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What You Should Know About Calcium
Why Is Calcium Important?
Calcium is a mineral that is essential
for life, yet the majority of Americans
do not get adequate calcium on a daily
basis. Calcium plays an important role
in building stronger, denser bones early
in life and keeping bones strong and
healthy later in life.
About 99 percent of the calcium in our
bodies is found in our bones and teeth.
In addition to building and maintaining
healthy bones, calcium allows blood to
clot, nerves to send messages, muscles
to contract and other body functions.
Each day, our bodies lose calcium
through skin, nails, hair, sweat, urine
and feces. The human body cannot produce
calcium on its own. That’s why it’s
important to try to get enough calcium
through the foods we eat. When the diet
does not have enough calcium for our
body’s needs, calcium is taken from the
bones.
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Reading Food Labels
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To determine how much calcium is in
dairy, soymilk and other foods that have
calcium, check the nutrition facts panel
of
the food label for the daily value
(DV) of calcium. |
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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.
Usually only foods that come in
packages or containers have
food labels. |
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Sources of Calcium
Food remains the best source of calcium.
Dairy products are high in calcium,
while 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 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 under age 50 need 1,000 mg of
calcium and 400-800 IU of vitamin D3
daily.
Adults 50 and over need 1,200 mg of
calcium and 800-1,000 IU of vitamin D3
daily.
When available, choose a supplement of
vitamin D3 (cholecalciferol)
over vitamin D2
(ergocalciferol) to protect bone health.
People who get the recommended amount of
calcium from foods do not need to take a
calcium supplement. These individuals,
however, still may need to take a
vitamin D
supplement.
Getting too much calcium may increase
the chance of developing kidney stones
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.
Substances That Interfere with Calcium Absorption
There are several substances that can
interfere
with the body's ability to use calcium,
including:
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oxalate
protein
phytate sodium
caffeine
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Foods with high amounts of oxalate and
phytate reduce the absorption of calcium
contained in those foods. Spinach, rhubarb and beet
greens are examples of foods that are high in
oxalate. While these foods can be an important
part of a healthy diet, they are not good sources
of calcium.
Legumes, such as pinto beans, navy beans
and peas, are high in phytate. You can
reduce the phytate level in beans or legumes by
soaking them in water for several hours,
discarding the water, and then cooking them in fresh
water.
100% wheat bran is a food that provides
fiber but is also high in phytate. It is the
only food that appears to reduce the absorption of
calcium in other foods eaten at the same time
(for example, eating wheat bran cereal with
milk). If you are taking calcium supplements, you
may want to take them two or more hours
before or after eating any foods with 100% wheat
bran.
A diet that is too high in animal
protein, sodium, and caffeine can decrease calcium
absorption. A person’s daily calcium needs increase
when they get too much protein and sodium. You can offset the calcium loss from caffeinated
drinks such as coffee and tea by adding
milk or extra calcium to your diet. If you consume any
foods
or drinks that may interfere with
calcium absorption, you may want to take your
calcium supplements at a different time of day.
Calcium Supplements
The amount of calcium needed from a supplement depends on how much you
obtain
from your food. 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.
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
tolerance, convenience, cost and availability.
Calcium supplements are available without a
prescription in a wide range of preparations
(including chewable and liquid) and in various
strengths.
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NOF Calcium and Vitamin D
Recommendations |
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Children & Adolescents |
Calcium (Daily) |
Vitamin D (Daily) |
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1 through 3 years |
500 mg |
200 IU** |
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4 through 8 years
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800 mg
|
200 IU** |
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9 through 18 years |
1,300 mg |
200 IU** |
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Adult Women & Men |
Calcium (Daily)
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Vitamin D3 (Daily) |
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19 through 49 years |
1,000 mg |
400-800 IU |
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50 years and over |
1,200 mg |
800-1000 IU |
Pregnant & Breastfeeding
Women |
Calcium (Daily) |
Vitamin D3 (Daily) |
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18 years and under
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1,300 mg |
400-800 IU |
19 years and over
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1,000 mg
|
400-800 IU |
*When available, a supplement of vitamin
D3 is preferred over vitamin D2 to
protect bone health.
**NOF does not have specific vitamin D
recommendations for these age groups.
These are the recommendations of the
Institute of
Medicine of the National Academies and
National Institutes of Health, Office of
Dietary Supplements.
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:
Puddings
Homemade cookies
Breads or muffins
Soups or gravy
Casseroles
About two-to-four tablespoons
can be added to most recipes!
Combination Products
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 only
recommend
that people take multivitamins or
supplements
only when they are unable to get enough
nutrients from foods.
Purity
Calcium supplements prepared from
unrefined
oyster shell, bone meal or dolomite may
contain
lead or other toxic metals. Choose
supplements
that are 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.
Absorbability
The body easily absorbs most brand name
calcium products. Calcium supplements
need to dissolve in the stomach for
calcium to absorb. 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, whether from diet or
supplements, is
best absorbed when taken in amounts of
500 –
600 mg or less. Taking your calcium all
at once,
however, is better than not taking it at
all. Try
to get your calcium-rich foods and/or
supplements in smaller amounts
throughout the
day, preferably with a meal. Most
calcium
supplements should be taken with food.
Eating
food produces stomach acid that helps
your
body to absorb calcium. Supplements of
calcium
citrate absorb well taken at any time.
Tolerance
Side effects from calcium supplements,
such as
gas or constipation may occur. If
increasing
fluids and fiber 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 better tolerated if you start
with a
smaller amount. For example, start with
200-
300 mg of calcium a day for a week, and
drink
an extra 6-8 ounces of water with it.
Then
gradually add more calcium each week.
Calcium Interactions
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.
Also, 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.
Summary
Most studies show that low calcium
intake is
associated with low bone mass, bone loss
and
higher fracture rates (broken bones).
Getting
enough calcium is one of the many things
people can do to help reduce bone loss.
People
who get plenty of calcium during their
lifetime
may still be at risk for bone loss and
osteoporosis due to a variety of
factors. These
factors include vitamin D deficiency,
genetics
(family history), physical inactivity,
smoking,
alcohol abuse, and certain medications
and
medical disorders known to cause bone
loss.
Go to
Prevention Index
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