Calcium: What You Should Know
Why Is Calcium Important?
Calcium is a mineral that is necessary for life, yet many Americans do not get the amount of calcium they need every day. Calcium is important to build stronger, denser bones early in life and to keep bones strong and healthy later in life.
About 99 percent of the calcium in our bodies is in our bones and teeth. In addition to building bones and keeping them healthy, calcium helps blood clot, nerves send messages, muscles contract and other body functions.
Each day, you lose calcium through your skin, nails, hair, sweat, urine and feces. Our bodies cannot produce calcium. That’s why it’s important to try to get enough calcium through the foods we eat. When we don’t get enough calcium for our body’s needs, calcium is taken from our bones.
Reading Food Labels
To decide how much calcium is in a particular food, check the nutrition facts panel of the food label for the daily value (DV) of calcium.
Food labels list calcium as a percentage of the DV. This amount is based on 1,000 mg of calcium per day. For example:
* 30% DV of calcium equals 300 mg.
* 20% DV of calcium equals 200 mg of calcium.
* 15% DV of calcium equals 150 mg of calcium.
In addition to dairy products and other calcium-rich foods, the typical diet contains foods with smaller amounts of calcium. 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.
Sources of Calcium
Food is the best source of calcium. Dairy products, such as low-fat and non-fat milk, yogurt and cheese are high in calcium. Certain green vegetables and other foods contain calcium in smaller amounts. For people who have trouble digesting dairy products because of lactose intolerance, lactose-free dairy products and lactase enzyme pills are also available.
Calcium-fortified foods and calcium supplements are helpful for people who are unable to get enough calcium in their diets. Some juices, breakfast foods, soymilk, cereals, snacks, breads and bottled water have calcium that has been added. If you drink soymilk or another liquid that is fortified with calcium, be sure to shake the container well as calcium can settle to the bottom.
Daily Calcium Recommendations
According to NOF recommendations:
* Adults age 50 and older need a total of 1,200 milligrams (mg) of calcium from all sources* and 800-1,000 international units (IUs) of vitamin D every day.
* Adults under age 50 need a total of 1,000 milligrams (mg) of calcium from all sources* and 400-800 international units (IUs) of vitamin D every day every day.
*This includes the total amount of calcium you get from both food and supplements.
People who get the recommended amount of calcium from foods do not need to take a calcium supplement. Some people, however, may still need to take a vitamin D supplement. There are two types of vitamin D supplements. They are vitamin D3 and vitamin D2. Previous research suggested that vitamin D3 was a better choice than vitamin D2. However, more recent studies show that vitamin D3 and vitamin D2 are equally good for bone health. Vitamin D3 is also called cholecalciferol. Vitamin D2 is also called ergocalciferol.
Getting too much calcium from supplements may increase the chance of developing kidney stones and other health problems in some people. According to most experts, the safe upper limit for total daily calcium intake from all sources is 2,000 – 2,500 mg.
The amount of calcium needed from a supplement depends on the amount of calcium you get from foods. If you get enough calcium from the foods you eat, then you don’t need to take a supplement. Taking more calcium than you need in supplements does not have added benefits and can even have some risks. You shouldn’t take supplements that you don’t need.
Calcium exists in nature only in combination with other substances called compounds. Several different calcium compounds are used in supplements, including calcium carbonate, calcium citrate, calcium lactate and calcium phosphate. These compounds contain different amounts of elemental calcium, which is the actual amount of calcium in the supplement.
It is important to read the product label carefully to determine how much elemental calcium is in the supplement and how many doses or pills to take. When reading the label, pay close attention to the “amount per serving” and “serving size.”
Many people ask which calcium supplement they should take. The best supplement is the one that meets a person’s needs based on convenience, cost and availability. Calcium supplements are available without a prescription in a wide range of preparations (including chewable and liquid) and in different amounts.
NOF Calcium and Vitamin D Recommendations
NOF Calcium and Vitamin D Recommendations
Children & Adolescents Calcium (Daily) Vitamin D (Daily)
1 through 3 years 500 mg 400 IU*
4 through 8 years 800 mg 400 IU*
9 through 18 years 1,300 mg 400 IU*
Adult Women & Men Calcium (Daily) Vitamin D (Daily)
19 through 49 years 1,000 mg 400-800 IU
50 years and over 1,200 mg 800-1000 IU
Pregnant & Breastfeeding Women Calcium (Daily) Vitamin D (Daily)
18 years and under 1,300 mg 400-800 IU
19 years and over 1,000 mg 400-800 IU
*NOF does not have specific vitamin D recommendations for these age groups. These are the recommendations of the American Academy of Pediatrics.
A Simple Way to Add Calcium to Many Foods
A single tablespoon of nonfat powdered milk contains about 50 mg of calcium. Try adding some to:
* Homemade cookies
* Breads or muffins
* Soups or gravy
About two-to-four tablespoons can be added to most recipes!
Other Vitamins and Minerals
Calcium supplements are also available in combination with vitamins and other minerals. Although vitamin D is necessary for the absorption of calcium, it does not need to be taken at the same time as a calcium supplement.
Minerals such as magnesium, phosphorus and vitamin K are also important for bone health, but are usually obtained by eating a well-balanced diet. Most experts recommend that people take multivitamins or supplements only when they are not able to get enough nutrients from foods.
Calcium supplements made from unrefined oyster shell, bone meal or dolomite may contain lead or other toxic metals. Choose supplements that are made by known brand names with proven reliability for these types of supplements.
If you are not familiar with the brand, look for labels that state “purified” or have the USP (United States Pharmacopeia) symbol. The “USP Verified Mark” on the supplement label means that the USP has tested and found the calcium supplement to meet certain standards for purity and quality. Because applying for the USP symbol is voluntary, many fine products may not display this symbol. The USP symbol is helpful when you don’t know the brand.
Talk with your healthcare provider or pharmacist about possible interactions between prescription or over-the-counter medications and calcium supplements. Here are a few examples:
* Calcium supplements may reduce the absorption of the antibiotic tetracycline.
* Calcium supplements should not be taken at the same time as iron supplements.
* Thyroid hormones should not be taken within four hours of calcium supplements to prevent interactions (unless directed otherwise by a healthcare provider or pharmacist).
* Medications that need to be taken on an empty stomach should not be taken at the same time as a calcium supplement.
* Consider calcium citrate supplements over other calcium supplements if you take proton pump inhibitors (PPIs) such as Prevacid®, Prilosec® and Nexium®. Because these medications block stomach acid, your body may better absorb calcium citrate which does not need stomach acid for absorption.
The body easily absorbs most brand name calcium products. Calcium supplements need to dissolve in the stomach for calcium to be absorbed. Chewable and liquid supplements dissolve well because they break down before entering the stomach. The USP symbol on the label also lets you know that the supplement will break down and dissolve so that the body can use it.
Calcium is absorbed best when taken in amounts of 500 – 600 mg or less. This is the case when you eat calcium rich foods or take supplements. Taking your calcium all at once, however, is better than not taking it at all. Because the average daily diet contains about 600 mg of calcium from foods, most people only need about 600 mg of calcium from supplements.
Try to get your calcium-rich foods and/or supplements in smaller amounts throughout the day, preferably with a meal. You should take most calcium supplements with food. Eating food produces stomach acid that helps your body absorb the calcium. The body can absorb supplements of calcium citrate at anytime. You can take calcium citrate supplements either with or without food depending on your preference.
Side effects from calcium supplements, such as gas or constipation may occur. If increasing fluids in your diet does not solve the problem, try another type or brand of calcium. It may require trial and error, but fortunately there are many choices.
When starting a new calcium supplement, it may be tolerated better if you start with a smaller amount. For example, start with 200-300 mg of calcium every day for a week, and drink an extra 6-8 ounces of water with it. Then gradually add more calcium each week.
Most studies show that low calcium intake is associated with low bone density, bone loss and higher numbers of broken bones. Getting enough calcium is one of the many things you can do to help reduce bone loss. People who get plenty of calcium may still be at risk for bone loss and osteoporosis due to a variety of factors. These include vitamin D deficiency, family history, physical inactivity, smoking, alcohol abuse and certain medications and medical disorders known to cause bone loss.