Can you take calcium or iron with levothyroxine?
Also searched as: thyroid medication, Levoxyl, Tums, multivitamin
Short answer
Yes, but not at the same time. Calcium and iron can block levothyroxine from being absorbed. Separating them by at least 4 hours usually solves it.
Why it happens
Calcium, iron and some antacids bind to levothyroxine in the gut, so less of your thyroid medicine gets into your body. Over time your thyroid levels can drift.
What to do
- Take levothyroxine on an empty stomach, as directed.
- Take calcium, iron, antacids or multivitamins at least 4 hours apart from it.
- Tell your prescriber if you start or stop these supplements, since your dose may need checking.
Signs to watch for
- Tiredness, feeling cold or weight gain (signs your dose may be too low)
If symptoms are severe, call 911 or go to the nearest emergency room.
Sources
Last reviewed November 4, 2026. For education only, not medical advice. Talk to your pharmacist or prescriber before changing anything.
