Healthy Bones: Starting It Off Right
Jeremiah Clinton, MD
Although we focus on healthy bones as we age, we often overlook the importance
of the early years. Our bones reach their peak strength and size somewhere
between the ages of 25-30. There is a slow decline of our bone mass after
this, which can lead to the weakening of the bone and osteoporosis. That
is why it is so important that we have healthy bones when we are younger.
Probably the biggest factor to achieving peak bone mass and avoiding osteoporosis
is your genes. Genetics play a crucial role in the size and structure
of our bones. Although we do not have any control over our genes there
are things we can do at every stage of life to ensure our bones stay as
strong as possible.
Our childhood and adolescent years is the most important time for building
a strong skeleton, because of the rapid growth of our bones during this
time. When bones are growing they are laying down the architecture for
the future and maximizing our diet and exercise during this time can lead
to stronger healthier bones. We can also avoid habits such as smoking,
drinking excessive alcohol and inactivity to ensure we do not loose bone
mass during this critical period.
Calcium is an essential building block for our bones and is an important
mineral for the normal function of our bodies. One of the roles of our
skeleton is a storage bank for calcium. In times when our dietary intake
of calcium is less than what our bodies need, we will take that calcium
from our bones. That is why a healthy diet rich in calcium is so important
as we grow. However calcium alone is not enough. Vitamin D is responsible
for our intestines ability to absorb the calcium in our diet. Without
enough Vitamin D the calcium passes through our system and is not absorbed
in our intestines. Normally Vitamin D is produced in our skin by exposure
to the sun. As our culture has become more aware of the risks of excessive
sun exposure and have used sunscreen to lessen these risks, our body's
ability to produce Vitamin D is hindered. Similarly in northern climates
were we need to stay covered a large portion of the year to stay warm
we take away our bodies ability to make Vitamin D. Not surprisingly osteoporosis
becomes more prevalent the further away from the equator you get. That
is why supplementing calcium and vitamin D becomes very important to ensuring
healthy bones, especially as we grow.
With a healthy diet we can usually get enough calcium to support our bones.
As infants breast milk and formula provide us with adequate calcium. As
toddlers using whole milk for feeding is an excellent source of both calcium
and vitamin D. From ages 4-8 we can provide enough calcium in our diet
by eating about 2 cups of yogurt and a glass of milk per day. The most
critical time for ensuring healthy bones as adults is in our teens as
we go through puberty. Up to fifty percent of our calcium stores are acquired
during puberty for women and two-thirds in men. At the end of puberty
most girls have acquired 95% of their peak bone mass. Early or late onset
of puberty can have negative effects on our bone mass. Girls typically
start puberty at age 10 and boys around age 11. Peak growth occurs for
girls between ages 11-12 and 13-14 for boys. Growth typically stops in
boys at age 17-18 and 14-15 for girls. During these times of rapid growth
supplying our bodies with adequate calcium and Vitamin D is crucial. Unfortunately
many teens do not get enough calcium in their diet. The average teen needs
about 1300 mg of calcium per day, this is equivalent to a glass of calcium
fortified orange juice, a cup of yogurt and two glasses of milk per day.
Other nondairy sources of calcium include green leafy vegetables, tofu,
and fish. If we are unable to reach this goal then supplementing our diet
is necessary to ensure good bone health. It is recommended that everyone
from age 1-70 get at least 600 IU of vitamin D although more recent literature
supports 1000 IU of vitamin D per day. Our diets unfortunately are not
a good source of vitamin D (except for Vitamin D fortified milk which
has about 100IU of vitamin D per glass), therefore taking a daily supplement
is usually required to ensure adequate intake of vitamin D.
Exercise is the other key ingredient to building healthy bones when were
young. Weight bearing sports and exercise such as running, walking, soccer,
and gymnastics are a few examples of activities that will improve bone
density early in life. But overdoing it can also be harmful to your bones.
Young girls who exercise in excess can lose enough weight that it affects
their hormones. When this occurs they may stop having their periods because
of the lack of adequate estrogen as a response to the weight loss. The
loss of estrogen at a young age can lead to decrease bone production and
even loss of bone mass at a time when they should be maximizing their
peak bone mass. If a young women stops having their periods or begins
to have irregular periods in their teens or early 20s it is important
to see a doctor.
Through a healthy diet and an active lifestyle children and teens can
maximize bone production and strength ensuring healthy bones in the future.
And although this may not always prevent osteoporosis when we're older
it has been shown to significantly reduce the risk of osteoporosis and
the fractures associated with it. It is important to ensure that you and
your children maintain a healthy diet rich in calcium and vitamin D, with
possible supplements if needed, and exercise regularly to ensure a healthy
skeleton throughout life.
Questions and or comments regarding this week's health column please
contact Jeremiah Clinton, MD at Bitterroot Orthopedics and Sports Medicine,
a service of Marcus Daly Memorial Hospital, 1200 Westwood Drive, Hamilton,
MT 59840. Working together to build a healthier community!