Iodine content of food groups

The iodine content of several kinds of foods representing different product groups available on the Swiss market was analyzed by isotope dilution inductively coupled plasma mass spectrometry using the enriched long-lived nuclide 129I. Considerable variations in levels of iodine between single foodstuffs within food groups were found, which also applied for levels in different food groups. The contribution of the food groups to the average daily iodine intake for the Swiss population was estimated from recent food consumption data. Bread and milk were identified as significant sources of iodine in the Swiss diet as they contributed 58 and 29 μg/day, respectively. The estimated contribution of all basic food groups to the per capita intake of iodine was approximately 140 μg/day, which was somewhat below the amount recognized for adequate nutrition (150 μg/day). In view of the additional consumption of iodized kitchen salt, an average of 140 μg/day underestimates the actual iodine intake.