Purpose: This survey aimed to assess iodine status in a female population at different ages, also investigating their eating habits.
Methods: We measured urinary iodine concentrations (UIC) in: 634 females at puberty and 361 fertile women in 246 of whom were considered also their children (134 daughters and 120 sons). All subjects completed a food frequency questionnaire.
Results: Median UIC decreased from childhood to adulthood (median UIC 107, 77 and 55 μg/l in the young girls, females at puberty and fertile women, respectively). Though using iodized salt improved iodine status in all groups, a significantly higher UIC was only noted in females at puberty. Milk consumption significantly increased UIC at all ages. In mother-child (both daughters and sons) pairs, the children's median UIC was nearly twice as high as their mothers' (UIC 115 vs. 57 μg/l). Milk consumption varied significantly: 56% of the mothers and 76% of their children drank milk regularly. The children (both daughters and sons) and mothers who drank milk had UIC ≥100 μg/l in 59 and 34% of cases, respectively, among the pairs who did not drink milk, 44% of the children and 19% of the mothers had UIC ≥100 μg/l. On statistical regression, 3.6% of the variability in the children's UIC depended on that of their mothers.
Conclusions: Dietary iodine status declines from childhood to adulthood in females due to different eating habits. A mild iodine deficiency emerged in women of child-bearing age that could have consequences during pregnancy and lactation.
Keywords: Childhood; Iodine; Iodized salt; Milk; Pregnancy.