Loading…
Check iodine intake vs RDA — see mcg/day, % of RDA and food sources.
Check iodine intake vs RDA — see mcg/day, % of RDA and food sources.
Enter values above and click Calculate — results will appear here with the formula explained.
Iodine RDA is 150 mcg daily for adults 19+ (220 mcg pregnancy, 290 mcg lactation) — the raw material for thyroid hormones T4 and T3, which set metabolic rate, brain development and body temperature. This calculator checks intake as percent of RDA; iodized-salt users typically clear it effortlessly, while sea-salt/Himalayan devotees and dairy avoiders often land at 50–80 mcg.
Source hierarchy is stark: iodized salt (~70 mcg per ¼ teaspoon) is the engineered solution that eliminated goiter in the 20th century; dairy adds 50–100 mcg daily via feed and sanitizers; seaweed swings wildly (nori ~15 mcg/sheet, kombu up to 2,500 mcg per serving — supplement-scale doses from food). Eggs, fish and bread contribute modestly.
Pregnancy is the vigilance zone: fetal brain development needs maternal iodine throughout gestation, and even mild deficiency associates with lower child IQ in cohort studies. Needs rise to 220 mcg (290 lactation) precisely when nausea, food aversions and 'clean salt' trends push intake down — prenatal vitamins with 150 mcg potassium iodide plus iodized salt close the gap deliberately.
Excess cuts both ways: chronic intakes above the 1,100 mcg UL — usually from kelp supplements, not food — can trigger thyroid dysfunction in both directions (hypo- and hyperthyroidism, especially with autoimmune thyroid disease). Kombu-heavy diets and iodine 'loading' protocols deserve the same skepticism as any megadose trend.
Goitrogens (cruciferous vegetables, soy, cassava) inhibit iodine utilization only at extreme intakes with concurrent deficiency — normal servings in iodine-sufficient diets pose no thyroid risk. Smoking (thiocyanate) competes similarly; the fix is adequate iodine, not avoiding broccoli.
This is general information: thyroid symptoms (fatigue, cold intolerance, neck swelling) warrant TSH testing, not calculator reassurance. Iodine status is best confirmed via urinary iodine in populations, serum patterns individually — intake math screens, labs decide.
Check iodine intake vs RDA — see mcg/day, % of RDA and food sources. Formula: RDA: 150 mcg 19+ (220 pregnancy, 290 lactation). Example: With 150 mcg intake, not pregnant: 100% of the 150 mcg RDA.
Iodine RDA is 150 mcg daily for adults 19+ (220 mcg pregnancy, 290 mcg lactation) — the raw material for thyroid hormones T4 and T3, which set metabolic rate, brain development and body temperature. This calculator checks intake as percent of RDA; iodized-salt users typically clear it effortlessly, while sea-salt/Himalayan devotees and dairy avoiders often land at 50–80 mcg.
Source hierarchy is stark: iodized salt (~70 mcg per ¼ teaspoon) is the engineered solution that eliminated goiter in the 20th century; dairy adds 50–100 mcg daily via feed and sanitizers; seaweed swings wildly (nori ~15 mcg/sheet, kombu up to 2,500 mcg per serving — supplement-scale doses from food). Eggs, fish and bread contribute modestly.
Pregnancy is the vigilance zone: fetal brain development needs maternal iodine throughout gestation, and even mild deficiency associates with lower child IQ in cohort studies. Needs rise to 220 mcg (290 lactation) precisely when nausea, food aversions and 'clean salt' trends push intake down — prenatal vitamins with 150 mcg potassium iodide plus iodized salt close the gap deliberately.
Excess cuts both ways: chronic intakes above the 1,100 mcg UL — usually from kelp supplements, not food — can trigger thyroid dysfunction in both directions (hypo- and hyperthyroidism, especially with autoimmune thyroid disease). Kombu-heavy diets and iodine 'loading' protocols deserve the same skepticism as any megadose trend.
Goitrogens (cruciferous vegetables, soy, cassava) inhibit iodine utilization only at extreme intakes with concurrent deficiency — normal servings in iodine-sufficient diets pose no thyroid risk. Smoking (thiocyanate) competes similarly; the fix is adequate iodine, not avoiding broccoli.
This is general information: thyroid symptoms (fatigue, cold intolerance, neck swelling) warrant TSH testing, not calculator reassurance. Iodine status is best confirmed via urinary iodine in populations, serum patterns individually — intake math screens, labs decide.
With 150 mcg intake, not pregnant: 100% of the 150 mcg RDA. A sea-salt-only cook getting 60 mcg sits at 40% — switching to iodized salt adds ~70 mcg per quarter-teaspoon and closes the gap without a single supplement.
Last reviewed: September 2026 · Report an error