Get a good quality multivitamin and start taking it with amino acids like tryptophan, 5-htp or theanine. There's an excellent book called "The Mood Cure" by Julia Ross that explains it all. I also think some of us might have problems absorbing nutrients. I noticed with myself that only when I upped my dose significantly with the supplements I was taking did I start getting results. To try and fix this absorption problem I'm now taking probiotics and digestive enzymes.