Coffee interferes with the intestinal absorption of levothyroxine

[jimh111]

I've posted on this before referring to the original study but I've come across this review thyroid.org/wp-content/uplo... which is excellent and much easier to follow with nice graphs. If we observe the blue columns ('AUC') which represent the 'area under the curve', i.e. how much levo has been absorbed, we can see that coffee reduces levothyroxine absorption by about a third. If you have the coffee an hour later it has no effect.

The study also has some great news! Bran has even worse effects on levothyroxine than coffee. As far as I know expensive chocolates have no effect but they are good for the heart.

Figure 3 shows that antacids should also be avoided at the time of taking levothyroxine. That's something most of us know already.

[SilverAvocado]

Interesting, thanks for posting! I'm glad they tried at least one different food. A friend of a friend was told she could take her Levothyroxine with any food except milk and coffee! I assume because they are two foods that have specifically been demonstrated to interfere with absorption.

A shame the bran and antacid were tried with just 2 and 1 participant respectively. The antacid really floors absorption, and makes me wonder how close some of us might be to having acid this low when we are very hypothyroid. One possible explanation for why some posters are taking large doses but not getting much increase in blood test numbers.

[Treepie]

I always take levo at bed time or middle of night hours away from coffee.

[Catseyes235]

Interesting but rather limited study with only 8 female subjects. Calcium and therefore milk in cereal etc has also been implicated in uptake so I just try and leave an hour gap between taking pill and eating or drinking anything but water. Not too difficult but hard if going out early.