Iodine Contents in Baby Food Consumed in Japan

To evaluate iodine intake in Japanese infants, iodine contents were determined in both commercial and homemade baby food samples consumed in Japan. Fifty-three samples of commercial bottled or retort baby food and 25 samples of homemade baby food for one day were collected and their iodine contents were determined by inductively coupled plasma mass spectrometry after an extraction with 0.5% tetramethylammonium hydroxide. Among the commercial baby food samples, 35 samples showed low iodine values (< 50 ng/g wet weight), while 8 samples showed markedly high iodine values (> 1000 ng/g wet weight). Significantly higher iodine values were observed in 15 samples composed of dishes cooked using kombu (a kind of kelp) than other samples. Among the homemade baby food samples, 12 samples brought very low iodine intake (< 1- 24 μg/d), while 5 samples brought very high iodine intake (283-978 μg/d). These results indicate that intermittent high iodine baby food including dishes cooked using kombu contributes to sufficient iodine intake in Japanese infants.