> ## Documentation Index
> Fetch the complete documentation index at: https://markers.iollo.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Thyroid stimulating hormone (TSH)

Thyroid stimulating hormone (TSH) is produced by the pituitary gland and regulates the production of thyroid hormones. High or low levels of TSH can indicate thyroid dysfunction.

## iollo markers that associate with Thyroid stimulating hormone (TSH)

### Carnitine

Thyroid hormones increase carnitine excretion. Low thyroid function and high TSH may increase carnitine retention.

<Accordion title="References">
  Salvatore Benvenga, Rosaria M. Ruggeri, Antonia Russo, Daniela Lapa, Alfredo Campenni, Francesco Trimarchi. Usefulness of l-Carnitine, A Naturally Occurring Peripheral Antagonist of Thyroid Hormone Action, in Iatrogenic Hyperthyroidism: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial. *The Journal of Clinical Endocrinology & Metabolism* (2001). [https://doi.org/10.1210/jcem.86.8.7747](https://doi.org/10.1210/jcem.86.8.7747)

  M. A. R. D. Santos, M. A. R. Ferreira, C. A. R. Santos, et al.. Thyroid hormones and carnitine in the second trimester negatively affect fetal growth in the setting of severe early-onset intrauterine growth restriction. *Frontiers in Endocrinology* (2023). [https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2023.1080969/full](https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2023.1080969/full)

  Salvatore Benvenga, Rosaria M. Ruggeri, Antonia Russo, et al.. Thyroid hormones increase carnitine excretion: a true situation of secondary carnitine deficiency. *The Journal of Clinical Endocrinology & Metabolism* (2001). [https://academic.oup.com/jcem/article/86/8/3579/2848640](https://academic.oup.com/jcem/article/86/8/3579/2848640)
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### Phenylalanine

Phenylalanine is converted to tyrosine, the precursor for thyroid hormones. Phenylalanine deficiency can reduce tyrosine and increase TSH.

<Accordion title="References">
  Katie Wilkinson, Kimberly Langdon M.D.. L-Tyrosine and Hypothyroidism - Paloma Health. *Paloma Health* (2024). [https://www.palomahealth.com/supplements/l-tyrosine-hypothyroidism](https://www.palomahealth.com/supplements/l-tyrosine-hypothyroidism)

  Unnamed. The many faces of thyroxine - PMC - NCBI. *NCBI* (2020). [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7242060/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7242060/)

  Unnamed. Thyroid hormone | biochemistry - Britannica. *Britannica* (2024). [https://www.britannica.com/science/thyroid-hormone](https://www.britannica.com/science/thyroid-hormone)

  Hari Krishnamurthy, Karthik Krishna, Tianhao Wang, John J. Rajasekaran, Karenah Rajasekaran, Vasanth Jayaraman, Swarnkumar Reddy, Xiaorong Song, and Vijay R. Rajasekaran. Effect of Micronutrients on Thyroid Parameters - PMC - NCBI. *NCBI* (2021). [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8820928/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8820928/)
</Accordion>

### Taurine

Taurine supports normal thyroid function. Low taurine is associated with hypothyroidism and elevated TSH levels.

<Accordion title="References">
  Baskin, S.I., Klekotka, S.J., Kendrick, Z.V.. Correlation of platelet taurine levels with thyroid function. *Journal of Endocrinological Investigation* (1979). [https://doi.org/10.1007/BF03350410](https://doi.org/10.1007/BF03350410)

  Parminder Singh, et al.. Taurine dietary supplementation attenuates brain, thyroid, testicular .... *Journal of Functional Foods* (2017). [https://www.sciencedirect.com/science/article/pii/S2314853517300720](https://www.sciencedirect.com/science/article/pii/S2314853517300720)
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### Tyrosine

Tyrosine is the precursor for thyroid hormone synthesis. Low tyrosine availability can impair thyroid function and increase TSH levels.

<Accordion title="References">
  Tariq MA, Jialal I. Physiology, Thyroid Stimulating Hormone - StatPearls - NCBI. *StatPearls* (2024). [https://www.ncbi.nlm.nih.gov/books/NBK499850/](https://www.ncbi.nlm.nih.gov/books/NBK499850/)

  Coupling reaction: TPO combines iodinated tyrosine residues to make triiodothyronine (T3) and tetraiodothyronine (T4). MIT and DIT join to form.... Physiology, Thyroid Hormone - StatPearls - NCBI Bookshelf. *StatPearls* (2023). [https://www.ncbi.nlm.nih.gov/books/NBK500006/](https://www.ncbi.nlm.nih.gov/books/NBK500006/)
</Accordion>