Calcium and Levothyroxine: I've heard that I must... - Thyroid UK

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Calcium and Levothyroxine

PillJunkie profile image
15 Replies

I've heard that I must not have any Calcium intake four hours before and after taking Levothyroxine, as the calcium absorbs the drug, lessening its effectiveness. Has anybody else heard of this?

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PillJunkie
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15 Replies
SlowDragon profile image
SlowDragonAdministrator

That’s correct

Levothyroxine is an extremely fussy hormone and should always be taken on an empty stomach and then nothing apart from water for at least an hour after

No other medication or supplements at same as Levothyroxine, leave at least 2 hour gap.

Some like iron, calcium, magnesium, HRT, omeprazole or vitamin D should be four hours away

(Time gap doesn't apply to Vitamin D mouth spray)

Why are you taking calcium. Have you had calcium levels checked

You are on High dose vitamin D, this will increase calcium levels

Many people take Levothyroxine soon after waking, but it may be more convenient and perhaps more effective taken at bedtime

verywellhealth.com/best-tim...

PillJunkie profile image
PillJunkie in reply toSlowDragon

Thank you, SlowDragon for another helpful answer. I'm struggling with the practicalities of this, though. If I take Levo first thing, I simply cannot leave a gap of two hours before I take my other meds. My anxiety and depression demands that I take those meds as soon as I wake. Taking Levo two hours later would just not be practical either, as you can imagine.

I can't take Levo two hours before I retire because my stomach would not be empty. If, on the other hand, I take my night time meds two hours before I retire then, being sedatives, they may not get me through the night (and this is probably impractical anyway).

I'm sure I must not be alone with this quandary. What is my best compromise, do you think?

SlowDragon profile image
SlowDragonAdministrator

See point 8 towards bottom of this web page

nhs.uk/medicines/levothyrox...

Is there any food or drink I need to avoid?

are some foods and drinks that do not mix well with levothyroxine:

drinks containing caffeine, like coffee, tea and some fizzy drinks, can reduce the amount of levothyroxine your body takes in. Leave at least 30 minutes after taking levothyroxine before you drink them.

calcium-rich foods, such as milk, cheese, yoghurt and broccoli, can reduce the amount of levothyroxine your body takes in. Leave at least 4 hours between taking levothyroxine and eating calcium-rich foods.

PillJunkie profile image
PillJunkie in reply toSlowDragon

I think, therefore, taking Levo in the morning is ruled out. I can't go four hours without a white tea or coffee, or my porridge. In any case, I work two days a week. I'll just have to take Levo at night at the same time as my other meds (Pregabalin & Quetiapine).

RedApple profile image
RedAppleAdministrator

Calcium taken too close to the time you take your levothyroxine can block absorption of the levothyroxine. If you look at the PIL (patient information leaflet) that comes with your levothyroxine, you may find that calcium is listed along with other things, as something that can affect the way your levothyroxine works.

I'm not sure if there is an absolutely specific length of time proven, but leaving a two hour minimum gap between taking levo and taking calcium is typically suggested.

PillJunkie profile image
PillJunkie in reply toRedApple

Thank you, RedApple. No, it isn't listed on the PIL; I only heard about this by chance. My endo is quite happy for me to take it with anything!

greygoose profile image
greygoose

We're talking about calcium supplements here with the four hour gap, because calcium will bind to thyroid hormones and make them unabsorbably. The little drop of milk you have in your tea or coffee - or even on your cornflakes, won't make must difference because the amount of calcium would be so small. :)

RedApple profile image
RedAppleAdministrator in reply togreygoose

On the other hand, if you have cheese on toast for breakfast, and take your levo too close to that, it might make a difference 😊 I think four hours gap for calcium in everyday foods is excessive though.

greygoose profile image
greygoose in reply toRedApple

How much cheese do you put on your toast??? lol I don't think my version of cheese on toast would affect my levo.

RedApple profile image
RedAppleAdministrator in reply togreygoose

🤣 Commercially made bread often has added calcium too I think.

greygoose profile image
greygoose in reply toRedApple

Even so... I can't see that it's going to make that much difference. And, if you have the same breakfast every day - as I do, I have to admit - although not cheese on toast! - your dose will be adjusted to it. If it's just from time to time it's not going to make much difference. Pretty sure that it's calcium supplements they're talking about when they talk about a four-hour gap. I means, we shouldn't get obsessive about these things. :)

PillJunkie profile image
PillJunkie in reply togreygoose

That's very reassuring, greygoose, thank you.

greygoose profile image
greygoose in reply toPillJunkie

You're welcome. :)

Sleeplessinlife profile image
Sleeplessinlife

I only found out by accident that I'm not supposed to take calcium supplements until 4hrs after levothyroxine, who reads the patient/meds notes in depth! Me...but not my sister, who says she just swallow her meds all together. I'm not enjoying the calcium supplement anyway, constipation!.. meds are a minefield of side effects..enough to put you off

RedApple profile image
RedAppleAdministrator in reply toSleeplessinlife

'who reads the patient/meds notes in depth! '

Most medics don't either! Whenever I've asked a GP anything about medications, I've been told to ask a pharamcist. But if you don't know something might be a problem in the first place, you wouldn't know to ask anyway. 🙄

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