Knowledge · Natural Compounds

Iodine

Q: Does Iodine help with children and growth? What the studies show

We evaluated 7 meta-analyses or systematic reviews, 19 controlled studies and 20 further studies; the controlled studies include 5,551 participants in total. Result of the controlled studies: mostly no difference. Strength of evidence under our published rules: high. Sources: [1, 2, 3, 4]

Q: Does Iodine help with goitre (struma)? What the studies show

We evaluated one meta-analysis or systematic review, 8 controlled studies and 9 further studies; the controlled studies include 6,386 participants in total. Result of the controlled studies: mixed. Strength of evidence under our published rules: high. Sources: [5, 8, 12, 58]

Q: Does Iodine help with iodised salt and fortification programmes? What the studies show

We evaluated one meta-analysis or systematic review, 5 controlled studies and 10 further studies; the controlled studies include 2,556 participants in total. Result of the controlled studies: mixed. Strength of evidence under our published rules: low. Sources: [23, 30, 34, 41]

Q: What is iodine studied for in human studies?

The main areas investigated are the correction of iodine deficiency, thyroid volume and the frequency of goitre. In iodine deficiency areas, controlled studies showed that iodine administration had advantages for iodine status, thyroid volume and frequency of goitre [8, 70, 88, 94]. In addition, iodine status, thyroid hormone levels and urinary iodine excretion were measured as supply and laboratory parameters.

Q: Which iodine forms were tested in the studies?

Predominantly potassium iodide, potassium iodate, iodised table salt and iodised oil were tested, and in some cases also molecular iodine. The forms differ in absorption and effect, so findings apply only to the respective form and preparation investigated. Algae and kelp preparations have a fluctuating iodine content and were not tested as pure iodine.

Q: Does iodine show a benefit when supply is adequate?

That is still open: in a study with breastfeeding mothers in a country with salt iodisation, the infants' urinary iodine excretion remained the same under the lower iodine dose as under placebo [82]. The demonstrated benefit mainly concerns correcting an existing iodine deficiency.

Q: How well tolerated was iodine in the studies?

In studies on iodine administration in iodine-deficient areas, predominantly no or only mild, temporary side effects were reported [8, 63, 65, 66]. In a controlled study with iodide tablets in pregnant women, adverse events occurred with similar frequency in both groups [35].

Q: What should be noted with algae and kelp preparations?

Algae and kelp preparations have a fluctuating iodine content and were not tested as pure iodine.

Iodine is an essential trace element; human studies show benefits mainly in correcting an iodine deficiency, for example for the thyroid gland and goitre.

Last updated: 2026-10-15

We evaluated 155 human studies on Iodine, including 63 randomised controlled trials and 26 meta-analyses or systematic reviews; the controlled studies include 24,647 participants in total. As of 14 October 2026.

This page as PDF · Summary

1. What Is Iodine? Occurrence, Origin and Forms

Iodine is a halogen and an essential trace element that the body cannot produce itself. It occurs in seaweed, marine fish and iodised table salt, and in the thyroid gland it is a building block of thyroid hormones. Traditionally it is used to prevent iodine deficiency and goitre.

Iodine occurs in seaweed, marine fish, seafood and iodised table salt; in soils and drinking water its distribution varies greatly by region. It is studied as a dietary supplement, as iodised salt and in fortified foods.

Industrially, iodine is obtained from iodine-containing brines and salt deposits, and partly from seaweed. Studies mainly examine potassium iodide, potassium iodate, sodium iodide and molecular iodine, either alone or in fortified foods.

Forms and Preparations Studied

Potassium iodide
Potassium iodate
Sodium iodide
Molecular iodine (I₂)
Iodised table salt
Seaweed and kelp preparations

Not covered on this page:

Radioiodine (I-131) in thyroid diagnostics and therapy
Iodine-containing skin antiseptics
Thyroid hormone preparations such as levothyroxine
Iodinated X-ray contrast media and iodine-containing drugs such as amiodarone

2. What Does Iodine Do? Results by Area

Area	Result in controlled studies	Strength of evidence	Studies	Participants
Children and growth	mostly no difference	high	7 meta-analyses · 19 controlled · 20 other	5,551
Goitre (struma)	mixed	high	1 meta-analyses · 8 controlled · 9 other	6,386
Iodised salt and fortification programmes	mixed	low	1 meta-analyses · 5 controlled · 10 other	2,556
Other investigations	mixed	high	14 meta-analyses · 55 controlled · 50 other	20,233

How to read the table: counted are human studies whose results concern the area. “High” means at least one meta-analysis and two controlled studies showing improvement, or at least three controlled studies of which three quarters show improvement, with at least 300 participants in total. “Moderate” means at least two controlled studies showing improvement, as a majority, or one meta-analysis alongside controlled studies. “Low” means one controlled study showing improvement. Where an area has no controlled study, the strength of evidence is at most “low” (result “reviews only” or “observational data only”). Everything else is “unclear”. A study counts as showing improvement when at least half of its outcomes in this area improved. Reviews of combination products do not count as meta-analyses; results that only describe side effects or shares of users do not count as an effect. The same study is counted only once.

3. What the Studies Show in Detail

Iodine, Children and Growth: Human Studies

In regions with iodine deficiency, iodised table salt was associated with better cognitive development of the children in a randomised study in Ethiopia, growth did not differ 29 30. In children with mild iodine deficiency, a controlled study with iodide tablets found better scores in individual cognitive subtests 48, while another controlled study with iodide tablets in pregnant women with mild iodine deficiency saw no difference in the children's IQ 35. The findings apply to iodised table salt, iodide tablets and iodised oil. Combined preparations with other micronutrients cannot be attributed to iodine alone 1 3. Urinary iodine excretion is a supply parameter, not a clinical effect. Thyroid values are laboratory values, not a clinical effect. Overall, the findings are inconsistent: a benefit is seen mainly in correcting an existing iodine deficiency, not with additional administration to adequately supplied children.

Study	Design · participants	Preparation · dose · duration · comparison	Result
1 Keats et al. 2021	systematic review · 451,723 participants	Single and multiple micronutrient supplements, including iodine; Pregnancy; vs. Folic acid, iron-folic acid, multiple micronutrients, lipid-based nutrients	Low birthweight (IFA vs. folic acid): improved (average RR 0.88, 95% CI 0.78 to 0.99); Low birthweight (MMN vs. iron ± folic acid): improved (average RR 0.85, 95% CI 0.77 to 0.93)
2 Levie et al. 2019	meta-analysis · 6,180 participants	No supplement; urinary iodine and creatinine measured in pregnancy; Pregnancy, gestational weeks up to 14 relevant; vs. UI/Creat <150 µg/g versus higher values	Child verbal IQ: no difference (-0.6 point; 95% CI: -1.3 to 0.1 points; P = 0.082); Child nonverbal IQ: no difference (-0.6 point; 95% CI: -1.7 to 0.4 points; P = 0.246)
3 Farebrother et al. 2018	systematic review · 5,729 participants	Iodine fortification (iodized salt) or iodine supplements, any form/dose; any dose and regimen, not reported individually; vs. Placebo, noniodized salt, or no intervention	Mean birthweight in severe iodine deficiency: improved (MD: 200 g; 95% CI: 183, 217 g); Primary growth outcomes in other groups: no difference; Insulin-like growth factor-1 in moderate-to-mildly iodine-deficient schoolchildren: improved (MD: 38.48 ng/mL; 95% CI: 6.19, 70.76 ng/mL)
4 Harding et al. 2017	systematic review · 2,700 participants	Iodine tablets, capsules or drops, sometimes with vitamins/minerals; vs. no iodine supplementation	Perinatal mortality: improved (average RR 0.)
5 Velasco et al. 2026	systematic review · 2,528 participants	Iodine supplementation alone or with iron; 150 µg daily for 28 weeks; single dose 100 mg or 400-490 mg; Follow-up 3 to 22 months; vs. Placebo	Cognitive function (validated scales): improved (standardised mean difference 0.19, 95% confidence interval (CI) 0.04 to 0.34); Weight (kg): no difference (mean difference (MD) -0.20, 95% CI -1.92 to 1.52)
7 Walsh et al. 2019	systematic review · 1,394 participants	Iodine as iodide salt added to enteral or parenteral feeds; vs. Placebo or no supplementation	Mortality before hospital discharge: no difference (typical RR 1.01, 95% CI 0.72 to 1.42); Bayley-III cognitive composite score at 2 years: no difference (MD -0.30, 95% CI -2.44 to 1.84); Bayley-III motor composite score at 2 years: no difference (MD 0.20, 95% CI -2.15 to 2.55)
16 Daniel et al. 2025	systematic review	No iodine intervention, observation of iodine status (diet, iodized salt); Studies 2010 to 2024, NHANES data 2011-2020; vs. No intervention control; WHO threshold <150 µg/L	Offspring neurodevelopment and IQ with low maternal UIC: worsened (reduced IQ scores)
21 Favara et al. 2024	systematic review	Iodine via maternal diet/supplements	Neurodevelopment: improved

Further studies in this area: 23 24 25 29 30 35 37 43 44 45 47 48 53 58 61 62 68 70 82 85 88 93 96 97 104 105 113 114 117 121 122 127 131 139 144 145 146 147

Iodine and Goitre (Struma): Human Studies

In iodine deficiency areas, daily iodine administration in pregnant women slowed the increase in thyroid volume compared with controls 70 88. After birth, the volume fell compared with the baseline value 65 66. A placebo-controlled study found no confirmed difference in thyroid volume 63. The frequency of goitre fell in Zaire in villages with iodised oil, whether given by mouth or as an injection, while it remained the same in control villages 94. A Cochrane review found a trend towards less goitre with iodised table salt, not significant in all studies 8. In breastfeeding women, the frequency of goitre fell with potassium iodide capsules or iodised salt compared with the baseline value 58. The findings apply to people with existing iodine deficiency; whether additional iodine administration is beneficial when supply is sufficient is therefore not clarified. Algae and kelp preparations as well as multi-ingredient preparations with fluctuating iodine content were not tested as pure iodine and do not allow conclusions of their own.

Study	Design · participants	Preparation · dose · duration · comparison	Result
5 Velasco et al. 2026	systematic review · 2,528 participants	Iodine supplementation alone or with iron; 150 µg daily for 28 weeks; single dose 100 mg or 400-490 mg; Follow-up 3 to 22 months; vs. Placebo	Goitre: unclear (RR 0.68, 95% CI 0.15 to 3.07)
8 Wu et al. 2002	systematic review · 334 participants	Iodised salt; vs. Non-iodised salt, iodised water, iodised oil, potassium iodide vs. potassium iodate	Goitre rate: improved
12 Harikrishnan et al. 2026	systematic review	Iodine via diet/iodized salt (regions with differing iodine status); vs. Coastal versus inland regions	Prevalence of goiter: improved
58 Gebreegziabher et al. 2019	randomised controlled · 106 participants	Potassium iodide capsule vs. iodized salt; 225 µg iodine daily as capsule or iodized salt weekly; 26 weeks; vs. Potassium iodide capsule vs. iodized salt	Goiter prevalence: unclear (significantly decreased)
63 Censi et al. 2019	randomised controlled · 90 participants	potassium iodide tablets (iodide) versus placebo; 225 µg/day; from enrollment until 8 weeks after delivery; vs. placebo control group (3:2 randomization)	thyroid volume (TV): no difference (+Δ7.43% in the Iodine group, and by +Δ11.17% in the Placebo group)
65 Reinhardt et al. 1998	randomised controlled · 70 participants	potassium iodide; 50 µg or 250 µg daily; 8 months postpartum, starting 5 days after delivery; vs. 50 µg versus 250 µg; plus untreated group in study I	thyroid volume: unclear (25.4 +/- 1.5 ml (mean +/- sem) to 18.2 +/- 1.25 p <0.001); thyroid volume without iodine: unclear (29 +/- 2.2 ml; at 3 months 27.5 +/- 3.0 ml)
66 Antonangeli et al. 2002	randomised controlled · 67 participants	iodide (potassium iodide) daily; 200 µg/day (group A) vs. 50 µg/day (group B); daily up to 6 months after delivery; vs. 200 µg iodide vs. 50 µg iodide daily	thyroid volume during gestation: unclear (slight but not significant increase in TV during gestation was observed only in group B); thyroid volume after delivery: unclear (final TV being significantly reduced with respect to the initial volume in group A)
70 Pedersen et al. 1993	randomised controlled · 54 participants	iodine supplementation; 200 µg iodine/day; from weeks 17-18 of pregnancy until 12 months after delivery; vs. control group without iodine	thyroid size: improved

Further studies in this area: 88 89 94 99 111 112 113 127 135 144

Iodine, Iodised Salt and Fortification Programmes: Human Studies

In regions with iodine deficiency, iodised table salt improved iodine status: a randomised controlled study with over a thousand pregnant women and their children in Ethiopia found less iodine deficiency in mothers and children 30. Another randomised study in Ethiopia advised mothers on the use of iodised salt and found a higher urinary iodine excretion in the children of the intervention group than in the control group 34. Both studies took place in regions with existing iodine deficiency, not with adequate supply. With mixtures, the attribution to iodine alone is limited: salt double-fortified with iodine and folic acid did not change salt intake 41, and a salt fortified four times with iron, iodine, folic acid and vitamin B12 did not differ from salt double-fortified with iron and iodine in acceptance, consumption and sensory distinguishability 64. The strength of evidence is low; the controlled studies are small to medium-sized and largely limited to Ethiopia, while the remaining work mainly describes supply and laboratory values such as urinary iodine excretion and some remained without a control group.

Study	Design · participants	Preparation · dose · duration · comparison	Result
23 Bath et al. 2022	systematic review	Iodine from iodized salt and foods; vs. Intake versus dietary recommendations	National surveys including iodized salt in estimation: unclear (32% of national surveys (n = 7))
30 Mohammed et al. 2020	randomised controlled · 1,220 participants	Iodized salt via early market access; from conception to child age 2–13 months; vs. control with later market access to iodized salt	Iodine deficiency (UIC <50 μg/L) in mothers prepartum: improved (28% vs. 41%, p < .05); Iodine deficiency (UIC <50 μg/L) in children: improved (13% vs. 20%, p < .05)
34 Ferede et al. 2026	randomised controlled · 834 participants	Iodized table salt (iodide) in households; mean iodide content 45.3 ppm in table salt; 15-month intervention; vs. intervention vs. control group (cluster randomized)	iodide content in table salt: unclear (45.3 ppm)
41 Nane et al. 2026	randomised controlled · 342 participants	Double-fortified salt with iodine and folic acid (DFS-IoFA); vs. Salt intake before versus during intervention	Discretionary salt intake: no difference (8.7 ± 4.3 g/d before and 8.8 ± 4.0 g/d during the intervention (P = 0.8))
64 Guetterman et al. 2025	randomised controlled · 77 participants	Quadruple-fortified salt (iron, iodine, folic acid, vitamin B12) vs. double-fortified salt vs. iodized salt; 3 weeks (1 week per salt type); vs. Double-fortified salt and iodized salt	Acceptability (overall hedonic rating): no difference (QFS: 7.8 (0.7) compared with DFS: 7.7 (1.2); P = 0.68); Weighed household salt use: no difference; Sensory discrimination in triangle tests: no difference
91 Pattisapu et al. 2024	controlled · 83 participants	Double fortified salt (folic acid plus iodine); approximately 300 µg/d folic acid; 4 months; vs. pre-post design, no control group	median serum folate: improved (increased from 14.6 (IQR, 11.2-20.6) nmol/L at baseline to 54.4 (IQR, 43.5-54.4) nmol/L)
95 Catumbela et al. 2025	cross-sectional study · 2,250 participants	Household iodized salt; Adequate iodization 15-40 ppm; vs. Pregnant vs. non-pregnant; provincial strata	Households using iodized salt: unclear (74.3%); Households with adequately iodized salt (15-40 ppm): unclear (29.2%)
96 Jamal¹ et al. 2026	cross-sectional study · 300 participants	Iodized salt (household use); vs. Children with above-average vs. below-average IQ	Maternal knowledge of iodized salt: improved

Further studies in this area: 99 111 113 114 117 128 140 146

Iodine: Further Outcomes in Studies

In iodine deficiency areas, iodised table salt raised urinary iodine excretion 8 29. With iodine administration, thyroglobulin was lower or rose less than in the control groups 48 54 55 63 70. The infants' urinary iodine excretion remained the same under the lower iodine dose given to the mother as under placebo 82, and potassium iodide capsules and iodised salt did not differ in breast milk and urinary iodine in breastfeeding women 85. Urinary iodine excretion fell in one study under a palaeolithic diet that excludes iodised table salt and dairy products, compared with a diet according to the Nordic recommendations 84. The robustness is inconsistent, because the studies examined very different forms — iodide, iodate, molecular iodine, iodised table salt, iodised oil and iodine-rich foods — in some cases small groups and often only over months. Some of the investigations concerned combined preparations with iron, folic acid, zinc or other micronutrients, whose findings cannot be attributed to iodine alone 1 9 10. It remains open how an additional iodine administration affects people who are already adequately supplied and whether the observed laboratory changes also have clinical consequences.

Study	Design · participants	Preparation · dose · duration · comparison	Result
1 Keats et al. 2021	systematic review · 451,723 participants	Single and multiple micronutrient supplements, including iodine; Pregnancy; vs. Folic acid, iron-folic acid, multiple micronutrients, lipid-based nutrients	Maternal anaemia (IFA vs. folic acid): improved (average risk ratio (RR) 0.52, 95% CI 0.41 to 0.66); Stillbirths (MMN vs. iron ± folic acid): improved (average RR 0.91; 95% CI 0.86)
4 Harding et al. 2017	systematic review · 2,700 participants	Iodine tablets, capsules or drops, sometimes with vitamins/minerals; vs. no iodine supplementation	Postpartum hyperthyroidism: improved (average risk ratio (RR) 0.32; 95% confidence interval (CI) 0.11 to 0.91); Digestive intolerance in pregnancy: worsened (average RR 15.33; 95% CI 2.07 to 113.70); Hypothyroidism in pregnancy: no difference (average RR 1.90; 95% CI 0.57 to 6.38)
5 Velasco et al. 2026	systematic review · 2,528 participants	Iodine supplementation alone or with iron; 150 µg daily for 28 weeks; single dose 100 mg or 400-490 mg; Follow-up 3 to 22 months; vs. Placebo	Hypothyroidism: improved (risk ratio (RR) 0.03, 95% CI 0.00 to 0.23); All-cause mortality in infants: improved (RR 0.32, 95% CI 0.14 to 0.73)
6 Haroon et al. 2026	meta-analysis · 2,257 participants	Preoperative iodine solution; vs. Control group without iodine solution	Intraoperative estimated blood loss: no difference (mean difference = -24.6 mL, 95% confidence interval: -56.2, 7.0); Operative time: no difference (mean difference = -2.3 minutes, 95% confidence interval: -10.6, 6.0); Endocrine-related complications: no difference (odds ratio = 0.85, 95% confidence interval: 0.42, 1.74)
8 Wu et al. 2002	systematic review · 334 participants	Iodised salt; vs. Non-iodised salt, iodised water, iodised oil, potassium iodide vs. potassium iodate	Urinary iodine excretion: improved
9 Abe et al. 2016	systematic review · 52 participants	Multiple-micronutrient supplement (three or more micronutrients); vs. Placebo or no supplementation	Maternal anaemia: improved
10 Lall et al. 2026	systematic review	Salt fortified with iodine and other nutrients; vs. Control groups without fortified salt	Hemoglobin concentration: improved (0.36 (0.22, 0.50)); Odds of anemia: improved; Odds of iron deficiency anemia: improved
11 Nazeri et al. 2026	systematic review	Iodized salt, iodine-containing supplements, iodized oil; vs. No uniform comparison; iodine status or supplementation vs. control	Postpartum depressive symptoms and anhedonia with low iodine intake: worsened; Effect of supplementation/fortification on maternal mood: unclear

Further studies in this area: 12 13 14 15 16 17 18 19 20 22 23 25 26 27 28 29 31 32 33 36 37 38 39 40 43 44 45 46 48 49 50 51 52 54 55 56 57 58 59 60 61 63 65 66 67 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 85 86 87 88 89 90 92 94 95 98 99 100 101 102 103 104 106 107 108 109 110 112 115 116 118 119 120 121 123 124 125 126 127 128 129 130 132 133 134 136 137 138 139 140 141 142 143 144 145 148 149

4. How Is Iodine Dosed? Preparation, Dose and Duration in Studies

The studies predominantly tested oral forms: potassium iodide tablets, potassium iodate, iodised table salt and iodised oil, and in some cases also molecular iodine. Some investigations gave iodine via fortified foods or as part of multinutrient preparations. Algae and kelp preparations have a fluctuating iodine content and were not tested as pure iodine.

Preparation or form	Dose	Duration	Study
Supplement with myo-inositol, probiotics and micronutrients incl. iodine	—	up to 12 months	27
MMN with 250 µg iodine or SQ-LNS with similar nutrient content	250 µg/d iodine (MMN); LNS similar; IFA: 60 mg Fe + 400 µg folic acid	until childbirth (UIC measured at week 36)	28
Iodized salt (early market access)	—	pregnancy until child age 2–13 months	29
Iodized salt via early market access	—	from conception to child age 2–13 months	30
Quintuply-fortified salt (QFS) with iodine, iron, zinc, vitamin B12, folic acid vs standard iodized salt	—	12 months	31
Quintuply-fortified salt (QFS) vs. iodized salt	Salt disappearance 6.0 g/adult female equivalent/day; iodine dose not reported	12 months (assessments at 0, 6 and 12 months)	32
Daily prenatal multiple micronutrient supplement containing iodine vs. iron and folic acid (FeFol)	300 µg iodine daily	Pregnancy until 30 weeks' gestation; follow-up to 24 weeks postpartum	33
Iodized table salt (iodide) in households	mean iodide content 45.3 ppm in table salt	15-month intervention	34
200 µg iodine orally once daily as a tablet until delivery vs. placebo	200 µg iodine once daily, adherence 87%	from enrolment (mean gestational age 10·7 weeks) to delivery; children re-assessed at age 5–6 years	35
Oral iodized oil (OIO) vs. poppy-seed oil placebo	—	First dose at 8 weeks, boosters at 4-week intervals, follow-up at 6 months	36
Daily oral iodine 200 µg or placebo until delivery	200 µg iodine daily orally	Until delivery, compliance 88%	37
Quintuply-fortified salt (QFS) vs. iodized salt (IS)	—	12 months	38
About 10 g iodized salt daily versus noniodized salt with low-iodine or noniodine diet	about 10 grams of iodized salt daily	dietary intervention 24 months; recurrence assessed 12 months after ATD withdrawal	39
Iodized salt with 32 ppm iodine, fortified with folic acid	7.8 ± 1.8 g salt/day; folic acid 99, 36 or 0 ppm	26 weeks, bi-weekly delivery	40
Iodized oil (iodine form/dose not reported); plus selenium or placebo	not reported	12 months	42

5. Is Iodine Safe? Side Effects in Studies

In the studies on iodine administration in iodine-deficient areas, predominantly no or only mild, temporary side effects were reported 8 63 65 66. In a controlled study with iodide tablets in pregnant women, adverse events occurred with similar frequency in both groups 35.

Study	Reported side effects
4 Harding et al. 2017	Less postpartum hyperthyroidism, more digestive intolerance in pregnancy
5 Velasco et al. 2026	No study reported adverse events related to iodine
6 Haroon et al. 2026	Endocrine complications, hypocalcemia, hematoma, recurrent laryngeal nerve injury similar to control
8 Wu et al. 2002	No adverse effects observed
9 Abe et al. 2016	none reported, no data on adverse effects
11 Nazeri et al. 2026	Potential increase in emotional distress under specific conditions (supplementation)
13 Lv et al. 2026	not reported
25 Zhou et al. 2013	Safety assessed, no specific findings reported
32 Goh et al. 2025	not reported
35 Gowachirapant et al. 2017	adverse events similar between groups: 24 vs. 28 women (abortion, blighted ovum, intrauterine death)
37 Verhagen et al. 2020	Slightly greater decrease in free and total thyroxine in the iodine group (p < 0.05)
40 Tessema et al. 2026	No group-wise differences in reported adverse events

6. What Remains Open: Limits of the Evidence

The benefit has been shown mainly for correcting an existing iodine deficiency; the effect of additional iodine administration when supply is adequate is open.
Many controlled studies are small to medium-sized and predominantly limited to individual regions such as Ethiopia.
The studies tested very different iodine forms and preparations, which makes direct comparison difficult.
Findings on combination preparations with other micronutrients cannot be attributed to iodine alone.
Whether observed changes in laboratory values such as urinary iodine excretion also have clinical consequences remains unclear.

7. Bottom Line: What Is Established About Iodine

Iodine is an essential trace element that the body cannot produce itself, and in the thyroid gland it is a building block of thyroid hormones. Human studies show the clearest benefit in correcting an existing iodine deficiency: in iodine-deficient areas, iodine administration dampened the increase in thyroid volume during pregnancy 70 88, and the frequency of goitre decreased in villages with iodised oil 94. Iodised table salt also improved the iodine status of mothers and children 30. In children in iodine-deficient regions, iodised table salt was associated with better cognitive development in a randomised study in Ethiopia, while no difference was found in growth 29 30.

The findings apply to the respective form and preparation investigated, especially iodide, iodate, iodised table salt and iodised oil. Algae and kelp preparations as well as multinutrient preparations with fluctuating iodine content do not allow conclusions of their own about pure iodine.

Frequently Asked Questions

How well has Iodine been studied in humans?

Does Iodine help with children and growth? What the studies show

We evaluated 7 meta-analyses or systematic reviews, 19 controlled studies and 20 further studies; the controlled studies include 5,551 participants in total. Result of the controlled studies: mostly no difference. Strength of evidence under our published rules: high. Sources: 1 2 3 4

Does Iodine help with goitre (struma)? What the studies show

We evaluated one meta-analysis or systematic review, 8 controlled studies and 9 further studies; the controlled studies include 6,386 participants in total. Result of the controlled studies: mixed. Strength of evidence under our published rules: high. Sources: 5 8 12 58

Does Iodine help with iodised salt and fortification programmes? What the studies show

We evaluated one meta-analysis or systematic review, 5 controlled studies and 10 further studies; the controlled studies include 2,556 participants in total. Result of the controlled studies: mixed. Strength of evidence under our published rules: low. Sources: 23 30 34 41

What is iodine studied for in human studies?

The main areas investigated are the correction of iodine deficiency, thyroid volume and the frequency of goitre. In iodine deficiency areas, controlled studies showed that iodine administration had advantages for iodine status, thyroid volume and frequency of goitre 8 70 88 94. In addition, iodine status, thyroid hormone levels and urinary iodine excretion were measured as supply and laboratory parameters.

Which iodine forms were tested in the studies?

Predominantly potassium iodide, potassium iodate, iodised table salt and iodised oil were tested, and in some cases also molecular iodine. The forms differ in absorption and effect, so findings apply only to the respective form and preparation investigated. Algae and kelp preparations have a fluctuating iodine content and were not tested as pure iodine.

Does iodine show a benefit when supply is adequate?

That is still open: in a study with breastfeeding mothers in a country with salt iodisation, the infants' urinary iodine excretion remained the same under the lower iodine dose as under placebo 82. The demonstrated benefit mainly concerns correcting an existing iodine deficiency.

How well tolerated was iodine in the studies?

In studies on iodine administration in iodine-deficient areas, predominantly no or only mild, temporary side effects were reported 8 63 65 66. In a controlled study with iodide tablets in pregnant women, adverse events occurred with similar frequency in both groups 35.

What should be noted with algae and kelp preparations?

Algae and kelp preparations have a fluctuating iodine content and were not tested as pure iodine.

Sources

1
Effects of vitamin and mineral supplementation during pregnancy on maternal, birth, child health and development outcomes in low- and middle-income countries: A systematic review
Keats EC, Oh C, Chau T, Khalifa DS, Imdad A, Bhutta ZA · 2021
2
Association of Maternal Iodine Status With Child IQ: A Meta-Analysis of Individual Participant Data
Levie D, Korevaar TIM, Bath SC, Murcia M, Dineva M, Llop S et al. · 2019
3
Effects of Iodized Salt and Iodine Supplements on Prenatal and Postnatal Growth: A Systematic Review
Farebrother J, Naude CE, Nicol L, Sang Z, Yang Z, Jooste PL et al. · 2018
4
Iodine supplementation for women during the preconception, pregnancy and postpartum period
Harding KB, Peña-Rosas JP, Webster AC, Yap CM, Payne BA, Ota E et al. · 2017
5
Iodine supplementation for preventing iodine deficiency disorders in children and adolescents
Velasco I, Rueda-Etxebarria M, Trak-Fellermeier MA, Taylor P, Rabassa Bonet M, Chi Y et al. · 2026
6
The effect of iodine solution in total thyroidectomy for patients with Graves disease: A meta-analysis
Haroon AM, Ghani A, Ayesh AR, Witkowiak MM, Alogakos M, Burns J et al. · 2026
7
Iodine supplementation for the prevention of mortality and adverse neurodevelopmental outcomes in preterm infants
Walsh V, Brown JVE, McGuire W · 2019
8
Iodised salt for preventing iodine deficiency disorders
Wu T, Liu GJ, Li P, Clar C · 2002
9
Supplementation with multiple micronutrients for breastfeeding women for improving outcomes for the mother and baby
Abe SK, Balogun OO, Ota E, Takahashi K, Mori R · 2016
10
The Effects of Salt Fortified with Multiple Nutrients on Health Outcomes in Children, Adolescents, and Adults: A Systematic Review and Meta-Analysis
Lall G, Zimmermann MB, Schultink W, Larson LM · 2026
11
Iodine Nutrition as a Potential Determinant of Maternal Depression During Pregnancy and the Postpartum Period: A Scoping Review
Nazeri P, Taghva Nakhjiri M, Chashmyazdan M, Pearce EN · 2026
12
Prevalence of thyroid disorders in inland and coastal populations: A systematic review
Harikrishnan ST, Azeez A, Reji S, Jacob DM, Al Hamdani MS, Eksheir S et al. · 2026
13
Effects of different iodine supplementation strategies on thyroid function in iodine-deficient pregnant women: a meta-analysis
Lv Y, Jin B, Guo J, Bu J, Chen C, Han Y et al. · 2026
14
Association of Mild-to-Moderate Iodine Deficiency With Thyroid Function-A Systematic Review and Meta-analysis
Aarsland TE, Aakre I, Stea TH, Henjum S, Markhus MW, Strand TA et al. · 2025
15
The myth of iodine: A systematic review and meta-analysis on the relationship between iodine and thyroid nodule
Gräfe W, Scheibe S, Schwarz J, Liebig L, Voigt K, Schübel J · 2025
16
Resurgence of Iodine Deficiency in the United States During Pregnancy: Potential Implications for Cognitive Development in Children
Daniel KS, Mangano KM · 2025
17
Nutritional Status of Iodine and Association with Iron, Selenium, and Zinc in Population Studies: A Systematic Review and Meta-Analysis
Lopes SO, Mayer EM, Azevedo FM, Candido AC, Bittencourt JM, Morais DC et al. · 2025
18
Global, regional, and national burden of iodine deficiency for women of reproductive age, 1990-2021: a systematic analysis based on the Global Burden of Disease Study 2021
Wang T, Tong J, Liu Y, Liu Y, Xu H, Liu Y · 2025
19
A Scoping Review on Iodine Status and Fertility: Results From Human Studies
Nazeri P, Chashmyazdan M, Masoumi M, Bagheri M, Taghva Nakhjiri M, Shafaatdoost M et al. · 2025
20
Impact of consuming an environmentally protective diet on micronutrients: a systematic literature review
Leonard UM, Leydon CL, Arranz E, Kiely ME · 2024
21
Maternal Lifestyle Factors Affecting Breast Milk Composition and Infant Health: A Systematic Review
Favara G, Maugeri A, Barchitta M, Lanza E, Magnano San Lio R, Agodi A · 2024
22
Effect of iodine nutritional status on the recurrence of hyperthyroidism and antithyroid drug efficacy in adult patients with Graves' disease: a systemic review
Xie Q, Zhang X, Ma J, Lu X, Zhang Y, Tong N · 2023
23
A systematic review of iodine intake in children, adults, and pregnant women in Europe-comparison against dietary recommendations and evaluation of dietary iodine sources
Bath SC, Verkaik-Kloosterman J, Sabatier M, Ter Borg S, Eilander A, Hora K et al. · 2022
24
Iodine and mental development of children 5 years old and under: a systematic review and meta-analysis
Bougma K, Aboud FE, Harding KB, Marquis GS · 2013
25
Effect of iodine supplementation in pregnancy on child development and other clinical outcomes: a systematic review of randomized controlled trials
Zhou SJ, Anderson AJ, Gibson RA, Makrides M · 2013
26
Benefits of docosahexaenoic acid, folic acid, vitamin D and iodine on foetal and infant brain development and function following maternal supplementation during pregnancy and lactation
Morse NL · 2012
27
Time-to-conception and clinical pregnancy rate with a myo-inositol, probiotics, and micronutrient supplement: secondary outcomes of the NiPPeR randomized trial
Chan SY, Barton SJ, Loy SL, Chang HF, Titcombe P, Wong JT et al. · 2023
28
Consumption of multiple micronutrients or small-quantity lipid-based nutrient supplements containing iodine at the recommended dose during pregnancy, compared with iron and folic acid, does not affect women's urinary iodine concentration in rural Malawi: a secondary outcome analysis of the iLiNS DYAD trial
Adu-Afarwuah S, Arnold CD, Maleta K, Ashorn P, Ashorn U, Jorgensen JM et al. · 2021
29
TSH Mediated the Effect of Iodized Salt on Child Cognition in a Randomized Clinical Trial
Mohammed H, Marquis GS, Aboud F, Bougma K, Samuel A · 2021
30
Pre-pregnancy iodized salt improved children's cognitive development in randomized trial in Ethiopia
Mohammed H, Marquis GS, Aboud F, Bougma K, Samuel A · 2020
31
The Effect of Quintuply-Fortified Salt on the Gut Microbiome of Nonpregnant Women of Reproductive Age in Punjab, India: A Substudy of a Randomized, Community-Based Trial
Thompson L, Goh YE, Jamwal M, Singh BL, Brar GK, Arnold CD et al. · 2025
32
Effects of quintuply-fortified salt on the micronutrient status of females of reproductive age in Punjab, India: a randomized, community-based trial
Goh YE, Duggal M, Das R, Manger MS, Jamwal M, Singh BL et al. · 2025
33
Effects of an Iodine-Containing Prenatal Multiple Micronutrient on Maternal and Infant Iodine Status and Thyroid Function: A Randomized Trial in The Gambia
Eriksen KG, Andersson M, Hunziker S, Zimmermann MB, Moore SE · 2020
34
Behavior change intervention to sustain iodide salt utilization in households in Ethiopia and study of the effect of iodine status on the growth of young children: community trial
Ferede A, Abera M, Belachew T · 2026
35
Effect of iodine supplementation in pregnant women on child neurodevelopment: a randomised, double-blind, placebo-controlled trial
Gowachirapant S, Jaiswal N, Melse-Boonstra A, Galetti V, Stinca S, Mackenzie I et al. · 2017
36
Oral iodine supplementation does not reduce neutralizing antibody responses to oral poliovirus vaccine
Taffs RE, Enterline JC, Rusmil K, Muhilal, Suwardi SS, Rustama D et al. · 1999
37
Iodine Supplementation in Mildly Iodine-Deficient Pregnant Women Does Not Improve Maternal Thyroid Function or Child Development: A Secondary Analysis of a Randomized Controlled Trial
Verhagen NJE, Gowachirapant S, Winichagoon P, Andersson M, Melse-Boonstra A, Zimmermann MB · 2020
38
Effects of Quintuply-Fortified Salt on the Micronutrient Status of Children 12 to 59 Months of Age in Punjab, India: Results from a Randomized, Community-Based, Household Trial
Long JM, Goh YE, Duggal M, Das R, Manger MS, Jamwal M et al. · 2026
39
Optimal iodine supplementation during antithyroid drug therapy for Graves' disease is associated with lower recurrence rates than iodine restriction
Huang H, Shi Y, Liang B, Cai H, Cai Q, Lin R · 2018
40
Folic acid fortification of iodized salt improves the folate status of nonpregnant adult Ethiopian females and does not impair their iodine status: a community-based, household-randomized, dose-response trial
Tessema M, Nane D, Woldeyohannes M, Agbemafle I, McDonald CM, Arnold CD et al. · 2026
41
Provision of Salt at No Cost Does Not Affect Total Discretionary Salt Intakes among Adult Females in Ethiopia: Secondary Analysis of a Community-Based Intervention Trial
Nane D, Fereja M, Agbemafle I, Arnold CD, Woldeyohannes M, McDonald CM et al. · 2026
42
Selenium and iodine supplementation of rural Tibetan children affected by Kashin-Beck osteoarthropathy
Moreno-Reyes R, Mathieu F, Boelaert M, Begaux F, Suetens C, Rivera MT et al. · 2003
43
Iodine supplementation improves cognition in iodine-deficient schoolchildren in Albania: a randomized, controlled, double-blind study
Zimmermann MB, Connolly K, Bozo M, Bridson J, Rohner F, Grimci L · 2006
44
Cognitive and motor functions of iodine-deficient but euthyroid children in Bangladesh do not benefit from iodized poppy seed oil (Lipiodol)
Huda SN, Grantham-McGregor SM, Tomkins A · 2001
45
Direct iodine supplementation of infants versus supplementation of their breastfeeding mothers: a double-blind, randomised, placebo-controlled trial
Bouhouch RR, Bouhouch S, Cherkaoui M, Aboussad A, Stinca S, Haldimann M et al. · 2014
46
A randomized, double-blind study of iodine supplementation during pregnancy in Sweden: pilot evaluation of maternal iodine status and thyroid function
Manousou S, Eggertsen R, Hulthén L, Filipsson Nyström H · 2021
47
Improved iodine status is associated with improved mental performance of schoolchildren in Benin
van den Briel T, West CE, Bleichrodt N, van de Vijver FJ, Ategbo EA, Hautvast JG · 2000
48
Iodine supplementation improves cognition in mildly iodine-deficient children
Gordon RC, Rose MC, Skeaff SA, Gray AR, Morgan KM, Ruffman T · 2009
49
Iodine Supplementation Decreases Hypercholesterolemia in Iodine-Deficient, Overweight Women: A Randomized Controlled Trial
Herter-Aeberli I, Cherkaoui M, El Ansari N, Rohner R, Stinca S, Chabaa L et al. · 2015
50
Iodine increases pulmonary type I interferon responses and decreases covid-19 disease severity: Results from an open label randomized clinical trial
Traksel R, Broen J, van Henten A, Königs M, Raj A, van Eyndhoven L et al. · 2026
51
Effects of Two Weekly Servings of Cod for 16 Weeks in Pregnancy on Maternal Iodine Status and Infant Neurodevelopment: Mommy's Food, a Randomized-Controlled Trial
Markhus MW, Hysing M, Midtbø LK, Nerhus I, Næss S, Aakre I et al. · 2021
52
The Effect of Quintuply-Fortified Salt on the Gut Microbiome of Young Children 1-5 y of Age in Punjab, India; A Substudy of a Randomized, Community-Based Trial
Thompson L, Goh YE, Jamwal M, Singh BL, Brar GK, Arnold CD et al. · 2025
53
Does maternal iodine supplementation during the lactation have a positive impact on neurodevelopment of children? Three-year follow up of a randomized controlled trial
Nazeri P, Tahmasebinejad Z, Pearce EN, Zarezadeh Z, Tajeddini T, Mirmiran P et al. · 2021
54
Iodine Supplementation of Mildly Iodine-Deficient Adults Lowers Thyroglobulin: A Randomized Controlled Trial
Ma ZF, Venn BJ, Manning PJ, Cameron CM, Skeaff SA · 2016
55
Iodine Supplementation throughout Pregnancy Does Not Prevent the Drop in FT4 in the Second and Third Trimesters in Women with Normal Initial Thyroid Function
Brucker-Davis F, Panaïa-Ferrari P, Gal J, Fénichel P, Hiéronimus S · 2013
56
Relative impact of iodine supplementation and maternal smoking on cord blood thyroglobulin in pregnant women with normal thyroid function
Hiéronimus S, Ferrari P, Gal J, Berthier F, Azoulay S, Bongain A et al. · 2013
57
The effect of supraphysiologic levels of iodine on patients with cyclic mastalgia
Kessler JH · 2004
58
Iodine supplementation of lactating women and assessment of infant visual information processing and maternal and infant thyroid function: A randomized trial
Gebreegziabher T, Woltamo T, Thomas DG, Kennedy TS, Stoecker BJ · 2019
59
Selenium and iodine supplementation: effect on thyroid function of older New Zealanders
Thomson CD, Campbell JM, Miller J, Skeaff SA, Livingstone V · 2009
60
Evaluation of the Effectiveness of Hyodine on Healing of Diabetic Foot Ulcer: A Randomized Single-Blind Controlled Trial
Razmandeh R, Abbaspour F, Yazdanpanah L, Shahbazi S, Heidari M, Tabatabaei-Malazy O et al. · 2026
61
Effects of oral iodine supplementation in very low birth weight preterm infants for the prevention of thyroid function alterations during the neonatal period: results of a randomised assessor-blinded pilot trial and neurodevelopmental outcomes at 24 months
Ares S, Saenz-Rico B, Arnaez J, Diez-Sebastian J, Omeñaca F, Bernal J · 2022
62
Oral iodine supplementation in very low birth weight infants. Thyroid function and Neurodevelopmental follow up at 24 months. A Randomized Clinical Trial
Ares S, SAENZ-RICO B, ARNAEZ J, Diez-Sebastian J, Omeñaca F, Bernal J · 2021
63
The Effects of Iodine Supplementation in Pregnancy on Iodine Status, Thyroglobulin Levels and Thyroid Function Parameters: Results from a Randomized Controlled Clinical Trial in a Mild-to-Moderate Iodine Deficiency Area
Censi S, Watutantrige-Fernando S, Groccia G, Manso J, Plebani M, Faggian D et al. · 2019
64
A Randomized Crossover Trial of Acceptability of Quadruple-Fortified Salt in Women and their Households in Southern India
Guetterman HM, Rajagopalan K, Fox AM, Johnson CB, Fothergill A, George N et al. · 2025
65
Efficacy and safety of iodine in the postpartum period in an area of mild iodine deficiency
Reinhardt W, Kohl S, Hollmann D, Klapp G, Benker G, Reinwein D et al. · 1998
66
Comparison of two different doses of iodide in the prevention of gestational goiter in marginal iodine deficiency: a longitudinal study
Antonangeli L, Maccherini D, Cavaliere R, Di Giulio C, Reinhardt B, Pinchera A et al. · 2002
67
Postpartum thyroid dysfunction in pregnant thyroid peroxidase antibody-positive women living in an area with mild to moderate iodine deficiency: is iodine supplementation safe?
Nøhr SB, Jørgensen A, Pedersen KM, Laurberg P · 2000
68
The effect of iodine supplementation in pregnancy on early childhood neurodevelopment and clinical outcomes: results of an aborted randomised placebo-controlled trial
Zhou SJ, Skeaff SA, Ryan P, Doyle LW, Anderson PJ, Kornman L et al. · 2015
69
Iodine therapy for thyroidectomy patients exhibiting high thyroid-stimulating hormone values: a randomised study
Taylor JD, Radcliffe SN, Basu PK, Atkins P · 1993
70
Amelioration of some pregnancy-associated variations in thyroid function by iodine supplementation
Pedersen KM, Laurberg P, Iversen E, Knudsen PR, Gregersen HE, Rasmussen OS et al. · 1993
71
Effects of Daily Kelp (Laminaria japonica) Intake on Body Composition, Serum Lipid Levels, and Thyroid Hormone Levels in Healthy Japanese Adults: A Randomized, Double-Blind Study
Aoe S, Yamanaka C, Ohtoshi H, Nakamura F, Fujiwara S · 2021
72
Thyroidectomy: is Lugol's iodine necessary?
Coyle PJ, Mitchell JE · 1982
73
The effect of preoperative Lugol's iodine on intraoperative bleeding in patients with hyperthyroidism
Yilmaz Y, Kamer KE, Ureyen O, Sari E, Acar T, Karahalli O · 2016
74
Bioavailability of iodine from a meal consisting of sushi and a wakame seaweed salad-A randomized crossover trial
Aakre I, Tveit IB, Myrmel LS, Fjære E, Ballance S, Rosendal-Riise H · 2023
75
The effect of preoperative Lugol's iodine on thyroid blood flow in patients with Graves' hyperthyroidism
Chang DC, Wheeler MH, Woodcock JP, Curley I, Lazarus JR, Fung H et al. · 1987
76
Serum Folate Forms Show Dose-Dependent Increases in Nonpregnant Ethiopian Women of Reproductive Age Participating in a Randomized Controlled Trial with Double-Fortified Salt Containing Iodine and Folic Acid
Pfeiffer CM, Fazili Z, Arnold CD, Woldeyohannes M, Nane D, Fereja M et al. · 2026
77
Pairwise fitting of piecewise mixed models for the joint modeling of multivariate longitudinal outcomes, in a randomized crossover trial
Mwangi M, Molenberghs G, Njagi EN, Mwalili S, Braekers R, Florez AJ et al. · 2024
78
A Study to Improve the Vitamin A and Iodine Status of Pregnant Women through a Multiple Micronutrient Fortified Salt
Vinod Kumar M, Sankarapandian M, Erhardt J · 2022
79
Improved first trimester maternal iodine status with preconception supplementation: The Women First Trial
Young AE, Kemp JF, Uhlson C, Westcott JL, Ali SA, Saleem S et al. · 2021
80
Comparison of the Effectiveness of Universal and Targeted Iodine Supplementation in Pregnant Women: A Randomized Controlled Trial
Tinna T, Ounjaijean S, Tongsong T, Traisrisilp K · 2020
81
Adjuvant Effect of Molecular Iodine in Conventional Chemotherapy for Breast Cancer. Randomized Pilot Study
Moreno-Vega A, Vega-Riveroll L, Ayala T, Peralta G, Torres-Martel JM, Rojas J et al. · 2019
82
Lactating Mothers and Infants Residing in an Area with an Effective Salt Iodization Program Have No Need for Iodine Supplements: Results from a Double-Blind, Placebo-Controlled, Randomized Controlled Trial
Nazeri P, Tahmasebinejad Z, Mehrabi Y, Hedayati M, Mirmiran P, Azizi F · 2018
83
Effects of salso-bromo-iodine thermal water in children suffering from otitis media with effusion: a randomized controlled pilot study
La Mantia I, Andaloro C · 2018
84
A Paleolithic-type diet results in iodine deficiency: a 2-year randomized trial in postmenopausal obese women
Manousou S, Stål M, Larsson C, Mellberg C, Lindahl B, Eggertsen R et al. · 2018
85
Comparison of two sources of iodine delivery on breast milk iodine and maternal and infant urinary iodine concentrations in southern Ethiopia: A randomized trial
Gebreegziabher T, Stoecker BJ · 2017
86
Correlation between Iodine Supplement in Pregnancy and Neonatal TSH Level
Dandamrongrak P, Chawanpaiboon S · 2016
87
Infant survival is improved by oral iodine supplementation
Cobra C, Muhilal, Rusmil K, Rustama D, Djatnika, Suwardi SS et al. · 1997
88
A randomized trial for the treatment of mild iodine deficiency during pregnancy: maternal and neonatal effects
Glinoer D, De Nayer P, Delange F, Lemone M, Toppet V, Spehl M et al. · 1995
89
Iodine supplementation: comparison of oral or intramuscular iodized oil with oral potassium iodide. A controlled trial in Zaire
Phillips DI, Lusty TD, Osmond C, Church D · 1988
90
Iodine replacement in fibrocystic disease of the breast
Ghent WR, Eskin BA, Low DA, Hill LP · 1993
91
Folic Acid-Fortified Iodized Salt and Serum Folate Levels in Reproductive-Aged Women of Rural India: A Nonrandomized Controlled Trial
Pattisapu JV, Manda VV, Kottakki MNR, Kajana PM, Kancherla V, Bhaganagarapu HR et al. · 2024
92
A Modified Iodine Balance Study to Explore the Recommended Nutrient Intake of Iodine in Chinese Preschool Children Aged 3 to 6 Years
Yang R, Jin Q, An D, Lv D, Wei Y, Pearce EN et al. · 2026
93
Effects of maternal iodine supplementation during pregnancy
Pharoah PO, Connolly KJ · 1991
94
Iodine supplementation with oral or intramuscular iodized oil. A two-year follow-up of a comparative trial
Phillips DI, Osmond C · 1989
95
Household iodized salt consumption and iodine status in women of reproductive age in Angola: a cross-sectional study
Catumbela E, de Lemos M, Nimi T, Têmbua C, Paixão JP, Kapapelo A et al. · 2025
96
Maternal Knowledge and Practices Regarding Iodized Salt and Their Association with Nutritional Status and Cognitive Performance of School-Going Pre-Adolescent Children (6–12 Years) in Tehsil Katlang, Khyber Pakhtunkhwa, Pakistan
Jamal¹ H, Ijaz² F, Ullah³ I, Din ZU, Ambreen S, Ullah I · 2026
97
The association of urine markers of iodine intake with development and growth among children in rural Uganda: a secondary analysis of a randomised education trial
Atukunda P, Muhoozi GK, Diep LM, Berg JP, Westerberg AC, Iversen PO · 2021
98
Iodine intake assessment in the staff of a Porto region university (Portugal): the iMC Salt trial
Machado A, Gonçalves C, Moreira P, Pinho O, Padrão P, Silva-Santos T et al. · 2023
99
Sustained Elimination of Iodine Deficiency Within the Third Decade After Compulsory Iodine Supplementation Policy in the South of Iran: A Population-Based Cross-Sectional Study
Jeddi M, Habib A, Salehi A · 2023
100
Iodine deficiency and its association with periodontitis: A randomized controlled triple-blinded clinical study
Eminoğlu DÖ, Laloglu E, Kasali K, Aydin T, Bulut E, Yaliniz G et al. · 2025
101
Urinary iodine excretion in mothers and their breast-fed children in relation to other childhood nutritional parameters
Akanji AO, Mainasara AS, Akinlade KS · 1996
102
Impact of habitual seaweed consumption on iodine nutrition and thyroid function: a non-randomized pre-post clinical study
Aakre I, Vogt EC, Myrmel LS, Lundebye AK, Helland OB, Henjum S et al. · 2026
103
Micronutrient Biomarker Selection and Assay Methods and Performance in Double-Blind, Randomized, Controlled Micronutrient Dose Response (MiNDR) Trials among Women of Reproductive Age and Pregnant Women in Rural Bangladesh
Bandyopadhyay S, Roy AK, Baker S, Stephenson KK, Ge X, Wang Y et al. · 2025
104
Iodized salt has large impacts on child health and test scores in Ethiopia
Alemu R, Tafere K, Gashu D, Joy E, Bailey E, Lark R et al. · 2025
105
Global, regional and national trends in the burden of nutritional deficiencies in children, 1990-2021
Liu Z, Liu Y, Yang J, Yan L, Li Q, Gao Y · 2025
106
Association of Mild Iodine Insufficiency during Pregnancy with Child Neurodevelopment in Patients with Subclinical Hypothyroidism or Hypothyroxinemia
Casey BM, Mele L, Peaceman AM, Varner MW, Reddy UM, Wapner RJ et al. · 2024
107
Nomogram Model Based on Iodine Nutrition and Clinical Characteristics of Papillary Thyroid Carcinoma to Predict Lateral Lymph Node Metastasis
Wang J, Gao Y, Zong Y, Gao W, Wang X, Sun J et al. · 2023
108
Maternal Iodine Status During Pregnancy Is Not Consistently Associated with Attention-Deficit Hyperactivity Disorder or Autistic Traits in Children
Levie D, Bath SC, Guxens M, Korevaar TIM, Dineva M, Fano E et al. · 2020
109
Iodine Status After Bariatric Surgery-a Prospective 10-Year Report from the Swedish Obese Subjects (SOS) Study
Manousou S, Carlsson LMS, Eggertsen R, Hulthén L, Jacobson P, Landin-Wilhelmsen K et al. · 2018
110
Does Surgery Without Lugol's Solution Pretreatment for Graves' Disease Increase Surgical Morbidity?
Mercier F, Bonal M, Fanget F, Maillard L, Laplace N, Peix JL et al. · 2018
111
Iron status influences the efficacy of iodine prophylaxis in goitrous children in Côte d'Ivoire
Zimmermann MB · 2002
112
The Increasing Prevalence of Autism Spectrum Disorder in the U.S. and Its Implications for Pediatric Micronutrient Status: A Narrative Review of Case Reports and Series
Daniel KS, Jiang Q, Wood MS · 2025
113
Iodine in Health and Disease: A Comprehensive Review
Delić T, Karanović Štambuk S · 2026
114
Iodine Supplementation Before, During and After Pregnancy
Grossklaus R, Liesenkötter KP, Lawrenz B, Thieme F · 2026
115
Iodine and Thyroid Dysfunction in Ageing: Nutritional, Pharmacologic, and Microbial Modifiers in Older Adults
Zugravu CA, Petre M, Constantin C · 2026
116
Evolving Concepts in Gestational Iodine Requirements
Milionis C, Koukkou EG, Markou KB, Ilias I · 2026
117
Iodine deficiency in the UK - should we take it with a pinch of salt?
Bath SC · 2026
118
Unraveling the Origins of Thyroid Nodules: Inflammation, Hormones, Toxins, and Micronutrient Interactions
Mazza AD · 2026
119
Micronutrient balance and brain function: neuropsychological, metabolic, and clinical interactions
López-Sebastiani V, Quiroz-Cornejo KV, Arellano-Salazar MP, Monje-Bolivar F, Samillan VJ · 2026
120
Micronutrient Status, Health Implications, and Assessment Aproaches in Older Adults: A Narrative Review of Recent Studies
Finta H, Avram C, Buicu CF, Ceana DE, Moldovan I, Ruta F · 2026
121
Beyond thyroid dysfunction: the systemic impact of iodine excess
Khudair A, Khudair A, Niinuma SA, Habib H, Butler AE · 2025
122
Effect of Iodine Nutrition During Pregnancy and Lactation on Child Cognitive Outcomes: A Review
Ma ZF, Brough L · 2025
123
Analytical Review on Nutritional Deficiencies in Vegan Diets: Risks, Prevention, and Optimal Strategies
Malhotra A, Lakade A · 2025
124
Recent advances of trace elements in autoimmune thyroid disease
Li S, Xu Q, Wang S, Peng H, Liu Y · 2025
125
Nutritional supplementation in pregnant, lactating women and young children following a plant-based diet: A narrative review of the evidence
Herrero Jiménez MP, Del Pozo de la Calle S, Cuadrado Vives C, Escobar Sáez D · 2025
126
Diet in Pregnancy: A Review of Current Challenges and Recommendations. A British Nutrition Foundation Briefing Paper
Hart KH, Hill AJ, Gonzalez JT, de la Hunty A, Gallagher AM, Stanner SA · 2025
127
Critical Role of Iodine and Thyroid Hormones During Pregnancy
Moreno-Reyes R, Fuentes Peña C, Nuñez JF, Sánchez MB, Carvajal JJ, Roble K et al. · 2025
128
Plant-based diets for sustainability and health - but are we ignoring vital micronutrients?
Bath SC · 2025
129
Are Dietary Habits the Missing Link Between Hashimoto's Thyroiditis and Osteoporosis?
Vergatti A, Abate V, Garofano F, Fiore A, De Filippo G, Strazzullo P et al. · 2025
130
Scoping review of micronutrient imbalances, clinical manifestations, and interventions
English K, Uwibambe C, Daniels P, Dzukey E · 2025
131
Nutrition in early life, epigenetics and lifelong health - evidence from cohort and intervention studies
Godfrey KM, Costello P, El-Heis S · 2025
132
Cardiac Manifestations of Nutritional Deficiencies
Huang L, Huhulea EN, Enwere C, Aifuwa E, Frishman WH, Aronow WS · 2025
133
Aeronutrient Therapy: A New Frontier in Systemic Drug Delivery
Robinson SR, Trivedi MS, Fayet-Moore F · 2025
134
From Diet to Drugs: Integrative Perspectives on Iodine, Thyroid Dysfunction, and Microbiota in the Elderly
Zugravu C, Petre M, Constantin C · 2025
135
The impact of environmental factors and contaminants on thyroid function and disease from fetal to adult life: current evidence and future directions
Street ME, Shulhai AM, Petraroli M, Patianna V, Donini V, Giudice A et al. · 2024
136
The Role of Nutrition on Thyroid Function
Shulhai AM, Rotondo R, Petraroli M, Patianna V, Predieri B, Iughetti L et al. · 2024
137
Nutritional Status of Breastfeeding Mothers and Impact of Diet and Dietary Supplementation: A Narrative Review
Carretero-Krug A, Montero-Bravo A, Morais-Moreno C, Puga AM, Samaniego-Vaesken ML, Partearroyo T et al. · 2024
138
The Impact of Environmental Factors on the Development of Autoimmune Thyroiditis-Review
Cyna W, Wojciechowska A, Szybiak-Skora W, Lacka K · 2024
139
An update: maternal iodine supplementation, thyroid function tests, and child neurodevelopmental outcomes
Nguyen CT · 2023
140
Multiple nutritional factors and thyroid disease, with particular reference to autoimmune thyroid disease
Rayman MP · 2019
141
Multiple Nutritional Factors and the Risk of Hashimoto's Thyroiditis
Hu S, Rayman MP · 2017
142
Pre-Operative Lugol's Iodine Treatment in the Management of Patients Undergoing Thyroidectomy for Graves' Disease: A Review of the Literature
Hope N, Kelly A · 2017
143
Statistical design considerations applicable to clinical trials of iodine supplementation in pregnant women who may be mildly iodine deficient
Troendle JF · 2016
144
Consequences of iodine deficiency and excess in pregnant women: an overview of current knowns and unknowns
Pearce EN, Lazarus JH, Moreno-Reyes R, Zimmermann MB · 2016
145
Iodine supplementation in pregnancy - is it time?
Taylor PN, Vaidya B · 2016
146
Thyroid and iodine nutritional status: a UK perspective
Vanderpump M · 2014
147
Iodine deficiency in pregnancy: the effect on neurodevelopment in the child
Skeaff SA · 2011
148
Hypothyroxinemia and pregnancy
Negro R, Soldin OP, Obregon MJ, Stagnaro-Green A · 2011
149
Potential cost-effectiveness of nutrition interventions to prevent adverse pregnancy outcomes in the developing world
Rouse DJ · 2003

Every statement on this page carries its evidence tier — proven, plausible or hypothesis — and leads to the original work. The decision in the individual case rests with the practitioner; we provide the connections.