Figure 4
From: Melatonin the "light of night" in human biology and adolescent idiopathic scoliosis
![Figure 4](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2F1748-7161-2-6/MediaObjects/13013_2007_29_Fig4_HTML.jpg)
Age variations of melatonin levels. The hormone secretion increases in early childhood. In adolescent there is a decrease of the hormone concentration. The levels continued to decline gradually during middle age. In old population the levels of melatonin in serum are very low. (Modified from [88]).