BACKGROUND: Oral iodized poppy seed oil is an appropriate measure for 
controlling iodine deficiency in areas where iodized salt is not yet available. 
However, a more effective and cheaper iodized oil preparation is needed.
OBJECTIVE: The aim of this study was to compare the efficacy of iodized peanut 
oil with that of iodized poppy seed oil.
DESIGN: Schoolchildren aged 8-10 y were supplemented with a single oral dose of 
iodized peanut oil (P200, P400, or P800 mg I), iodized poppy seed oil (PS400 mg 
I), or peanut oil (placebo). The concentration of urinary iodine (UI) was 
measured at 0, 4, 12, 25, and 50 wk, whereas thyroid volume and serum 
thyrotropin and free thyroxine concentrations were measured at 0, 25, and 50 wk.
RESULTS: UI was higher in all treatment groups than in the placebo group, except 
at baseline. UI in the P200 group was not significantly different from that in 
the PS400 group at all times of measurement. In a comparison of preparations 
supplying 400 mg I conducted by using a mathematical model, iodine retention 
from the peanut oil preparation was 3 times that from the poppy seed oil, and 
the protection period for peanut oil was twice as long as that for the poppy 
seed oil (P < 0.001 for both). The reduction in thyroid volume was greater in 
the treatment groups than in the placebo group (P < 0.001). No significant 
differences in serum hormone concentrations were observed between groups before 
or after treatment.
CONCLUSION: Iodized peanut oil is more efficacious in controlling iodine 
deficiency than is iodized poppy seed oil containing the same amount of iodine.