Table 2.

The effect of iodised salt, iodine-containing multivitamin use, and smoking on the iodine status during pregnancy and lactation (n = 100). Data shown as median (interquartile range).

	Pregnancy		Lactation
	UIC (µg/L)	UIC (µg/g creatinine)	UIC (µg/L)	UIC (µg/g creatinine)	MIC (µg/L)a
Iodine supplementation
None	40 (15–84)	36 (24–64)	43 (31–61)	47 (32–88)	157 (92–227)
Only iodised salt	72 (25–118)	49 (35–90)	50 (32–90)	62 (43–91)	213 (134–261)
≥150 µg iodine/day	75 (38–111)	77 (42–126)b	62 (37–81)	79 (53–93)	236 (208–304)c
P valued	0.071	<0.005	0.344	0.121	<0.001
Smoking
Non-smokers	74 (36–112)	61 (36–126)	51 (31–80)	59 (40–91)	203 (119–280)
Smokers	40 (26–90)	48 (32–69)	47 (37–59)	52 (36–111)	150 (92–211)
P valuee	0.069	0.130	0.951	0.691	0.030

^an = 93; ^bPost hoc test results: significant difference compared to the subgroup of non-users, P < 0.005; ^cPost hoc test results: significant difference compared to the subgroup of non-users, P < 0.001. ^dKruskal–Wallis H test; ^eMann–Whitney U test.

MIC, milk iodine concentration; UIC, urinary iodine concentration.