simply put the supplement into a glass of clear vinegar. Stir the solution occasionally. If the calcium supplement disintegrates within 30 minutes, it should do so in your stomach, too.  If the supplement does not completely break apart, choose another calcium supplement.  Be sure to discard the calcium/vinegar solution after the test.

Do I need to be concerned about lead in my calcium supplement?

One of the above symbols on the label of a calcium supplement indicates that it does not contain lead or other metals.  However, it seems that lead in calcium supplements is less of a concern than some believe. According to a recent laboratory analysis, calcium supplements, in the dosage prescribed for prevention and treatment of osteoporosis, contain much less than the safe level of lead. A further safeguard is that lead in calcium supplements is usually not well-absorbed because calcium blocks lead absorption.

Do I need vitamin D in combination with my calcium supplement?

Although Vitamin D is readily available in combination with calcium supplements, supplemental vitamin D should only be taken when your daily requirement for vitamin D is not met. There are certain populations at high risk for vitamin D deficiency including seniors over age 70, homebound individuals and people with gastrointestinal diseases that cause poor absorption of vitamin D. If you think that you may be at risk for vitamin D deficiency, speak to your doctor or medical professional about how to get enough vitamin D to promote healthy bones.

Do I need magnesium in combination with my calcium supplement?

Magnesium supplements are not required for most healthy individuals. Magnesium is plentiful in a healthy, well-balanced diet. However, certain individuals may be at risk for magnesium deficiency including those with gastrointestinal diseases that cause poor absorption or increased losses of magnesium, frail elderly individuals eating poor diets, alcoholics, individuals receiving chemotherapy and those taking high dose diuretics (water pills) that deplete magnesium.  Your medical professional will prescribe a magnesium supplement if it is necessary or if you have a disease or condition that causes magnesium deficiency.

Do I need additional vitamins or minerals in combination with my calcium supplement?

A well-balanced diet following the food-pyramid approach to good nutrition including adequate calcium and vitamin D is what you need to achieve and maintain healthy bones. For most healthy individuals, additional vitamins or minerals (such as magnesium, boron, vitamin K, selenium or others) in the form of supplements are not required for healthy bones. In fact, many of these nutrients will be present in a wholesome diet including five or more servings of fruits and vegetables a day.

How do I take my calcium supplement?

• It is important to read the labels of calcium supplements and follow the directions for use. Chewable calcium supplements should be chewed thoroughly and all calcium supplements should be taken with a full glass of water. For best absorption, most calcium supplements should be taken with food. Calcium citrate is an exception; it may be taken with or without food.
• It is best to spread out the calcium you consume from diet and/or supplements throughout the day. In fact, for most efficient absorption, it is recommended to consume 600mg of calcium or less at one time. For individuals who take more than 600mg per day of calcium from supplements, the dose should be split to improve calcium absorption.

Are there any special considerations if I take an iron supplement?

If your medical professional recommends an iron supplement and you are also taking a calcium supplement, it is important that your body absorbs both nutrients. For the best absorption of both iron and calcium, it is recommended to take your calcium supplement 2 hours before or after your iron supplement. You should not take them at the same time.

Is it a problem to take a calcium supplement while I am taking antibiotics?

Calcium interferes with the body's ability to use certain antibiotics, tetracycline for example. If your doctor or medical professional prescribes tetracycline, it is important for you to take it properly. Therefore, you should not take calcium supplements (and not eat calcium-rich foods) at the same time as taking tetracycline. Your antibiotic will work best if you take your calcium supplement (or eat calcium-rich foods) 2 hours before or after taking tetracycline. It is always important to speak to your pharmacist about the proper way to take your medication.

Can calcium supplements cause constipation?

Some people who take calcium supplements complain about constipation but it can usually be prevented. The best way to prevent constipation, is to eat more fiber in your diet from fruits, vegetables, and whole grain products as well as to drink 6 to 8 glasses of water each day. If these simple steps are not helpful enough, take a closer look at your diet to try to get more calcium from foods and less from supplements. Read the label for the amount of calcium in each dose. A lower dose calcium supplement may be better tolerated than a high dose supplement. For example, calcium carbonate has the highest amount of calcium per dose. Calcium citrate has less calcium per dose and calcium gluconate is one of the lowest dose options.