Iodine

What it is · too little · too much · daily reference values by country

For reference only. This is not a diagnosis or a prescription. If you have concerns, talk to a doctor or pharmacist.

What it is

Iodine is an essential trace element and a main component of thyroid hormones. (Korea Ministry of Health and Welfare · Korean Nutrition Society)
Iodine is an essential nutrient. It is an integral component of thyroid hormones and therefore contributes to the regulation of energy metabolism. It is particularly important during early growth, development, and maturation of most organs. (European Food Safety Authority)

Getting too little

Too little iodine can lead to goiter, hypothyroidism, impaired nerve development in the fetus, and cretinism. (Korea Ministry of Health and Welfare · Korean Nutrition Society)
Insufficient intake of iodine can lead to impaired thyroid function and disorders at all stages of development, particularly in pregnancy and infancy. (European Food Safety Authority)

Getting too much

Hyperthyroidism, iodine-induced thyroiditis, and worsening of autoimmune disease have been reported after excess iodine intake. (Korea Ministry of Health and Welfare · Korean Nutrition Society)
Cases such as hyperthyroidism from thyroid dysfunction and worsening of thyroid malignant tumors have been reported when iodine was taken in excess for a long time. (Korea Ministry of Health and Welfare · Korean Nutrition Society)

Daily reference values by country

Korea · US · EU — tap to open

These tables are daily reference values for healthy people. Numbers in the text above are a different kind of value, and you cannot diagnose yourself from them. How to read RDA, AI and UL

Korea — 2025 Dietary Reference Intakes for Koreans (Ministry of Health and Welfare)

Group	EAR	RNI	AI	UL
0–5 months			130 μg	Checking
6–11 months			180 μg	Checking
1–2 years	50 μg	70 μg		Checking
3–5 years	65 μg	90 μg		Checking
Male · 6–8 years	75 μg	100 μg		Checking
Male · 9–11 years	80 μg	110 μg		Checking
Male · 12–14 years	100 μg	140 μg		Checking
Male · 15–18 years	100 μg	140 μg		Checking
Male · 19–29 years	100 μg	150 μg		Checking
Male · 30–49 years	100 μg	150 μg		Checking
Male · 50–64 years	100 μg	150 μg		Checking
Male · 65–74 years	100 μg	150 μg		Checking
Male · 75+ years	100 μg	150 μg		Checking
Female · 6–8 years	75 μg	100 μg		Checking
Female · 9–11 years	80 μg	110 μg		Checking
Female · 12–14 years	100 μg	140 μg		Checking
Female · 15–18 years	100 μg	140 μg		Checking
Female · 19–29 years	100 μg	150 μg		Checking
Female · 30–49 years	100 μg	150 μg		Checking
Female · 50–64 years	100 μg	150 μg		Checking
Female · 65–74 years	100 μg	150 μg		Checking
Female · 75+ years	100 μg	150 μg		Checking
Pregnancy	+60 μg	+90 μg		—
Lactation	+130 μg	+190 μg		—

US — NASEM (National Academies)

Group	EAR	RDA	AI	UL
1–3 years	65 μg	90 μg		200 μg
4–8 years	65 μg	90 μg		300 μg
Male · 9–13 years	73 μg	120 μg		600 μg
Male · 14–18 years	95 μg	150 μg		900 μg
Male · 19–30 years	95 μg	150 μg		1100 μg
Male · 31–50 years	95 μg	150 μg		1100 μg
Male · 51–70 years	95 μg	150 μg		1100 μg
Male · 71+ years	95 μg	150 μg		1100 μg
Female · 9–13 years	73 μg	120 μg		600 μg
Female · 14–18 years	95 μg	150 μg		900 μg
Female · 19–30 years	95 μg	150 μg		1100 μg
Female · 31–50 years	95 μg	150 μg		1100 μg
Female · 51–70 years	95 μg	150 μg		1100 μg
Female · 71+ years	95 μg	150 μg		1100 μg
Pregnancy · 14–18 years	160 μg	220 μg		900 μg
Pregnancy · 19–30 years	160 μg	220 μg		1100 μg
Pregnancy · 31–50 years	160 μg	220 μg		1100 μg
Lactation · 14–18 years	209 μg	290 μg		900 μg
Lactation · 19–30 years	209 μg	290 μg		1100 μg
Lactation · 31–50 years	209 μg	290 μg		1100 μg
0–6 months			110 μg	—
7–12 months			130 μg	—

UL — applies to: Unless otherwise specified, the UL represents total intake from food, water, and supplements.

EU — EFSA (European Food Safety Authority)

Group	AI	UL
7–11 months	70 μg
1–3 years	90 μg	200 μg
4–6 years	90 μg	250 μg
7–10 years	90 μg	300 μg
11–14 years	120 μg	450 μg
15–17 years	130 μg	500 μg
18+ years	150 μg	600 μg
Pregnancy · 18–60 years	200 μg
Lactation · 18–60 years	200 μg
Pregnancy · 18+ years		600 μg
Lactation · 18+ years		600 μg

UL — applies to: Total chronic daily intake from all dietary sources.

Sources

EFSA DRV Finder (Dietary Reference Values) · checked 2026-10-07
EFSA DRV Finder — nutrient descriptions · checked 2026-10-07
EFSA Overview on Tolerable Upper Intake Levels (v11, August 2025) · checked 2026-10-07
2025 Dietary Reference Intakes for Koreans, Vol. 3: Minerals (Korean Ministry of Health and Welfare · The Korean Nutrition Society; in Korean) · checked 2026-10-07
2025 Dietary Reference Intakes for Koreans — summary tables (Korean Ministry of Health and Welfare · The Korean Nutrition Society; in Korean) · checked 2026-10-07
NASEM Dietary Reference Intakes summary tables (Appendix J, 2019) · checked 2026-10-07

The sentences are plain-language summaries of official sources written by SuppleBoard. Each English sentence was checked against the source text by an AI reviewer before publishing. The agencies do not endorse this site. Published 2026-10-17.

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