Selenium upper limit: how much is too much per day?

For adults 19 and older, the upper limit (UL) of selenium is 400 mcg per day, counting all sources together, food and supplements included.

Ages 14 and older · Source: National Academies Dietary Reference Intakes · Data as of 2026-10-03

Every life stage

Group	Age	RDA or AI mcg/day	UL mcg/day
Male	14–18	55 RDA	400
Male	19–30	55 RDA	400
Male	31–50	55 RDA	400
Male	51–70	55 RDA	400
Male	71+	55 RDA	400
Female	14–18	55 RDA	400
Female	19–30	55 RDA	400
Female	31–50	55 RDA	400
Female	51–70	55 RDA	400
Female	71+	55 RDA	400
Pregnancy	14–18	60 RDA	400
Pregnancy	19–30	60 RDA	400
Pregnancy	31–50	60 RDA	400
Lactation	14–18	70 RDA	400
Lactation	19–30	70 RDA	400
Lactation	31–50	70 RDA	400

RDA = Recommended Dietary Allowance; AI = Adequate Intake, used where there is not enough data for an RDA. UL = Tolerable Upper Intake Level. “Not set” means the tables give no value. Ages under 14 are in the National Academies tables and are not covered here.

What counts toward the limit

This UL covers your total intake: selenium from food, water and supplements added together.

Table footnote, as recorded in Ceiling’s data: “UL is total intake from food, water and supplements.”

How Ceiling uses this

Ceiling adds up every supplement you scan and compares your daily total with this number. Ceiling counts supplements only, so food and water come on top of the total it shows. Ceiling is coming soon on iPhone. No account; everything stays on your iPhone.

What is the upper limit of selenium?