The Effect of Geography and Vitamin D on African American Stature in the Nineteenth Century: Evidence from Prison Records
利用19世纪美国监狱记录中的身高数据，研究发现日照（维生素D生成）与黑人身高正相关，且黑人农民身高高于其他职业者，内战前黑人青少年身高增长，解放后反而下降。
The use of height data to measure living standards is now a well-established method in economic literature. Although blacks and whites today reach similar terminal statures in the United States, nineteenth-century African American statures were consistently shorter than those of whites. Greater insolation (vitamin D production) is documented here to be associated with taller black statures. Black farmers were taller than workers in other occupations, and, ironically, black youth statures increased during the antebellum period and decreased with slavery's elimination.