The awareness of folic acid as a necessary supplement for pregnant women has made spina bifida almost a thing of the past.  Spina bifida is "the most common permanently disabling birth defect in the United States."  It has a genetic component, but 70% of spina bifida can be prevented by taking folic acid.  That's pretty impressive work, for one little vitamin pill!

The tricky thing, of course, is that you have to be taking the folic acid at the time of conception.  Considering that "half of all pregnancies in the United States are accidental," this leads to the recommendation that all women of childbearing age should take a folic acid supplement.

Unfortunately, there is a down side.  Emerging information is that if you take too much folic acid, or for too long, it significantly increases your risk of getting cancer.  Now, many women would no doubt be happy to take on a slightly increased risk of cancer, if it meant preventing their babies from being born without a brain, or with an open spinal canal. However, not everyone is aware of the risk of taking too much folic acid - and most of us don't realize that we're already getting a pretty hefty folic acid supplement in our processed foods.

Folic acid is the artificial version of the naturally occurring folate.  Folate is in such small amounts in food that it can easily be processed by the body.  However, when you take a folic acid supplement - or eat something which has been supplemented with folic acid - it may overwhelm your body's ability to process that much, that fast.  It goes into your bloodstream until your liver can deal with it, and it may be these high levels of circulating folic acid in the bloodstream which cause the problems.

If you are planning a pregnancy, then you should definitely follow your obstetrician's advice about folic acid.  The risk of spina bifida is just too great to trifle with.  However, if you don't plan to get pregnant, then maybe you don't need to take an actual supplement.

There is a long list of foods which contain folate naturally. In fact, I think you would be hard put to buy a vegetable from the produce aisle that didn't have folate in it.  Here's a list I found at About.com.  And I can't help but notice that these foods have a lot of other good stuff in them, too!  

By the same token, I can't help but notice that the processed foods which contain folate (like breakfast cereal) are not necessarily super great for you.  It's all too easy to get too much folic acid from processed foods, and if you happen to take a multivitamin as well, then you could easily be overdosing on folic acid without even realizing it.

It doesn't seem to be possible to overdose on folate from natural sources.  Folate is processed a little bit differently in the body, and it isn't present in such over-the-top doses.  Plus, how much spinach are you really going to eat every day?  If you're eating three heads of spinach, then I suggest that a folate overdose is the least of your problems.

What it all comes down to is yet another proof of Michael Pollan's hypothesis that "nutritional science" and vitamin supplements (rather than eating healthy foods) is a big mistake.

Creative Commons-licensed image courtesy of Flickr user Andurinha