Methods
The population study covered 103 adults within the iMC Salt randomized clinical trial, aged 24–69 years. Urinary iodine concentration was measured spectrophotometrically using the Sandell–Kolthoff reaction. Iodine food intake was assessed using a 24-h dietary recall. The contribution of discretionary salt to the iodine daily intake was assessed through 24-h urinary sodium excretion (UIE) and potentiometric iodine determination of household salt.