Calcium Carbonate and Thyroid Hormone: Drug Interaction Guide

Quick answer: This combination requires caution. Calcium Carbonate and Thyroid Hormone can be used together with adjustments and monitoring.

Interaction severity: Moderate — caution required

How Calcium Carbonate interacts with Thyroid Hormone

Calcium carbonate binds levothyroxine in the gastrointestinal tract, forming insoluble complexes and reducing absorption by 20-25%.

What you should do

Separate administration by at least 4 hours. Monitor TSH after initiating calcium supplements and adjust levothyroxine dose if needed.

Key facts

Severity

Moderate — caution required

Mechanism

Calcium carbonate binds levothyroxine in the gastrointestinal tract, forming insoluble complexes and reducing absorption...

Action

Separate administration by at least 4 hours. Monitor TSH after initiating calcium supplements and adjust levothyroxine d...

Important medical disclaimer: This page provides educational information about drug interactions for general reference. It is not a substitute for professional medical advice, diagnosis, or treatment. Always discuss your specific medications with a qualified healthcare provider before starting, stopping, or changing any treatment. About our editorial team.

Frequently asked questions

Can I take Calcium Carbonate and Thyroid Hormone together?

With caution. Separate administration by at least 4 hours. Monitor TSH after initiating calcium supplements and adjust levothyroxine dose if needed.

What is the severity of this interaction?

The interaction between Calcium Carbonate and Thyroid Hormone is classified as Moderate — caution required. Calcium carbonate binds levothyroxine in the gastrointestinal tract, forming insoluble complexes and reducing absorption by 20-25%.

What should I do if I'm prescribed both?

Separate administration by at least 4 hours. Monitor TSH after initiating calcium supplements and adjust levothyroxine dose if needed. Always consult your prescribing clinician — do not stop or change medications without medical guidance.

Last reviewed: by iMedic Medical Editorial Team. Our editorial process.