Iodine nutritional status of lactating women in northern Taiwan in 2019.

BACKGROUND Pregnant and lactating women are vulnerable to iodine deficiency. This study was conducted to evaluate the iodine nutritional status of lactating women in northern Taiwan. METHODS Women recruited from Taipei Veterans General Hospital (TVGH) in 2019 provided a spot urine sample and completed a food frequency questionnaire. The urinary iodine concentration (UIC) was measured by inductively coupled plasma mass-spectrometry. RESULTS The overall median UIC in 198 women was 120.4 μg/L, indicating a sufficient iodine status. Univariate analysis revealed a lower median UIC in women of younger age (p = 0.004), who were not taking multivitamins (p = 0.004), not on a post-partum nourishment diet (p = 0.04), and whose infant received more breast milk (p = 0.004). The median UIC was 50% breast milk (UIC: 86.1 μg/L). A post-partum nourishment diet was followed by 73.7% (n = 146) of the women. Nevertheless, a significant decrease in the intake frequency of iodine-containing foods, including seaweeds (p 50% breast milk vs. < 50% breast milk; OR: 2.93; 95% CI: 1.37-6.25) were independently associated with UIC < 100 μg/L. CONCLUSION The results suggest that the iodine status in lactating women in northern Taiwan is adequate. However, iodine deficiency may continue to be present in certain subgroups, such as women of younger age and those who do not take multivitamins.