Growing up, I always drank milk with my meals. Actually, with the exception of my mother, so did the rest of my family. Even now, dare I say a grown up myself, I still find myself drinking milk with dinner (unless I'm eating fish, because the two just don't plain mix). Although I didn't realize it as a kid, or really care all that much at the time, those glasses of milk were helping me get the vitamin D I needed.

Because I live in the northeast, the colder months prevent us (or at least deter us) from being out in the sun as much as people living in warmer climates. As a result, we don't get our D from el sol. So, again, downing milk was and is a good thing. Why I mention all of this is to point out the fact that many people do not get enough vitamin D, as evidenced by the fact that their blood levels of this nutrient are far below what is considered healthy.

Harvard University researchers recommend that people consume at least 25 micrograms of vitamin D to help lower the risk of bone fractures, periodontal disease, colon cancer, and heart disease. To put that amount in perspective, it's about 20 mcg (800 IU) more than what the average person is currently consuming. And, while drinking milk is a good source of vitamin D, you should still try to get a little daily sunlight and perhaps even consider supplementation.