Thyroid Hormone absorption interference

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Thyroid Hormone absorption interferenceJacob Schor ND FABNOSeptember 9, 2008Coffee has been added to the list of things that interfere with absorption of thyroid hormone. The list of things that you shouldn’t take along with thyroid hormone keeps growing. Most simply hinder absorption of the drug from the digestive tract and effectively reduce the dose that gets into your blood. This isn’t a big problem is you only eat these foods rarely; if for one day you don’t absorb all of your thyroid dose, it’s not a big deal. If you eat the same foods every single day, it’s also not a big deal because you’ll adjust the amount of medicine you take to a slightly higher dose and compensate. The problem shows up with food or other medications that people will start to take regularly. This can throw of your dose requirements.Take coffee. This may be a problem for many people with hypothyroid function who are taking replacement hormone. If these people are under treated they feel really tired. If they are also vitamin B-12 deficient, the feel really, really tired. Tired people drink coffee. According to a paper published this past March, coffee decreased the amount of thyroid hormone absorption by about a third. Instead of tired, these people will start to feel exhausted. So, they drink more coffee and they absorb even less of their hormone dose. It’s a vicious cycle. The trick is to take thyroid hormone first thing in the morning on an empty stomach, at least 30 minutes before eating anything. Coffee isn’t the first thing discovered to interfere with thyroid hormone. Back in 1992 both aluminum hydroxide antacids and the iron supplement ferrous sulfate were reported to interfere. In 2000 a report in JAMA added calcium carbonate to the list. Soy protein shakes were added in 2001. The drug Raloxifene was added in 2003. Then chromium picolinate in 2007. And now, coffee.Some patients just lie and tell their doctors that they took their medicine when they didn’t. But not our patients. There are some foods, namely cabbage that are well known to decrease thyroid hormone production and cause goiters if eaten in large enough quantities, but that’s not what I’m writing about here.Thus the general direction given to all patients taking supplemental thyroid hormone to always take it alone without food or other medication. You just don’t know what’s going to mess things up.When a patient who is taking thyroid hormone does well initially and then it seems the drug stops working, the first thing to rule out is interference from something else they are taking.A 2007 paper tells us that taking thyroid hormone at bedtime works much better than taking it in the morning. For some reason the hormone is better absorbed at night and reaches greater blood concentrations than when taken in the morning. [i confess that I just read this for the first time and haven't tried it with anyone as of this writing. ]REFERENCES: Thyroid. 2008 Mar;18(3):293-301.Click here to read Links Altered intestinal absorption of L-thyroxine caused by coffee. Benvenga S, Bartolone L, Pappalardo MA, Russo A, Lapa D, Giorgianni G, Saraceno G, Trimarchi F.