Iodine Intake Calculator
Iodine mcg from diet and pills against RDA and UL.
What it does
Iodine feeds the thyroid a pinch a day: 150 mcg runs adult hormones while pregnancy and lactation ask more. Salt, seafood, and pills stack toward that line, and kelp can overshoot it alone.
The tool above takes salt grams, seafood servings, and supplement label mcg by life stage. It returns total mcg, the RDA share, and the safety verdict.
The default adult with 3 g salt plus a 150 mcg pill totals 285 mcg, or 190% of RDA, within safe range. The heavy case of 10 g salt with 2 seafood servings and 500 mcg hits 1250, over the 1,100 limit.
NIH supplement guidance fixes the 150/220/290 RDA ladder with the 1,100 adult ceiling. Federal labeling rules repeat 150 mcg as the Daily Value behind every supplement panel.
Food iodine wobbles by soil, brand, and canister age, so totals stay estimates. Dairy and eggs add uncounted background; symptoms and dosing decisions belong with labs and clinicians.
How to use
- Pick adult, pregnant, or lactating.
- Type iodized salt grams.
- Type seafood servings.
- Type supplement mcg from labels.
- Read total first.
- Read RDA share and safety beside it.
Formula
- salt
- Iodized salt grams, about 45 mcg each.
- seafood
- Seafood servings near 150 mcg each.
- supplement
- Label mcg from pills and kelp.
- RDA
- 150 adult, 220 pregnant, 290 lactating.
NIH Office of Dietary Supplements sets adult RDA at 150 mcg with 220 in pregnancy, 290 in lactation, and a 1,100 adult upper limit. Federal Daily Value rules list 150 mcg for labeling. Salt near 45 mcg per gram and seafood near 150 per serving are planning estimates; labels rule where printed.
Worked example
Example: salted meals plus a supplement
Defaults: adult, 3 g salt, no seafood, 150 mcg supplement.
- Salt: 3 g iodized at about 45 mcg/g = 135 mcg.
- Seafood: none today, 0 mcg.
- Supplement: label 150 mcg.
- Total: 135 + 0 + 150 = 285 mcg.
- Share: 285 / 150 = 190% of adult RDA.
- Tool shows 285 mcg, 190% of RDA, Within safe range.
Reference table
| Group | RDA | UL |
|---|---|---|
| Adults | 150 | 1,100 |
| Pregnancy | 220 | 1,100 |
| Lactating | 290 | 1,100 |
| Kids 1 to 8 | 90 | 200 to 300 |
Limits
- Estimates; food content varies.
- Dairy and eggs uncounted here.
- Not a deficiency diagnosis.
- Labels beat planning factors.
Common mistakes
- Ignoring kelp megadoses.
- Counting non iodized salt.
- Stacking multiple iodine pills.
- Reading RDA as a target to exceed.
- Self dosing thyroid symptoms.
Try it yourself
Quick checks. Answers sit tucked under each question.
10 g salt, 2 seafood, 500 mcg pill?
450 + 300 + 500 = 1250 mcg, 833% of RDA, over the limit.
Nothing logged?
0 mcg, 0% of RDA, within safe range but far under goal.
Salt 100 g?
Over 50 g salt is a diet problem first: log realistic amounts.
Questions
How much daily?
150 mcg adults, 220 pregnancy, 290 lactating, 1,100 upper limit for adults. Kids scale lower.
Why iodine matters?
Thyroid hormones run metabolism, growth, and fetal brain development. Too little and too much both harm.
Iodized salt content?
About 45 mcg per gram, so 3 g gives 135. Content varies by brand and age of the canister.
Food sources?
Sea fish, seaweed, dairy, and eggs lead; plants follow local soil iodine.
Kelp supplements?
Kelp tablets swing wildly into thousands of mcg. Read labels and count them here.
Diagnose deficiency?
No, this estimates intake. Thyroid symptoms need labs and a clinician, not arithmetic.
Sources
- NIH Office of Dietary Supplements: iodine fact sheet
- 21 CFR 101.36: Daily Value 150 mcg (Cornell LII)