. 2014 Aug 1;24(8):1195–1209. doi: 10.1089/thy.2014.0052

Table 5.

Intervention Studies Investigating the Effect of Iodine Supplementation on Tg in Newborns, Children, and Adults

Authors	Age (years)^a; country	Study design^b	UIC (μg/L)^c				Tg (μg/L)^c				Findings	Comments
Newborns
Pedersen et al. (85)	Newborns; Denmark	Data obtained from infants (n=54) born to mothers who were randomized to receive either 200 μg I/day or no iodine supplement	0 μg		27		0 μg			67	Infants of mothers supplemented with 200 μg I/day had a significantly lower Tg than infants born to mothers not taking supplements (p=0.005)	A lag period (i.e., 5 days) between the collection of urine from infants and cord blood samples
			200 μg		64		200 μg			38
Glinoer et al. (86)	Newborns; Belgium	Data obtained from infants (n=180) born to mothers who were randomized to receive either 131 μg I/day, 131 μg+100 μg L-T4, or placebo	0 μg		43^d		0 μg			113^d	Infants of mother supplemented with 131 μg I and 131 μg I+L-T4 had a significantly lower Tg than infants of mothers taking placebo (p<0.001)	Cord blood used
			131 μg		77^d		131 μg			65^d
			131 μg+L-T4		80^d		131 μg+L-T4			52^d
Children
Benmiloud et al. (89)	6–11; Algeria	Children (n=169) randomized to receive either a single dose of iodized poppy seed oil orally (120, 240, 480, or 960 mg I) or intramuscular injection of 480 mg I for 150–395 days		Baseline	5 months		Baseline	5 months			All groups of children had a decrease in Tg after 5 months	The study only reported Tg values for baseline and 5 months
			Orally
			120 mg	27	41		98.5	31.0
			240 mg	25	99		98.5	22.0
			480 mg	25	109		175.0	24.0
			960 mg	25	132		77.0	14.0
			Injection
			480 mg	27	1185		62.0	12.0
Zimmermann et al. (47)	6–15; Morocco	Children (n=377) received IS for 12 months		Baseline	Months		Baseline	Months			Children had a significantly lower Tg after using IS for 12 months (p<0.001)
					5	12		5	12
				17	181	165	24.5	6.2	4.4
Zimmermann et al. (40)	5–14; Morocco	Children (n=86) received IS for 10 months		Baseline	Months		Baseline	Months			Children had a significantly lower Tg after using IS for 10 months (p<0.001)
					5	10		5	10
				12	74	102	49.0	13.0	8.0
Gordon et al. (64)	10–13; New Zealand	Children (n=184) randomized to receive either placebo or 150 μg I tablet daily for 28 weeks		Baseline	7 months		Baseline	7 months			Children taking iodine tablets had a significantly lower Tg after 7 months (p<0.001)	Main outcome was cognition
			0 μg	62	81		15.2	11.6
			150 μg	66	145		16.5	8.5
Adults
Thomson et al. (63)	60–80; New Zealand	Adults (n=100) randomized to receive either placebo, 100 μg Se, 80 μg I, or 100 μg Se+80 μg I daily for 12 weeks		Baseline^e	3 months^e		Baseline^e	3 months^e			Both groups taking iodine supplements had a significantly lower Tg after 3 months compared to baseline (p<0.01)
			0 μg	49	44		14.4	14.0
			Se	45	44		15.4	15.2
			80 μg	33	71		21.2	15.4
			Se+80 μg	63	84		17.3	14.7
Soriguer et al. (92)	34.9; Spain	A cross-over study of adults (n=30) randomized to 100, 200, or 300 μg I/day		Baseline^d,f	2 months^d,f		Baseline^d	2 months^d			There was no difference in Tg between the groups after supplementation	A cross-over study with 1 month washout; adults recruited were regular users of IS
			100 μg	192	233		3.9	0.8
			200 μg	140	230		7.6	8.8
			300 μg	201	377		6.8	4.0

^{^a}

Range used unless mean reported.

^{^b}

Only subjects with no known thyroid disease or negative for TgAb.

^{^c}

Median used unless mean or geometric mean reported.

^{^d}

Mean.

^{^e}

Geometric mean.

^{^f}

UIC reported as urinary iodine excretion (μg/day).

Se, selenium.