Altered intestinal absorption of L-thyroxine caused by coffee.

  title={Altered intestinal absorption of L-thyroxine caused by coffee.},
  author={Salvatore Benvenga and Luigi Bartolone and Maria Angela Pappalardo and Antonia Russo and Daniela Lapa and Grazia Maria Giorgianni and Giovanna Saraceno and Francesco Trimarchi},
  journal={Thyroid : official journal of the American Thyroid Association},
  volume={18 3},
OBJECTIVE To report eight case histories, and in vivo and in vitro studies showing coffee's potential to impair thyroxine (T4) intestinal absorption. DESIGN Of eight women with inappropriately high or nonsuppressed thyroid-stimulating hormone (TSH) when T4 was swallowed with coffee/espresso, six consented to the evaluation of their T4 intestinal absorption. This in vivo test was also administered to nine volunteers. In three separate tests, two 100 microg T4 tablets were swallowed with coffee… 

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