Iron is a high-risk supplementwith an RDA of 18 mg and a safe upper limit (UL) of 45 mg per day according to FDA standards. CNS lists a RDA of 20 mg and a UL of 42 mg; MHLW lists a RDA of 10.5 mg and a UL of 50 mg. It has 3 known interactions with other supplements including zinc, vitamin c, calcium. Regular monitoring is strongly recommended when adjusting your intake.
Iron sits in the Trace Minerals category. This page consolidates 5 regional standards, and the limits vary enough that you should not treat one region's rule as universal.
It also has 3 known interactions, so the question is not just the label dose but whether the rest of your stack adds extra risk.
Acute iron overdose is dangerous; chronic excess can damage the liver, heart, and pancreas.
| Region | Organization | RDA | Upper Limit (UL) | Unit |
|---|---|---|---|---|
| πΊπΈ United States | FDA | 18 | 45 | mg |
| πͺπΊ Europe | EFSA | 18 | 45 | mg |
| π¦πΊ Australia | TGA | 18 | 45 | mg |
| π¨π³ China | CNS | 20 | 42 | mg |
| π―π΅ Japan | MHLW | 10.5 | 50 | mg |
RDA = Recommended Daily Allowance (adequate intake for most adults). UL = Tolerable Upper Intake Level (maximum safe daily amount).
Vitamin C enhances iron absorption (positive interaction).
Taking together is beneficial.
Calcium can inhibit iron absorption when taken together.
Take at least 2 hours apart.
First match your product label against the dose table above, then check whether the known interaction list includes anything in your current stack.
If you are taking multiple supplements, the safest approach is usually to audit the whole stack instead of judging a single bottle in isolation.
The safe upper limit (UL) for Iron is 45mg per day according to FDA. Exceeding this amount regularly may increase the risk of adverse effects.
The RDA for Iron is 18mg per day for most adults. This amount is sufficient to meet the needs of 97-98% of healthy individuals.
Yes, Iron has 3 known interactions with other supplements. Iron and zinc compete for absorption.
Check if your supplement stack keeps Iron within safe limits.
Audit My SupplementsDisclaimer: NutriAudit is a decision-support tool designed to help you review your supplement stack for potential duplicate, conflicting, or excessive ingredients. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making changes to your supplement routine, especially if you are pregnant, nursing, taking medications, or have a medical condition.
Based on reference standards from FDA, EFSA, TGA, and MHLW.