Now that we're all treating our bodies like temples—or at least have heard of the concept—many of us start the day with a vitamin supplement. But did you know that by following a few simple rules, you can get more out of that one little pill than you otherwise might? Sheah Rarbach, R.D., a spokesperson for the American Dietetic Association, provides the following supplement-taking strategies: Make sure your supplement is up to snuff. To ensure this, look for one that sports the United States Pharmacopia (USP) seal of approval, says Rarbach. "This means it meets certain stan…