In low-iodine counties, the probability of assignment to the Air Forces rose significantly after the introduction of iodized salt.

Evidence

The Cognitive Effects of Micronutrient Deficiency: Evidence from Salt Iodization in the United States (NBER)

Categorization

  • corroborated: 2 independent passages support this claim
  • XREF: connects to: Adding iodine to salt closed a 15-point IQ gap cheaply — Harriet A. Washington, A Terrible Thing to Waste, 18