Endocrine Abstracts

Introduction: Iodine is essential for thyroid funciton and severe deficiency adversely affects the developing brain. A raised and sufficient intake is particularly important during the pregnancy. Iodine sources include sea foods and sea salt, and it is available as a dietary supplement. The former was previously important to the Faroses diet but the intake of traditional Faroses foods is decreasing with at likely parallel influence on the iodine intake. Currently, there is no knowledge about the iodine status of pregnant women in the Faroe Islands. We thus aimed to determine the iodine intake among pregnant Faroese women.

Method: From June 2020 through April 2022, 672 eligible women were enrolled in early pregnancy, and 647 donated a morning spot urine sample and answered two questionnaires: one that pertained to demographic information and an iodine-specific questionnaire. Iodine concentration in urine (UIC) was determined using the Sandell-Kolthoff reaction modified according to Wilson and van Zyl.

Results: The participation rate was 63%. Median UIC was 110 µg/l (IQR 76 µg/l – 176 µg/l), and 43% had UIC <100 µg/l. Factors important for UIC <100 µg/l and <150 µg/l included age, intake of iodine containing vitamins or supplements within 48 hours, fish dinner, eggs, and the previous week’s fish cold-cut (OR, 0.3 – 0.9; P-values, 0.09 – <0.001). Cheese, milk products, seabirds and higher educational levels were positively associated with iodine nutrition among pregnant Faroese women. Gestational age, smoking, alcohol intake, BMI, and place of living did not associate with iodine intake levels. UIC decreased during data collection from a median UIC of 117 µg/l (IQR (84-183 µg/l) in June–November 2020, to 101 µg/l (IQR 68-143 µg/l) in December 2021–April 2022 (P = 0.004).

Conclusion: Overall, Faroese pregnant women were iodine depleted with 43% having an UIC <100 µg/l. However, the majority of those with UIC in the lower range were younger women, and the iodine nutrition had a distinctly decreasing trend coforming to the ongoing changes in dietary habits among younger women who tend to consume less iodine-rich foods. Hence, we recommend continuous monitoring of the iodine intake in pregnant women.