Lisa Bell, Know Your Numbers

Vitamin D is the only vitamin you don't have to get from food, because it is also a hormone.

You need at least 200 IUs of vitamin D each day.

You can eat it, take a supplement, or let your body manufacture it when you are in the sun, but however you get it, you need vitamin D for strong muscles, bones, and teeth.

Doctors say it is just as important as calcium, because without D, your body can't absorb the calcium.

If you are under 50 years old, you need 200 IU's every day -- 400 if you're 50 to 70 years old and 600 if you're over 70.

A little bit of sun or fortified dairy products are the easiest ways to get your vitamin D.