Can I take Levothyroxine and Calcium together?

Why this happens

Calcium binds to the levothyroxine in your stomach, creating a large 'clump' that is too big for your body to absorb into the bloodstream. This means the medicine passes through your system without being used.

You should separate these two by at least 4 hours. It is usually best to take your levothyroxine first thing in the morning on an empty stomach, and wait until lunch or dinner to take any calcium supplements or eat large amounts of dairy.

Drug-drug interaction

You must take levothyroxine and calcium at least 4 hours apart. Calcium supplements significantly reduce the absorption of levothyroxine, which can make your thyroid treatment ineffective.

Caffeine (Coffee/Tea)

Coffee can significantly reduce the absorption of levothyroxine. You should wait at least 30 to 60 minutes after taking your tablet before drinking coffee or tea.

Dairy products (Milk/Yoghurt)

Calcium found in dairy products can bind to levothyroxine and prevent it from being absorbed properly. Avoid consuming dairy at the same time as your medication; leave a gap of at least 4 hours.

Soya

Soya can interfere with how levothyroxine is absorbed. If you eat a diet high in soya, you may need a different dose of medication. Consult your doctor before making major changes to your soya intake.

Papaya

There is some evidence that papaya can interfere with the absorption of levothyroxine. It is best to avoid eating large amounts of papaya close to the time you take your dose.

High-fibre foods

A very high-fibre diet (such as bran or certain cereals) can reduce the absorption of levothyroxine. Try to keep your fibre intake consistent and discuss any major dietary changes with your doctor.

Spinach, Rhubarb, and Beetroot (Oxalates)

These foods are high in oxalic acid, which can bind to calcium and prevent it from being absorbed. Avoid eating large amounts of these foods at the same time as taking your calcium supplement.

Whole-grain cereals (Phytic acid)

Foods high in phytic acid, such as 100% wheat bran or whole grains, can reduce the absorption of calcium if eaten at the same time.

Taking 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.