We carried out an exhaustive review regarding human skin color variation and how much it may be related to vitamin D metabolism and other photosensitive molecules. We discuss evolutionary contexts that modulate this variability and hypotheses postulated to explain them; for example, a small amount of melanin in the skin facilitates vitamin D production, making it advantageous to have fair skin in an environment with little radiation incidence. In contrast, more melanin protects folate from degradation in an environment with a high incidence of radiation. Some Native American populations have a skin color at odds with what would be expected for the amount of radiation in the environment in which they live, a finding challenging the so‐called “vitamin D–folate hypothesis.” Since food is also a source of vitamin D, dietary habits should also be considered. Here we argue that a gene network approach provides tools to explain this phenomenon since it indicates potential alleles co‐evolving in a compensatory way. We identified alleles of the vitamin D metabolism and pigmentation pathways segregated together, but in different proportions, in agriculturalists and hunter‐gatherers. Finally, we highlight how an evolutionary approach can be useful to understand current topics of medical interest.

中文翻译：

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美洲原住民皮肤色素沉着和维生素 D 基因的适应和共同适应

我们对人类皮肤颜色的变化及其与维生素 D 代谢和其他光敏分子的关系进行了详尽的审查。我们讨论了调节这种可变性的进化背景和假设来解释它们；例如，皮肤中的少量黑色素会促进维生素 D 的产生，从而有利于在辐射较少的环境中拥有白皙的皮肤。相比之下，更多的黑色素可以保护叶酸在辐射率高的环境中免于降解。一些美洲原住民的肤色与他们生活环境中辐射量的预期不一致，这一发现挑战了所谓的“维生素 D-叶酸假说”。由于食物也是维生素 D 的来源，还应考虑饮食习惯。在这里，我们认为基因网络方法提供了解释这种现象的工具，因为它表明潜在的等位基因以补偿方式共同进化。我们确定了维生素 D 代谢和色素沉着途径的等位基因，它们在农学家和狩猎采集者中分离在一起，但比例不同。最后，我们强调进化方法如何有助于理解当前的医学兴趣主题。