{"type":"rich","version":"1.0","provider_name":"Transistor","provider_url":"https://transistor.fm","author_name":"GiveWell Conversations","title":"Scrutinizing One of Our Longest-Funded Programs: April 2, 2026","html":"","width":"100%","height":180,"duration":2210,"description":"Vitamin A supplementation is one of the programs GiveWell has supported the longest, and we’re currently funding it in many African countries. The program has an unusually strong evidence base for reducing child mortality, with multiple randomized controlled trials. Yet, as is the case for most global health programs, the evidence for vitamin A supplementation has complex, unresolved questions, such as how well findings from decades-old trials apply today and the extent to which existing research has been influenced by publication bias. As GiveWell’s research team has grown over the last several years, we have expanded our capacity to carefully research these questions. In this episode, GiveWell CEO and co-founder Elie Hassenfeld speaks with Senior Researcher Stephan Guyenet about the evidence base for vitamin A supplementation, the complications in applying that evidence to our funding decisions, and how GiveWell has improved our cost-effectiveness estimates for the program.Elie and Stephan discuss:The evidence base for vitamin A supplementation: Evidence from rigorous trials shows that vitamin A supplementation can significantly reduce child mortality. However, most of these trials were conducted 30 to 40 years ago, when infectious disease rates and vitamin A deficiency were more prevalent, and a more recent large trial in India found a much smaller effect. As a result, we worked to resolve our uncertainties about the effect of vitamin A supplementation in the contexts where we’re supporting it today. How GiveWell worked through the complications: To address our questions about the existing evidence, we engaged in further research. This included an analysis focused on the specific diseases for which vitamin A supplementation reduces mortality, a novel dosing-frequency analysis conducted in consultation with an outside statistician, and an assessment of possible publication bias. What all of this means for grantmaking: While the trials report that vitamin A...","thumbnail_url":"https://img.transistorcdn.com/-u3xe4YYytsIA-MwiMODoBW-Emt4SwBumSBMmblDbUM/rs:fill:0:0:1/w:400/h:400/q:60/mb:500000/aHR0cHM6Ly9pbWct/dXBsb2FkLXByb2R1/Y3Rpb24udHJhbnNp/c3Rvci5mbS8wNTc2/MzVhY2UyNmY0ZTZl/MzYwNmZkOGVlMGU3/NDYyMC5wbmc.webp","thumbnail_width":300,"thumbnail_height":300}