AUTHOR=Ferrari Silvia Martina , Patrizio Armando , Mazzi Valeria , Ragusa Francesca , Botrini Chiara , Elia Giusy , Balestri Eugenia , Barozzi Emilio , Rugani Licia , Bracchitta Fabiana , Stoppini Giulio , Frenzilli Giada , Baldini Enke , Virili Camilla , Benvenga Salvatore , Fallahi Poupak , Antonelli Alessandro TITLE=Lactose intolerance and levothyroxine malabsorption: a review of the literature and report of a series of patients treated with liquid L-T4 without lactose JOURNAL=Frontiers in Endocrinology VOLUME=15 YEAR=2024 URL=https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2024.1386510 DOI=10.3389/fendo.2024.1386510 ISSN=1664-2392 ABSTRACT=

In hypothyroid patients needing large doses of levothyroxine (L-T4) (>1.7–2 μg/kg/day) to reach euthyroidism, lactose intolerance (LI) needs to be excluded, owing to the high prevalence in the population. If LI is present, a lactose-free diet decreases the rate of L-T4 malabsorption. However, an increased requirement of L-T4 is described in patients with LI, which can be beneficially treated using lactose-free L-T4 formulation. The lactose-free liquid L-T4 formulation is able to circumvent LI malabsorption leading to the normalization of thyroid-stimulating hormone (TSH) in patients with subclinical hypothyroidism and long-term stable TSH levels.