Selenium

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

Selenium is present in the body in only tiny amounts, but it is an essential nutrient for powerful antioxidant action, thyroid hormone metabolism, immune function, and reproductive function. (Korea Ministry of Health and Welfare · Korean Nutrition Society)
Selenium is an essential dietary mineral. It is an important component of selenoproteins which belong to the human antioxidant network and regulate thyroid hormone metabolism. (European Food Safety Authority)

Getting too little

Severe selenium deficiency may cause poor nutrition of the heart muscle and raise the risk of Keshan disease. Keshan disease is said to occur mainly in children and women whose selenium intake is extremely low. (Korea Ministry of Health and Welfare · Korean Nutrition Society)
Low selenium intakes may be associated with skeletal myopathy, muscle weakness, myxoedematous cretinism (when combined with low iodine intake). Selenium deficiency may also increase the risk of developing Keshan and Kashin-Beck diseases. (European Food Safety Authority)

Getting too much

Typical harmful cases reported after excess selenium intake include garlic-smelling breath, fatigue, hair loss, nail changes, digestive problems, and abnormal peripheral nerve function. (Korea Ministry of Health and Welfare · Korean Nutrition Society)
Chronic excess selenium intake is said to lead to selenosis, with symptoms such as fatigue, digestive problems, loss of nails and hair, skin lesions, and nerve pain. (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			9 μg	Checking
6–11 months			12 μg	Checking
1–2 years	19 μg	23 μg		Checking
3–5 years	22 μg	25 μg		Checking
Male · 6–8 years	30 μg	35 μg		Checking
Male · 9–11 years	40 μg	45 μg		Checking
Male · 12–14 years	50 μg	60 μg		Checking
Male · 15–18 years	55 μg	65 μg		Checking
Male · 19–29 years	50 μg	60 μg		Checking
Male · 30–49 years	50 μg	60 μg		Checking
Male · 50–64 years	50 μg	60 μg		Checking
Male · 65–74 years	50 μg	60 μg		Checking
Male · 75+ years	50 μg	60 μg		Checking
Female · 6–8 years	30 μg	35 μg		Checking
Female · 9–11 years	40 μg	45 μg		Checking
Female · 12–14 years	50 μg	60 μg		Checking
Female · 15–18 years	55 μg	65 μg		Checking
Female · 19–29 years	50 μg	60 μg		Checking
Female · 30–49 years	50 μg	60 μg		Checking
Female · 50–64 years	50 μg	60 μg		Checking
Female · 65–74 years	50 μg	60 μg		Checking
Female · 75+ years	50 μg	60 μg		Checking
Pregnancy	+3 μg	+4 μg		Checking
Lactation	+9 μg	+10 μg		Checking

US — NASEM (National Academies)

Group	EAR	RDA	AI	UL
1–3 years	17 μg	20 μg		90 μg
4–8 years	23 μg	30 μg		150 μg
Male · 9–13 years	35 μg	40 μg		280 μg
Male · 14–18 years	45 μg	55 μg		400 μg
Male · 19–30 years	45 μg	55 μg		400 μg
Male · 31–50 years	45 μg	55 μg		400 μg
Male · 51–70 years	45 μg	55 μg		400 μg
Male · 71+ years	45 μg	55 μg		400 μg
Female · 9–13 years	35 μg	40 μg		280 μg
Female · 14–18 years	45 μg	55 μg		400 μg
Female · 19–30 years	45 μg	55 μg		400 μg
Female · 31–50 years	45 μg	55 μg		400 μg
Female · 51–70 years	45 μg	55 μg		400 μg
Female · 71+ years	45 μg	55 μg		400 μg
Pregnancy · 14–18 years	49 μg	60 μg		400 μg
Pregnancy · 19–30 years	49 μg	60 μg		400 μg
Pregnancy · 31–50 years	49 μg	60 μg		400 μg
Lactation · 14–18 years	59 μg	70 μg		400 μg
Lactation · 19–30 years	59 μg	70 μg		400 μg
Lactation · 31–50 years	59 μg	70 μg		400 μg
0–6 months			15 μg	45 μg
7–12 months			20 μg	60 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	15 μg
1–3 years	15 μg	Checking
4–6 years	20 μg	Checking
7–10 years	35 μg	Checking
11–14 years	55 μg	Checking
15–17 years	70 μg	Checking
18+ years	70 μg	Checking
Pregnancy · 18–60 years	70 μg
Lactation · 18–60 years	85 μg
Pregnancy · 18+ years		Checking
Lactation · 18+ years		Checking

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 2026-10-16.

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