Effects of pharmacological fiber supplements on levothyroxine absorption
Chiu AC, Sherman SI
Published in Thyroid, Vol. 8 (8), pp. 667-71
Methodology
Within-subject study in 8 volunteers: 600 mcg levothyroxine taken alone, with 1,000 mg calcium polycarbophil, or with 3.4 g psyllium, 4 weeks apart.
Key Findings
Levothyroxine absorption was 89% alone, 86% with polycarbophil and 80% with psyllium, with overlapping confidence intervals; peak was later with psyllium.
Conclusions
Neither fiber supplement was likely to cause detectable levothyroxine malabsorption.
Limitations
Only 8 healthy volunteers, single doses; cannot rule out a smaller effect over long-term use.
Supplements Studied
neither calcium polycarbophil nor psyllium hydrophilic mucilloid are likely to cause malabsorption of LT4
neither calcium polycarbophil nor psyllium hydrophilic mucilloid are likely to cause malabsorption of LT4
Study Details
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This information is for educational purposes only. Always consult a healthcare professional before starting any supplement regimen.