Table 1.

Basic information of subjects in four provinces.

Type	Indicators	Classification	Number	Proportion (%)
Pregnant Women (n = 2,145)	Habitation	Village	353	30.30
		Urban	812	69.70
	Gestation	First trimester	380	17.72
		Middle trimester	1,024	47.74
		Last trimester	741	34.54
	Degree of education	Primary/junior high school	478	41.07
		Senior high school/junior college	531	45.62
		Bachelor degree or above	155	13.31
	Pregnancy Vomiting reaction	No	727	34.41
		Slight	942	44.58
		Moderate	297	14.06
		Severe	147	6.95
	Dietary habit	Three meals a day	1,564	73.98
		Four meals a day	283	13.39
		Five or six meals a day	177	8.37
		Rule-less	90	4.26
	Drinking water type	Tap water	1302	61.47
		Others	816	38.53
	hypertension	Yes	11	1.17
		No	932	98.83
Adults (n = 1,660)	Gender	Male	759	45.72
		Female	901	54.28
	Labor intensity	Light manual labor	809	52.70
		Medium manual labor	553	36.03
		Heavy manual labor	173	11.27
	Drinking water type	Tap water	1,297	83.19
		Others	262	16.81
	hypertension	Yes	260	15.69
		No	1397	84.31

^aMUIC, median urinary iodine concentration.

^bMConsumption rate, the number of subjects receiving qualified iodized salt (iodine preparations or iodine-rich food) / the total number of subjects surveyed.

^cIodine supplement rate, the proportion of subjects who take iodized salt, iodine supplement preparations or iodine-rich foods.

^dQualified iodized salt, salt samples with iodine of 18-33mg/kg.