Can I Take Iron and Calcium Together? Timing & Dosage Guide

Iron and Calcium have a moderate interaction. See interaction data, 5-regional dosage standards (FDA/EFSA/TGA/CNS/MHLW), and expert recommendations.

Quick Answer

Calcium can inhibit iron absorption when taken together.

Recommendation: Take at least 2 hours apart.

iron + calcium

Moderateabsorption inhibition

Calcium can inhibit iron absorption when taken together.

Tip: Take at least 2 hours apart.

Safe Dosage Comparison (5 Regional Standards)

Standardironcalcium
US (FDA)18 / 45 mg
(RDA/UL)
1000 / 2500 mg
(RDA/UL)
EU (EFSA)18 / 45 mg
(RDA/UL)
1000 / 2500 mg
(RDA/UL)
AU (TGA)18 / 45 mg
(RDA/UL)
1000 / 2500 mg
(RDA/UL)
CN (CNS)20 / 42 mg
(RDA/UL)
800 / 2000 mg
(RDA/UL)
JP (MHLW)10.5 / 50 mg
(RDA/UL)
800 / 2300 mg
(RDA/UL)

Values shown as RDA (Recommended Dietary Allowance) / UL (Tolerable Upper Intake Level). Sources: NIH, FDA, EFSA, FSANZ, CNS, MHLW.

Frequently Asked Questions

Can I take iron and calcium together?

Use caution. Calcium can inhibit iron absorption when taken together. Take at least 2 hours apart.

How should I take iron and calcium?

Take at least 2 hours apart. The severity of this interaction is considered medium. If you have concerns, consult your healthcare provider.

Taking More Supplements?

This page only checks one pair. Use NutriAudit to check your full supplement stack for interactions, duplicates, and safe dosages.

Not medical advice. Always consult a qualified healthcare professional for personal medical decisions.