Information about Calcium Supplements
Calcium is needed throughout your life. Most of your bone mass is built when you are a child or young adult. After the bone building period ends, bone mass must be maintained. The main way to build and maintain bone mass is to have a diet rich in calcium. Calcium is needed to keep bones strong and healthy and to reduce the risk of osteoporosis. It also helps maintain healthy teeth, normal blood clotting, and makes your heart and muscles work as they should.
How much calcium do I need?
The amount of calcium you need is based on age and stage in life. See Table 1 for the recommended daily calcium requirements of the National Institutes of Health (NIH) Consensus Panel.
Table 1. Calcium Requirements
| Population | Recommended Daily Intake |
Infants: birth to 6 months |
400 mg |
6 months to 1 year |
600 mg |
Children: 1-5 years |
800 mg |
6 – 10 years |
800 – 1200 mg |
Adolescents and Young Adults: 11-24 years |
1200 – 1500 mg |
Men: 25-65 years |
1000 mg |
>65 years |
1500 mg |
Women: 25 – 50 years |
1000 mg |
>50 years, postmenopausal on estrogen |
1000 mg |
>50 years, postmenopausal not on estrogen |
1500 mg |
>65 years |
1500 mg |
Pregnancy or nursing: |
1500 mg |
What is osteoporosis?
The word “osteoporosis” is made up of two parts: “Osteo” refers to bone. “Porosis” means porous. Osteoporosis refers to bones that have become weaker due to loss of calcium, protein and other minerals. The bone size will stay the same, but the outside walls of the bone become thinner. Because of this you can have:
- humpback posture due to weak bones in the spine,
- walking with a limp from a broken hip,
- (physical) pain,
- less ability to take care of yourself,
- poor quality of life
About 20 million women in the United States have osteoporosis, but it can also affect men. There are certain factors that make you more at risk for osteoporosis:
- Female
- White or Asian descent
- Low calcium intake
- Early menopause
- Lack of exercise
- Smoking
- Too much alcohol
- Low body weight or small frame
- Long-term steroid use
How do I prevent osteoporosis?
Changes in diet and lifestyle may help you reduce your risk of osteoporosis. Limit yourself to 2-5 drinks with caffeine per day. Stop smoking. Walking and weight-bearing exercise also can strengthen bones. Aim for at least 4 times per week for 30 minutes a day. Osteoporosis can be prevented and treated, but there is no cure.
A very good way to reduce your risk of osteoporosis and maintain healthy bones is to include plenty of calcium in your diet. If you are not getting enough, you should think about calcium supplements.
How much calcium is in the food that I eat?
The best food sources of calcium are milk and milk products. The Vitamin D and lactose in dairy products help to increase how much calcium your body absorbs. Foods that are good sources of calcium are listed in Table 2.
Table 2. Food Sources of Calcium
250 to 300 mg of Calcium 1 cup milk (whole, 2%, 1%, skim, chocolate or other flavor, dry milk) 1 cup yogurt 8 oz. calcium-fortified juice 1 oz hard cheese (parmesan or Swiss) 8 oz. milk shake 1 slice Wonder® calcium-enriched bread 2 pieces cheese pizza (1/4 of 14” pie) |
200 to 250 mg of calcium 1 oz. soft cheese (cheddar or brick) 1 cup macaroni and cheese, packaged |
150 to 200 mg of calcium 1 cup cottage cheese ½ cup au gratin potatoes 8 oz. fortified soy milk 5 oz. tofu, processed with calcium sulfate 1 cup cream soup made with milk 3 oz. salmon, canned with bones |
100 to 150 mg of calcium 1 cup broccoli ½ cup kale ½ cup oysters ½ cup ice cream or ice milk ½ cup custard ½ cup pudding, made with milk 1 cup sherbet ½ cup almonds, whole |
What else do I need to make my bones strong?
You need calcium for healthy bones. But, your bones must be able to absorb the calcium that you take. You must also have Vitamin D for your bones to absorb and use calcium. We get this from certain foods (fortified dairy products, fish oils, egg yolks) and sunlight. The recommended daily intake of Vitamin D is:
- 400 IU for those 50 – 70 years old
- 400 IU for those under 50 years old
Be sure that you do not take too much Vitamin D. It can be toxic if too much is taken. Do not exceed 800 IU daily without your doctor’s advice. Talk to your pharmacist or doctor if you need help knowing how much Vitamin D you need. The Vitamin D content of many forms of calcium supplements is listed in the right-hand column of Table 3.
What if I’m not getting enough calcium in my diet?
If you are not getting enough from your diet, you should strongly think about adding calcium tablets to your diet. You can find calcium supplements in many forms. The most common forms of calcium are calcium carbonate, calcium citrate, calcium gluconate, calcium phosphate, or calcium lactate. Each calcium supplement contains a different amount of elemental calcium. Table 3 lists the most common supplements with the calcium and Vitamin D content in each.
Table 3. Common Calcium Supplements
Calcium Supplement |
Amount of Elemental Calcium |
Amount of Vitamin D |
| Calcium carbonate |
|
|
Tums® Regular Strength |
200 mg |
None |
Tums® EX (Extra strength) |
300 mg |
None |
Tums® Ultra |
400 mg |
None |
Caltrate® |
600 mg |
None |
Caltrate® Plus |
600 mg |
200 IU |
Caltrate® Chewables |
600 mg |
200 IU |
Caltrate® 600 + D |
600 mg |
200 IU |
Viactiv®calcium chews |
500 mg |
100 IU |
| Calcium citrate |
|
|
Citracal® |
200 mg |
None |
Citracal® + D |
315 mg |
400 IU |
| Calcium phosphate |
|
|
| Posture–D® | 600 mg |
125 IU |
| Organic Calcium |
|
|
| OsCal® 500 + D (oyster shell calcium) | 500 mg |
200 IU |
| Multiple Vitamins** |
|
|
| One-A-Day®Women’s formula | 450 mg |
400 IU |
| One-A-Day®50+ formula | 120 mg |
400 IU |
| One-A-Day®Maximum formula | 162 mg |
400 IU |
| Centrum® | 162 mg |
400 IU |
** The multiple vitamins listed are most commonly used or compared to store brands. Make sure to check the brand of vitamins you take and include the calcium content when deciding the proper calcium supplement for you.
What about other medicines?
Calcium (supplements) may not mix well with other medicines. They may decrease the effects of iron, tetracycline, doxycycline, ciprofloxacin, etidronate, Alendronate, risedronate and phenytoin. Calcium should be taken at least 2 hours apart from any of these. Make sure to tell your doctor that you are taking calcium.
How do I take my calcium?
Calcium is best absorbed if taken with meals. Your dose should be split and taken throughout the day with 8 oz. of liquid. Chewable forms of calcium should be chewed well. They should not be taken at the same time as the medicines listed above, nor with antacids, high-fiber meals or bulk-forming laxatives.
Are there any side effects?
Side effects with the proper use of calcium are rare. Count the calcium you take in as part of your diet, and only take the amount that is needed to reach your recommended daily amount. You should stop taking the supplements and contact your doctor if you have any of these signs:
- blood in your urine,
- pain in your lower back or abdomen,
- needing to empty your bladder often.
Constipation and gas can also be problems with calcium use. Make sure you drink plenty of fluids and eat fiber to avoid these problems. If these measures are not helpful, try switching to a different form of calcium.
Other things to know
- Be sure to read the amount of elemental calcium contained in each tablet. Some brands list the calcium content in more than one tablet.
- If you use antacids or acid blockers often or have less stomach acid than normal, calcium citrate is a better choice for you.
- Store this and all other medicines out of the reach of children and in a cool, dry place.
- If you have any questions about the use of calcium or other medicines, please talk to your doctor, nurse or pharmacist.
The information provided should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Any duplication or distribution of the information contained herein is strictly prohibited.
Last Updated: 10/17/2012
Copyright © 02/12/2010 University of Wisconsin Hospitals and Clinics Authority. All rights reserved. Produced by the Department of Nursing. HF#5518
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