You’ve likely used iodized salt without thinking about it. That small adjustment, adding iodine to a common ingredient, is one of the most widespread nutrition strategies in the world.
New research suggests it is also one of the most effective.
A modeling study published in The Lancet Global Health estimates that fortifying staple foods like salt, flour, rice and oil prevents about 7 billion instances of inadequate nutrient intake globally each year. Researchers say improving and expanding these programs could increase that impact to 25 billion nutrient gaps prevented annually, at a cost of about $1.15 per person.
The study was conducted by researchers affiliated with the Global Alliance for Improved Nutrition along with collaborators from the World Bank, Tufts University and the University of California.
Researchers analyzed dietary intake data alongside fortification program data across 185 countries, covering more than 99% of the global population. They evaluated 13 micronutrients, including iron, iodine and vitamin A, across commonly fortified foods such as wheat flour, maize flour, rice, oil and salt.
Instead of measuring direct health outcomes, the study modeled “nutrient gaps,” or instances where people do not get enough of a specific nutrient. That could mean one person lacking multiple nutrients or multiple people each lacking one. As a result, the findings reflect estimated population-level impact rather than observed clinical outcomes.
“This research confirms that food fortification is one of the most cost-effective public health interventions available,” said Dr. Mduduzi Mbuya, director of knowledge leadership at GAIN and a co-author of the study.
Despite current programs, researchers estimate that 38.6 billion nutrient gaps still exist globally, driven by factors such as limited access to nutritious foods, inconsistent fortification standards and low compliance in some regions.
The analysis also identified opportunities to expand impact. Improving compliance with existing fortification standards to 90% could prevent an additional 6.1 billion nutrient gaps annually.
“Improving compliance with current laws could prevent 6.1 billion more nutrient gaps at an additional cost of only $0.05 a person,” said Dr. Christopher Free, a research professor at the University of California, Santa Barbara and joint first author of the study.
Researchers estimate current fortification programs cost about $0.18 per person annually, while expanded programs could reach about $1.15 per person. The study also estimates that each dollar invested in fortification yields about $27 in economic returns through improved health and productivity, though those projections are based on modeled assumptions.
“Fortification is a powerful tool, but it is most effective as part of a comprehensive strategy,” said Florencia Vasta, global lead for large-scale food fortification at GAIN.
Experts note that while fortification can help reduce widespread nutrient deficiencies, it does not replace the need for broader dietary improvements. Increasing access to diverse foods and targeted supplementation for vulnerable groups, such as pregnant women and young children, remain important components of improving nutrition globally.
The study was funded by the Swiss Agency for Development and Cooperation and the Gates Foundation.