by Mary Saucier Choate, M.S., R.D., L.D.
Dietitian and Co-op Food and Nutrition Educator
Calcium is an important nutrient. It is involved in supporting a healthy heartbeat, nervous system, hormones, normal blood clotting, and building strong bones. We lose calcium daily through skin, nails, hair, sweat, urine, and feces. We have to consume calcium in the foods and beverages we eat because our body cannot make it. If we don’t get enough calcium in our diet, our body takes it from storage– our bones.
The latest recommendation for adults is 1,000 to 1,300 mg (milligrams) of calcium each day. Like every dietary supplement, before taking calcium, consumers should look at what they are already eating to see if they are getting enough calcium. Of course, dairy products such as milk, yogurt, and cheese provide good sources of calcium. Calcium-fortified foods such as orange juice, bread, cereals, and sport bars among other fortified foods can also help to fill the calcium gap. If you are not able to eat enough calcium–rich foods, you may need to consider a supplement.
Look for the calcium percentage listed at the bottom of the Nutrition Facts panel and replace the percentage symbol with a zero. Nutrition labels show calcium as a percentage of 1,000 milligrams, the Daily Value for calcium.
For example, if a product label shows Calcium 30%, a serving of the product contains 300 milligrams of calcium.
20% DV of calcium equals 200 mg calcium.
15% DV of calcium equals 150 mg calcium.
In addition to dairy products and other calcium-rich foods, the typical diet contains foods with smaller amounts of calcium. According to the National Osteoporosis Foundation, these smaller amounts add up to about 250 mg in a typical diet. When you calculate the amount of calcium you’re getting each day, be sure to add 250 mg to the total.
There are many different kinds of calcium supplements, including: calcium carbonate, calcium phosphate, calcium citrate.
Each of these contains different amounts of elemental calcium, which is the actual amount of calcium in the supplement. Consumers must read the label carefully to determine how many tablets will provide the amount of calcium they need.
The “best” supplement for a person is the one that best meets your needs and lifestyle. This may take some experimentation. In some people, certain calcium supplements may cause gas or constipation. A different brand or form of calcium may not have these side effects.
Some supplements, such as calcium carbonate, contain more calcium per pill than others, such as calcium citrate, so fewer pills are needed. If you are someone who doesn’t like to take pills, or who is too busy to remember to take them throughout the day, a supplement that gives you what you need in fewer doses may be best.
Be aware-expensive does not equal more effective. Calcium carbonate is the least expensive and a store brand is just as effective as a pricey name brand.
Supplements made from unrefined oyster shell, bone meal, or dolomite may contain high levels of lead or other toxic metals.
The body best absorbs calcium in amounts of 500 milligrams at a time. Taking more that this at once will not result in more being absorbed, but taking it all at once is better than not taking it at all.
Studies have shown that the body can easily absorb most calcium supplements. If you are worried about absorbability, chewable or liquid calcium supplements are a good choice because they are already broken down and ready to be absorbed before they even enter the stomach. In non-chewable tablet form, calcium carbonate is absorbed best when taken with food. Calcium citrate can be taken anytime.
You can easily test how well your supplement dissolves by doing a simple test. Placing the supplement in a small amount of clear vinegar for 30 minutes and stir it occasionally. This creates an acidic environment similar to that of your stomach. If it doesn’t dissolve in a half hour, it probably will not dissolve in your stomach.
If medication you are taking needs to be taken on an empty stomach it should not be taken at the same time as your calcium supplement. Calcium supplements may reduce the absorption of some medicines, such as the antibiotic tetracycline and thyroid medication, and it can interfere with iron absorption. So take your calcium supplement at least two hours apart from these.
If you are taking proton pump inhibitors such as Prevacid®, Prilosec® and Nexium®, calcium citrate supplements may be a better calcium choice. These medications block stomach acid, and calcium citrate does not need stomach acid for absorption.
Calcium supplements are often sold in combination with vitamins and other minerals. For example, vitamin D is necessary for the absorption of calcium, but the two do not need to be taken together to be absorbed and used by the body. The same goes for minerals such as magnesium and phosphorus.
NIH Osteoporosis and Related Bone Diseases ~ National Resource Center
National Osteoporosis Foundation
Toll Free Number: 1 (800) 231-4222