Table 4.
Biomarker iodine concentrations in gestational week 29 (GW29) and at 4 months postpartum (4M) grouped by the use of iodized table salt.
| Biomarker | n | Non-iodized table salt and/or non-table salt1 (n = 65) | n | Mix of iodized table salt and other (n = 141) | n | Solely iodized table salt (n = 247) | p |
|---|---|---|---|---|---|---|---|
| Median (25−75th) | Median (25−75th) | Median (25–75th) | |||||
| IODINE | |||||||
| Maternal urine, μg/L (GW29)2 | 63 | 106 (74–134)a | 138 | 113 (81–175) | 242 | 117 (83–176)a | 0.095 |
| Breast milk, μg/kg (4M) | 37 | 53 (40–117) | 90 | 73 (50–115) | 154 | 78 (54–119) | 0.245 |
| Infant urine, μg/L (4M)3 | 44 | 102 (58–146) | 85 | 115 (92–145) | 170 | 115 (81–155) | 0.221 |
| Breastfed | 28 | 85 (51–144)a | 53 | 114 (85–142) | 108 | 115 (80–171)a | 0.074 |
| Not breastfed4 | 16 | 117 (85–161) | 32 | 117 (95–153) | 62 | 114 (87–137) | 0.739 |
Differences between salt groups were tested with Kruskal-Wallis test and presented with p-values. Test between two groups per time was made with Mann-Whitney U test and significant differences between groups are presented with matching letters in superscript.
Non-Table Salt includes use of Flake Salt/Coarse sea Salt, Rock Salt (e.g., Himalayan Salt), Mineral Salt (low in Sodium e.g., Seltin) or Other Salt.
Adjusted to the mothers mean urinary specific gravity (SGmean = 1.017).
Adjusted to the infants mean urinary specific gravity (SGmean = 1.004).
Estimated based on available breast milk sample at 4 months or not, regardless of reported extent.