Eggs versus Chewable Vitamins: Which Intervention Can Increase Nutrition and Test Scores in Rural China?

Background. Despite growing wealth and a strengthening commitment from the government to provide quality education, a significant share of students across rural China still have inadequate access to micronutrient-rich regular diets. Such poor diets can lead to nutritional problems, such as iron-deficiency anemia, that can adversely affect attention and learning in school. Large scale policies in Northwestern China have attempted to tackle these nutritional problems using eggs.  The overall goal of this paper is to assess the impact of the government’s egg distribution program by comparing the effect on anemia rates of an intervention that gives students an egg per day versus an intervention that gives students a chewable vitamin per day. We will also assess whether either intervention leads to improved educational performance among students in poor areas of rural China. To meet this goal, we report on the results of a randomized controlled trial (RCT) involving over 2,600 fourth grade students from 70 randomly-chosen elementary schools in 5 of the poorest counties in Gansu Province in China’s poor Northwest region. The design called for random assignment of schools to one of two intervention groups, or a control group with no intervention. One intervention provided a daily chewable vitamin, including 5 milligrams of iron. The other mimicked the government policy by providing a daily egg. According to the findings of the paper, in the schools that received the chewable vitamins, hemoglobin (Hb) levels rose by more than 2 g/L (over 0.2 standard deviations). The standardized math test scores of students in these schools also improved significantly. In schools that received eggs, there was no significant effect on Hb levels or math test scores. Overall, these results should encourage China’s Ministry of Education (MOE) to look beyond eggs when tackling nutritional problems related to anemia in an education setting.