Examination of the relationship between pigmentation, UV addiction and vitamin D

Abstract

In the following paper, the Authors aim to describe the complex relationship between pigmentation, UV addiction and vitamin D and their evolutionary connections based on recent advances in research. It has been long suggested that prolonged UV exposure can induce addiction and a dependence-like state in some individuals, with β-endorphin released from keratinocytes in response to UV. An evolutionary benefit of UV addiction may be the promotion of vitamin D synthesis following chronic UV exposure. Vitamin D synthesis was also an evolutionary driver of the lighter skin in the Northern Hemisphere, so presumably the UV-induced addictive pleasant sensation may have once similarly facilitated the maximisation of vitamin D synthesis by increasing time spent under the sun. However, excessive UV exposure increases the risk of many skin cancers, so it is important to better understand vitamin D, pigmentation and the pleasurable effects that follow UV radiation.