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

For adults 19 and older, the upper limit (UL) of iodine is 1,100 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	150 RDA	900
Male	19–30	150 RDA	1,100
Male	31–50	150 RDA	1,100
Male	51–70	150 RDA	1,100
Male	71+	150 RDA	1,100
Female	14–18	150 RDA	900
Female	19–30	150 RDA	1,100
Female	31–50	150 RDA	1,100
Female	51–70	150 RDA	1,100
Female	71+	150 RDA	1,100
Pregnancy	14–18	220 RDA	900
Pregnancy	19–30	220 RDA	1,100
Pregnancy	31–50	220 RDA	1,100
Lactation	14–18	290 RDA	900
Lactation	19–30	290 RDA	1,100
Lactation	31–50	290 RDA	1,100

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: iodine 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 iodine?