Frontiers in Endocrinology (Apr 2024)

Lactose intolerance and levothyroxine malabsorption: a review of the literature and report of a series of patients treated with liquid L-T4 without lactose

  • Silvia Martina Ferrari,
  • Armando Patrizio,
  • Valeria Mazzi,
  • Francesca Ragusa,
  • Chiara Botrini,
  • Giusy Elia,
  • Eugenia Balestri,
  • Emilio Barozzi,
  • Licia Rugani,
  • Fabiana Bracchitta,
  • Giulio Stoppini,
  • Giada Frenzilli,
  • Enke Baldini,
  • Camilla Virili,
  • Salvatore Benvenga,
  • Salvatore Benvenga,
  • Salvatore Benvenga,
  • Poupak Fallahi,
  • Alessandro Antonelli

DOI
https://doi.org/10.3389/fendo.2024.1386510
Journal volume & issue
Vol. 15

Abstract

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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.

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