How much do you trust the vitamins and herbs you take?

Again, another serious question. As you all know, I’m a physician that does colonoscopies. I can’t tell you how many times I’ve done a scope and I’ve seen intact vitamins in the colon, indicating that they weren’t absorbed. Furthermore, if you read the article linked below, you’ll see that there are serious questions about the quality control of many herbal supplements.

My question is, to those of you who subscribe to this stuff, how do you know it’s what you think it is and how do you know you’re absorbing it? Without FDA oversight, how can you be sure? This is NOT a question of efficacy—and that’s not what I’m interested in here.

http://www.sciencebasedmedicine.org/new-concerns-about-the-safety-and-quality-of-herbal-supplements/