Flannery and Vitamin D

Since she'll never tell, I should let you all know that Flannery is kicking butt in grad school. She got an "A" on her first paper, missed .5 points on her first exam (scoring 20 points above the average), and answers other people's questions in review sessions. I'm not really sure when she does her work. I'm the one who is staying up all night to write papers for my one class.

She's also learning lots of interesting stuff. A lot of it is stuff we already knew: hydrogenated oils are bad, potatoes have very little nutritional value, and there are very few grocery stores in low income neighborhoods. Some things we didn't know but aren't that surprising: Americans spend the most (fruit) money on oranges, eat the most servings of apples, and buy the most pounds of bananas. And some things are downright surprising and I wonder why I haven't heard of them earlier. Take vitamin D for example. I knew that milk was fortified with Vitamin D and that you "get" it by exposing your skin to sunlight - end of story.

Well, our dinner conversation last night revolved around everything I didn't know about vitamin D.

The problem: Most Americans are deficient in Vitamin D. This deficiency is associated with many serious health issues, including many cancers.

How we get it: liver, cod liver oil, and produced when our skin is exposed to sunlight. In addition, fortified stuff such as a milk and dry cereal since most of us don't eat enough liver or cod liver oil, or get enough sun exposure*.

*Sun exposure: Our bodies produce vitamin D when our skin is exposed to sunlight - specifically UVB rays. You only need to get ~15 minutes of exposure a day. In addition, vitamin D is fat soluble, so our bodies store it for months. Therefore, if you skip your 15 minutes a day, but stay out 30 minutes the next, you are set. Problem #1 - Sunblock blocks UVB rays (skin cancer from sun burns vs lots of cancers "associated" with vitamin D deficiency). Problem #2 - Those who live above the 37th latitude don't get any UVB rays during the 4 months of winter (all of us that live in Michigan). Problem #3 - The fifteen minutes a day is for Caucasians. African-Americans need lots and lots more of exposure a day because their dark skins blocks out the rays.

RDA: Right now, the RDA is 200 units a day (this is 4 cups of fortified milk a day). The American Ass. of Public Health (don't quote me the organization - I may have the name wrong) is recommending we bump the RDA up to 1000 units a day.

Interesting fact: A a study of white, middle-aged doctors found them to have no issues with Vitamin D deficiency. The explanation - winter trips to the Caribbean and lots of golfing.

So, in addition to eating piles of vegetables each night, putting sesame seeds in burritos, and banning juice, I think we may end up acquiring a sun lamp. Of course, as Jeff says, how will we ever know if anything we limited or pilled on makes any difference in the end.