Determination of urinary iodine and creatinine concentration
Urinary iodine concentration was assessed spectrophotometrically, using a modification of the Sandell–Kolthoff reaction, with an initial ammonium persulfate digestion [Urinary creatinine, measured by the kinetic Jaffé reaction [The researcher who performed the urinary measurements was not aware of which group within the iMC Salt trial the participant was allocated to.