Iodine status from childhood to adulthood in females living in North-East Italy: Iodine deficiency is still an issue

This survey aimed to assess iodine status in a female population at different ages, also investigating their eating habits.

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.

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.

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.