New model for describing urinary iodine excretion: its use for comparing different oral preparations of iodized oil

Iodine excretion in urine after oral dosing with iodized oil is influenced by various factors involved in the retention and elimination of iodine by the body. In a study comparing different treatments of severely iodine-deficient schoolchildren from Malawi, a hyperbolic function was found to describe changes in urinary iodine concentration over time more adequately than a simple exponential function. Compared with oil A, comprising ethyl esters of iodized fatty acids, the retention and elimination of iodine from oil B, comprising triacylglycerol esters of iodized fatty acids, were significantly greater. The mean duration of effectiveness of oral iodized oil, based on urinary iodine concentrations > 0.40 mumol/L, was estimated to be 13.7, 9.9, and 52.5 wk for a single dose of iodized oil A (490 mg I), a split dose of iodized oil A (2 x 245 mg I), and a single dose of iodized oil B (675 mg I), respectively. Dividing the dose of oil A into two equal amounts given on consecutive days did not improve its efficacy.