Vitamins and Minerals: Information about Calcium Supplements
Why do I need calcium?
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
Table 1. Calcium Requirements
Population Recommended Daily Intake
Infants: birth to 6 months *mg
6 months to 1 year *mg
Children: 1-3 years 700 mg
4 – 8 years 1000 mg
Adolescents and Young Adults:
Men: 19 to 50 years 1000 mg
51 to 70 years 1200 mg
Women: 19 to 50 years 1000 mg
51 to 70 years 1200 mg
Adults >70 1200 mg
Pregnancy or nursing: 1000 to 1300 mg
*See Institute of Medicine (IOM) or NIH web sites for adequate intake and upper intake levels of
What is osteoporosis?
The word “osteoporosis” is made up of two parts: “osteo” refers to bone and “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:
ξ Bones that break with normal activities (hip, spine or wrist)
ξ Humpback posture due to weak bones in the spine
ξ Walking with a limp from a broken hip
ξ (Physical) pain
ξ Less ability to take care of yourself
ξ 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:
ξ White or Asian descent
ξ Low calcium intake
ξ Early menopause
ξ Lack of exercise
ξ Too much alcohol
ξ Low body weight or small frame
ξ 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
to 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
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 (8 ounces) milk (whole, 2%, 1%, skim, chocolate or other flavor, dry milk)
1 cup (8 ounces) yogurt
1 cup (8 ounces) calcium-fortified juice
1 ounce hard cheese (parmesan or Swiss)
1 cup (8 ounces) milk shake
1 slice Wonder calcium-enriched bread
2 pieces cheese pizza (1/4 of 14” pie)
200 to 250 mg of calcium
1 ounce 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
1 cup (8 ounces) fortified soy milk
5 ounces tofu, processed with calcium sulfate
1 cup (8 ounces) cream soup made with milk
3 ounces 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:
ξ 400 to 800 IU (international units) for people over 70 years old
ξ 400 to 800 IU for those 50 to 70 years old
ξ 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
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
(100 or 200 mg, peds)
500 to 1000 IU
(400 IU, peds)
Citracal 200 mg None
Citracal + D 315 mg 400 IU
Posture–D 600 mg 125 IU
OsCal 500 + D (oyster shell
500 mg 200 IU
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 ounces 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:
ξ Pain when you empty your bladder
ξ Blood in your urine
ξ Pain in your lower back or abdomen
ξ You need 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.
Other things to know
ξ Do not take more than 1500 mg of calcium daily, without physician supervision
ξ Be sure to read the amount of elemental calcium contained in each tablet. Some brands list
the calcium content in more than one tablet.
ξ If you use antacids or acid blockers (ranitidine, cimetidine, famotidine, pantoprazole,
omeprazole, etc.) often or have less stomach acid than normal, calcium citrate is a better
choice for you.
ξ Store this and all other medicines out of the reach of children and in a cool, dry place.
ξ If you have any questions about the use of calcium or other medicines, please talk to your
doctor, nurse or pharmacist.
Your health care team may have given you this information as part of your care. If so, please use it and call if you
have any questions. If this information was not given to you as part of your care, please check with your doctor. This
is not medical advice. This is not to be used for diagnosis or treatment of any medical condition. Because each
person’s health needs are different, you should talk with your doctor or others on your health care team when using
this information. If you have an emergency, please call 911. Copyright © 12/2016 University of Wisconsin Hospitals
and Clinics Authority. All rights reserved. Produced by the Department of Nursing HF#5518