Vitamin D has been called the new "wonder vitamin." Doctors are learning more and
more about its role in good health and the prevention of diseases. Unfortunately,
though, most teens don't get enough.
Why Do I Need It?
Vitamin D plays a part in the bone-building process by helping the body to absorb
calcium. If someone doesn't get enough, it could affect the body's ability to build
and maintain strong bones and teeth.
It's not just about bones, though. Vitamin D is needed for a healthy immune system
— helping the body to fight off infections and prevent the development of autoimmune
diseases like rheumatoid arthritis. Research done in adults suggests that getting
enough vitamin D may help lower the chances of developing heart disease, certain cancers,
and other serious diseases like diabetes.
Why Don't People Get Enough?
There are several reasons why people don't get enough vitamin D:
Less exposure to UV rays. Vitamin D is sometimes called the "sunshine"
vitamin. When the sun's ultraviolet rays penetrate bare skin, it sets off a process
in the body that produces vitamin D. As many of us spend more and more time on
computers and game consoles, we're not outdoors as much as we once were. And, when
we do spend time in the sun, more of us are making the wise decision to use sunscreen
to block the UV rays that cause sun damage and cancer. Where we live makes a difference,
too: If you live in northern U.S. and Canada, it's possible you're not getting the
UV exposure required for your body to make enough vitamin D.
Dark skin. The melanin (the pigment that gives skin its color) in
darker skin protects against sun damage, but it can also block the sun needed to produce
Certain health conditions. Some health conditions, like cystic
fibrosis or inflammatory bowel
disease, affect how well the body absorbs nutrients, including vitamin D. And
because vitamin D is a fat-soluble vitamin that gets stored in the body's fat cells,
obesity increases a person's
risk for vitamin D deficiency.
Lower consumption of D-rich foods. Experts recommend eating vitamin
D-rich foods as the best way to get enough vitamin D. But many of the best foods —
like fatty fish and oil — are not the most popular. These days, most milk is
"fortified" with added vitamin D. But many teens aren't drinking enough milk to get
the recommended daily amount.
How Much Vitamin D Do I Need?
The Institute of Medicine (IOM) recommends that teens get 600 IU (international
units) of vitamin D per day. Ask your doctor if you should take a daily multivitamin
or vitamin D-only preparation that contains the 600 IU of vitamin D you need.
You may need even more than 600 IU if you have darker skin, live in areas with
limited sunshine, have a condition that affects how well your body absorbs nutrients,
or if tests show you have low vitamin D levels. Check with your doctor before taking
higher doses, though. Vitamin D is a fat-soluble vitamin, meaning it gets stored in
the body. In rare cases extremely large doses could build up to dangerous levels.
The IOM recommends an upper limit — the highest daily intake that
is likely to pose no risk — of 4,000 IU of vitamin D per day for teens. Most
people who eat foods rich in vitamin D, who get normal sun exposure, and who
take a 600 IU supplement will not get toxic buildup of vitamin D in their bodies.
Problems with vitamin D toxicity happen when people take supplements with megadoses
of the vitamin or lots of different supplements containing the vitamin.
As always, your doctor is the best advisor of what works for you!
Getting More Vitamin D Into Your Diet
As with all vitamins, it's best to get our D through the foods we eat. The best
sources of vitamin D are:
fatty fishes and fish oils, such as salmon, mackerel, and cod liver oil
vitamin D-fortified milk and other dairy products
Lots of other foods are fortified with vitamin D, including orange juice, soy milk,
cereals, and bread. Read the nutrition
facts label to see how much vitamin D is in each serving.