Can I take Liothyronine and Vitamin d together?
Drug interaction guide
Originally published 12 May 2026
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There is no direct harmful interaction between liothyronine and vitamin D. In fact, vitamin D is often necessary for thyroid hormones to work effectively in your body's cells. However, if your vitamin D supplement also contains calcium, the calcium can interfere with how well your body absorbs the thyroid medication.
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Why this happens
Vitamin D itself does not change how liothyronine is processed. However, many vitamin D supplements are combined with calcium. Calcium carbonate or calcium citrate can bind to thyroid hormones in the digestive tract, preventing them from entering the bloodstream.
What you should do
Back to contentsYou can safely take both, but if your vitamin D supplement contains calcium, you must space them apart. Take your liothyronine on an empty stomach, at least 4 hours before or after taking any supplement containing calcium. If your vitamin D is a pure oil-based capsule or drop without added minerals, they can be taken closer together, but it is still best practice to take thyroid medication alone with water.
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Using other medicines
Back to contentsTaking multiple medicines? Our Medicines Interaction Checker helps you check whether your prescriptions, over-the-counter medicines, and supplements are safe to take together. Simply search for your medicines to see potential interactions and what to do about them.
Disclaimer
This information is for general educational purposes only and should not be relied upon as a substitute for professional medical advice. Always consult your GP, pharmacist, or another qualified healthcare professional before making decisions about your medications. Individual circumstances may vary, and only a healthcare professional who knows your medical history can provide personalised guidance.
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Article history
The information on this page is written and peer reviewed by qualified clinicians.
12 May 2026 | Originally published
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