The impact of vitamin A supplementation in childhood on adult outcomes: An exploration of mechanisms, timing of exposure, and heterogeneous effects

There is now a critical threshold of evidence documenting the relationship between one's exposure to shocks in early life and outcomes in adulthood. Using Nepal's vitamin A supplementation program, this study provides additional insights on the mechanisms and differences in effects by the timing of the first exposure and across different groups. The program's sequential rollout between 1993 and 2001 and the age eligibility provide an exogenous variation in exposure to the program. I utilize that variation and data on more than 700,000 individuals from the 2011 census to estimate the program's causal effect on long-term health and educational outcomes. I find that the program reduced the probability of having a disability but had no effect on educational outcomes. The positive effects on disability seem to have improved marriage prospects. The program also had different effects on individuals based on their timing of the exposure to the program, with an early exposure strengthening the positive health effects. Effects also differed by the individual's gender and ethnicity. They were more pronounced for men and individuals from traditionally advantaged ethnic groups. The findings suggest that long-term effects can differ even when the take-up rate is similar for different segments of the population.