I am of an age where everyone I know uses vitamins. My yearly blood tests don't show any deficiencies. My nails don't break and my hair and bones seem to be healthy.

But hey! Maybe I could have MORE hair! Stronger nails! Brighter skin! Maybe I think it's all good, but how would I really know, since it's normal for me?

How do I know if I am missing out? How would I judge success?