Historical migration and contemporary health
研究过去500年的人口迁移如何通过维生素D缺乏机制影响当代健康，发现迁移导致的维生素D缺乏风险能预测当前地区健康指标。
Abstract We argue that migration during the last 500 years induced differences in contemporary health outcomes. The theory behind our analysis builds on three physiological facts. First, vitamin D deficiency is directly associated with higher risk of all-cause mortality. Second, the ability of humans to synthesize vitamin D from sunlight (UV-R) declines with skin pigmentation. Third, skin pigmentation is the result of an evolutionary compromise between higher risk of vitamin D deficiency and lower risk of skin cancer. When individuals from high UV-R regions migrate to low UV-R regions, the risk of vitamin D deficiency rises markedly. We develop a measure that allows us to empirically explore the aggregate health consequences of such migration in a long historical perspective. We find that the potential risk of vitamin D deficiency induced by migration during the last half millennium is a robust predictor of present-day aggregate health indicators.