Bone Basics
© 2008 NOF
National Osteoporosis Foundation
1232 22nd Street, NW · Washington, DC 20037 · (202) 223-2226 · www.nof.org
BUILDING BONES TO LAST A LIFETIME
Peak Bone Mass
Throughout your life, you constantly lose old
bone and make new bone. Children and
teenagers make new bone faster than they
lose old bone. Even after they stop growing
taller, young people continue to make more
bone than they lose. Their bones increase in
density until they reach what experts call
peak bone mass.
Peak bone mass is the point when you have
the greatest amount of bone you will ever
have. It usually happens between the ages of
18 and 25. By age 18, bone growth is nearly
complete. A small amount of additional bone
growth may continue until about age 25.
Having higher peak bone mass means that
you are less likely to break a bone or to get
osteoporosis later in life. On the other hand,
having lower peak bone mass increases your
chance of getting osteoporosis.
How Bones Change with Age
After you reach peak bone mass, you may
slowly start to lose more bone than you
make. At midlife, bone loss usually speeds up
in both men and women. Osteoporosis
happens when you lose too much bone, make
too little bone or both. When you have
osteoporosis, your bones become weak and
break more easily.
Although you can improve your bone health
atanyage,i
t
’
si
mpor
t
antt
ogrow and build
strong healthy bones when you are younger.
Younger people with lower bone density will
have less bone to lose when they are older.
For many women, a rapid loss of bone takes
place during the five to seven years after
menopause when estrogen levels drop
sharply. Some women lose up to 20 percent
or more of their bone density during this
time. After that, bone loss tends to take
place more slowly.
Osteoporosis is less common in men than in
women for several reasons. Men have larger
bones and their bone loss generally starts
later in life. They do not have the rapid bone
loss that women have after menopause.
However, decreasing testosterone levels with
age can cause men to lose bone. In their
later years, many men have bone loss that
equals that of women.
What Influences Peak Bone Mass
There are many reasons that some people
have higher peak bone mass than others.
Below are the main ones:
Gender — Peak bone mass tends to be higher
in men than in women.
Race — African-American women are more
likely to have higher peak bone mass than
Caucasian women. African-American men
also have higher peak bone mass than
Caucasian men.
Family History — People who have family
members, especially parents, with osteoporosis
tend to have lower peak bone mass. Research
suggests that if either of your parents had
osteoporosis or broken bones as an adult,
you are more likely to get it too.
Hormones — In women, estrogen helps to
build strong bones and keep them healthy. It
plays an important role in peak bone mass
too. In teen girls and young women with
anorexia nervosa or other eating disorders,
estrogen levels may drop and cause menstrual
periods to stop. As a result, teens with eating
disorders or who often miss periods may build
less bone and have lower peak bone mass.
In teen boys and young men, testosterone
helps to build and protect bone. When testosterone levels are low, the male body builds
less bone and peak bone mass is lower.
Calcium and Vitamin D — Calcium helps
children build strong bones and helps adults
keep their bones healthy. To absorb calcium,
our bodies need vitamin D. Getting enough
calcium and vitamin D every day is important
at all ages. When chi
l
dr
enandt
eensdon’
tget
enough, they are more likely to have lower
peak bone mass.
Staying Active — Our bones need exercise
and physical activity to grow and stay strong.
High impact activities build the strongest
bones in children and teens. Some examples
are basketball, dancing, gymnastics, jumping
rope, running, soccer and tennis.
Weight lifting and resistance machines are
also good for the bones. While bicycling
and swimming are healthy forms of exercise,
t
heydon’
tpr
ovi
demuchbenef
i
tt
ot
hebones.
Habits and Behaviors — The habits of
children and teens can make a difference in
their peak bone mass. These habits are also
important for the bone health of adults.
Smoking and drinking too much alcohol are
bad for the bones. Also, too much caffeine
and salt and too many soft drinks may lead
to lower peak bone mass.
Helping Children Build Strong Bones
Adults can help the children in their lives
grow and build strong bones in many ways:
 Serve as positive role models for children
and teens. Beact
i
ve,don’
tsmokeand
limit alcohol use. Eat a balanced diet with
fruits and vegetables, and include foods
that have calcium and vitamin D. Take
supplements of calcium and vitamin D if
needed.
 Find and encourage ways for the children
in your life to be more active, such as
walking to school, participating in sports,
dancing, taking stairs instead of elevators
and doing family activities such as hiking.
National Osteoporosis Foundation
Calcium and Vitamin D
Recommendations
Age
Calcium
Vitamin D
Daily
Needs
Daily
Needs
1 –3 years
500 mg
400 IU*
4 –8 years
800 mg
400 IU*
9 –18 years
1,300 mg
400 IU*
19 –49 years
1,000 mg
400–800 IU
50+ years
1,200 mg
800–1,000 IU
Pregnancy/
Breastfeeding
14 - 18 years
1,300 mg
400–800 IU
Pregnancy/
Breastfeeding
19+ years
1,000 mg
400–800 IU
*The National Osteoporosis Foundation (NOF)
does not have specific vitamin D recommendations for these age groups. These are
the recommendations of the American
Academy of Pediatrics (AAP).
______________
 Encourage children to take an active part
in selecting and preparing calcium-rich
foods. Take them grocery shopping and
encourage them to make healthy food
choices. Let them help plan and prepare
some of the meals.
 Watch for delayed sexual development,
as it may result in lower peak bone mass.
Girls who have not begun their menstrual
periods by age 16 or whose periods have
stopped for any reason should see a
heal
t
hcar
epr
ovi
der
.Boyswhodon’
tbegi
n
puberty by the age of 15 should also see a
healthcare provider.
Children are building bones to last a lifetime.
The higher their peak bone mass, the easier it
is to keep their bones strong and healthy as
they grow older.
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