Having adequate tetrahydrobiopterin to make 5-hydroxytryptophan, instead of toxic and probably carcinogenic kynurenine, is ideal. The 5-hydroxytryptophan (5-HTP) goes on to make serotonin and eventually melatonin. Eight hours of sleep in the dark is another great way of helping to ensure that tryptophan goes down the good path to melatonin. thereby staying away from carcinogenic potential mediated through kynurenine's poisoning of VSOH. Melatonin's production is evident in that sleepy period right after eating our Thanksgiving turkey. Having apple (pectin) pie with turkey, makes “a good thing” better. How American is that, and how strange that such insights arose in Albuturkey.