University of Basel — Scoping the Feasibility of Measuring Under-5 Mortality Effects of Vitamin A Fortification Program (August 2025)

Note: This page summarizes the rationale behind a GiveWell grant to the University of Basel. University of Basel staff reviewed this page prior to publication.

Published: December 2025

1. The organization

The principal investigator for this grant will be Prof. Armando Meier, Assistant Professor of Economics at the University of Basel, Switzerland, who will oversee the project’s research design and writing. Alessio Lombini (PhD candidate in Economics, Queen Mary University) will act as co-Principal Investigator, managing dataset assembly, data cleaning, and preliminary analysis.1

2. The intervention

Vitamin A supplementation (VAS) is the largest component of GiveWell's nutrition grantmaking.2 We are uncertain about the mortality impact of VAS in modern contexts, in part because most of the VAS trials we rely on to estimate the impact of VAS on mortality in children under 5 are from the 1980s-90s.3

2.1 Does vitamin A supplementation work?

We believe VAS is probably effective for reducing under-5 mortality in modern contexts where vitamin A deficiency is common, though we estimate that it is substantially less effective today than it was when most of the VAS trials were conducted. We review the evidence in depth in our intervention report on VAS.

3. The grant

In June 2024, we launched a request for proposals (RFP) with Coefficient Giving (previously known as Open Philanthropy) focused on what we call "value of information" opportunities. We were seeking to fund research that can answer our high-priority grantmaking questions, and ultimately affect our future funding decisions.

Dr. Armando Meier at the University of Basel submitted a proposal responding to that RFP that proposed to evaluate the impact of a vitamin A fortification program on multiple outcomes. We do not provide additional detail about the proposed study in this document to protect the confidentiality of Dr. Meier’s work.

We think this study is potentially promising as a way to refine our estimate of VAS effectiveness, but Dr. Meier is unsure whether the data will allow estimation of under-5 mortality effects, which are our primary interest. Additionally, we have reservations about the long timeline (4 years) of the project.

To address these reservations, we asked Dr. Meier for a concise proposal to

1. scope the feasibility of measuring under-5 mortality effects,
2. define an identification strategy for under-5 mortality effects, and
3. propose investigation plan options at different levels of time and financial commitment.

Upon receiving Dr. Meier’s proposal, we will review it and decide whether or not to move forward with the full study.

3.1 Budget for grant activities

Scoping Budget4

Line item	Amount
PhD student (0.30 FTE = 0.5 years); data merging, cleaning, preparation, first analysis5	$9,860

4. The case for the grant

We are recommending this grant because:

• This grant is very small ($9,860), has a short timeline (about 6 months), and brings us closer to having a less uncertain estimate of the impact of vitamin A interventions in modern contexts, which would be a high-value outcome.
• The value of the scoping project depends on the value of the larger study it will help us evaluate. We think the larger study would potentially be valuable because:
  • We have a lot of uncertainty about the impact of VAS (and fortification) on under-5 mortality, health, and long-term economic outcomes in modern contexts.6
  • We think there is a good chance the larger study could reduce that uncertainty. We do not provide additional detail in this document to protect the confidentiality of Dr. Meier’s work.

4.1 Cost-effectiveness

Due to the small size of this grant, we did not explicitly model cost-effectiveness. However, we think it is likely to be very cost-effective because it moves us closer to addressing a major uncertainty about one of our largest grantmaking areas.

5. Risks and reservations

Our main reservations about this grant are:

• We may decide to move forward with the full study on the basis of scoping results, and that could be a mistake. For example, we may end up with a biased, unusable, or hard-to-interpret estimate. It may be hard for us to evaluate whether the estimate is biased and whether/how to use it in our model. However, this scoping project will help us evaluate that, and funding it does not commit us to funding the larger study.
• Measuring under-5 mortality may not be feasible, or the measure may not be high-quality.
• The study would be of vitamin A fortification, not supplementation. This introduces additional uncertainty if we plan to extrapolate the effect size to VAS. Given our level of uncertainty about VAS, we nevertheless think it would be a useful signal. We may also support vitamin A fortification at some point in the future.

6. Plans for follow up

We plan to check-in with Dr. Meier during the scoping phase to help ensure the proposal aligns with what we’re looking for. We expect to receive a report on the project’s findings in about six months. We expect to make a funding decision for the larger study within twelve months.

7. Internal forecasts

For this grant, we are recording the following forecasts:

Confidence	Prediction	By time	Resolution
40%	Univ. of Basel is able to complete the evaluation in 6 months from approval.	Q1 2026
40%	Accurately measuring u5 mortality is not feasible.	Q2 2026
50%	We fund the full study by the end of 2026	End of 2026
33%	If we move forward with the full study, it proves to be a mistake. Results are unconvincing or hard to interpret.	End of 2031
60%	If we move forward with the full study, we incorporate its results into the VAS CEA.	End of 2031

8. Our process

This was a quick grant investigation that grew out of the RFP project.

• We reviewed materials submitted by the applicants and independently read scientific papers to evaluate the proposed research.
• GiveWell research team members with relevant backgrounds shared their perspectives on the cost and timeline of the project.

9. Sources

Document	Source
"About me," Armando N. Meier	Source (archive)
Armando Meier, Scoping proposal	Unpublished
Armando Meier, University of Basel, Total Project Budget	Unpublished
GiveWell, "GiveWell's Impact"	Source
GiveWell, "Vitamin A Supplementation"	Source

• 1

  Armando Meier, Scoping proposal (unpublished)

• 2

  See the breakdown of our funds directed in 2024 here. 14% of GiveWell's total funds directed went to Vitamin A supplementation, and 3% to other nutrition programs.

• 3

  “The main studies we rely on were primarily conducted in the 1980s and 1990s, when the infectious disease landscape was different and child health was significantly worse than today. It’s likely that VAS delivered today would result in a significantly smaller reduction in mortality. We attempt to account for this with a -41% to -79% adjustment, but we’re uncertain about this for a number of reasons:”
  GiveWell, Vitamin A Supplementation, 2024

• 4

  Armando Meier, University of Basel, Total Project Budget (unpublished)

• 5

  Armando Meier, Scoping proposal (unpublished)

• 6

  See GiveWell's intervention report on VAS.