“…Schematic presentation of estimated circadian curves based on peak and trough values reported in the literature. Circadian variation curves are shown for the following components: ( a ) tryptophan [ 18 , 43 ], ( b ) total fats, triglycerides, cholesterol [ 25 , 32 , 47 , 48 , 50 , 51 , 52 , 53 , 55 , 56 , 58 , 59 ], ( c ) iron [ 53 , 67 , 70 , 71 ], ( d ) melatonin [ 41 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 ], and ( e ) glucocorticoids [ 24 , 89 , 90 , 91 , 92 , 93 , 94 ].…”