Levothyroxine Food Interactions: What to Eat and Avoid for Better Absorption

When you take levothyroxine, a synthetic thyroid hormone used to treat hypothyroidism. Also known as Synthroid, it’s meant to replace what your thyroid can’t make. But if you eat or drink the wrong things around your dose, it won’t absorb properly—leaving you tired, gaining weight, or feeling worse than before.

That’s where calcium, a mineral found in dairy, fortified juices, and supplements comes in. Calcium binds to levothyroxine in your gut and stops it from entering your bloodstream. Same with iron, often taken for anemia or pregnancy. Even coffee, a daily habit for millions—yes, even black coffee—can cut absorption by up to 30%. And soy, fiber-rich foods, and antacids? They’re all on the no-go list within hours of your dose.

You don’t have to give up these things forever. You just need to space them out. Take levothyroxine on an empty stomach, at least 30 to 60 minutes before breakfast. Wait four hours before taking calcium, iron, or multivitamins. Drink your coffee after lunch. Simple? Yes. Easy to forget? Also yes. But getting this right means your thyroid levels stabilize, your energy returns, and you stop guessing why you still feel exhausted.

The posts below show real cases—like how calcium-fortified orange juice sabotages thyroid meds, why some people need to time their supplements down to the minute, and what happens when people skip the rules. These aren’t theoretical warnings. They’re stories from people who learned the hard way. You don’t have to be one of them.