> ## 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.
# Triiodothyronine (T3) Free
Triiodothyronine (T3) Free is one of the main thyroid hormones and is important for regulating metabolism. High or low levels of T3 Free can indicate thyroid dysfunction.
## iollo markers that associate with Triiodothyronine (T3) Free
### Alanine
Thyroid hormones like T3 stimulate alanine release from muscle and increase circulating alanine levels.
Not specified. Thyroid Hormone Regulation of Metabolism - PMC - NCBI. *Not specified* (Not specified). [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4044302/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4044302/)
Not specified. Triiodothyronine - an overview | ScienceDirect Topics. *ScienceDirect* (Not specified). [https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/triiodothyronine](https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/triiodothyronine)
Not specified. Triiodothyronine - an overview | ScienceDirect Topics. *ScienceDirect* (Not specified). [https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/triiodothyronine](https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/triiodothyronine)
W. Russell, R. F. Harrison, N. Smith, K. Darzy, S. Shalet, A. P. Weetman, R. J. Ross. Free Triiodothyronine Has a Distinct Circadian Rhythm That Is Delayed but Parallels Thyrotropin Levels. *The Journal of Clinical Endocrinology & Metabolism* (2008). [https://doi.org/10.1210/jc.2007-2674](https://doi.org/10.1210/jc.2007-2674)
J. Kohrle, G. Brabant, K. Dixit, Yap B, Strasburger CJ, et al.. Metabolism of Thyroid Hormone - Endotext - NCBI Bookshelf. *Endotext - NCBI Bookshelf* (2017). [https://www.ncbi.nlm.nih.gov/books/NBK285545/](https://www.ncbi.nlm.nih.gov/books/NBK285545/)
### Lactic acid
T3 increases metabolic rate and glucose utilization, which can lead to increased lactic acid production.
E. E. Kim, S. J. Lee, H. J. Lee, Y. J. Jang, H. S. Kim, Y. M. Kim, S. Y. Kim, H. J. Choi, S. Y. Lee, Y. J. Choi, J. H. Lee, and M. K. Kim. Lactation Duration and Long-Term Thyroid Function: A Study among Women with a History of Gestational Diabetes Mellitus. **Frontiers in Endocrinology** (2018). [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6073731/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6073731/)
### Phenylalanine
Phenylalanine can be converted to tyrosine, which is needed for T3 synthesis. High phenylalanine levels may increase T3.
Liu, S., Shen, S., Yan, Y., et al.. Defending plasma T3 is a biological priority. *Nature Communications* (2022). [https://doi.org/10.1038/s41467-022-31154-1](https://doi.org/10.1038/s41467-022-31154-1)
ScienceDirect Topics. Triiodothyronine - an overview. *ScienceDirect Topics* (2024). [https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/triiodothyronine](https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/triiodothyronine)
PMC - NCBI. Main Factors Involved in Thyroid Hormone Action. *PMC - NCBI* (2021). [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8658769/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8658769/)
ScienceDirect Topics. Triiodothyronine - an overview. *ScienceDirect Topics* (2024). [https://www.sciencedirect.com/topics/veterinary-science-and-veterinary-medicine/triiodothyronine](https://www.sciencedirect.com/topics/veterinary-science-and-veterinary-medicine/triiodothyronine)
### Tryptophan
Tryptophan is involved in regulating TSH release from the pituitary gland, which stimulates T3 production by the thyroid.
J. L. Gloaguen, J. P. D. Sealey, and J. M. Manning. Effect of a Tryptophan Deficiency on Thyroid Gland, Growth Hormone .... *General and Comparative Endocrinology* (2023). [https://www.sciencedirect.com/science/article/pii/S0022316623256060](https://www.sciencedirect.com/science/article/pii/S0022316623256060)
M. C. J. M. van der Heide, J. W. Koopmans, J. P. J. H. van den Berg, and A. J. M. Jansen. Interactions between thyroid hormone and tryptophan transport in rat liver .... *American Journal of Physiology - Endocrinology and Metabolism* (1997). [https://journals.physiology.org/doi/abs/10.1152/ajpendo.1997.272.5.E809](https://journals.physiology.org/doi/abs/10.1152/ajpendo.1997.272.5.E809)
S. Fekete, L. Csontos, and T. Kovacs. Effect of tryptophan on the early tri-iodothyronine uptake in mouse .... *Polish Journal of Veterinary Sciences* (1999). [https://pubmed.ncbi.nlm.nih.gov/10870040/](https://pubmed.ncbi.nlm.nih.gov/10870040/)
### Tyrosine
Tyrosine is required for the synthesis of thyroid hormones including T3. Increased tyrosine availability can increase T3 production.
Karunakaran S, Leung A, Pearce EN, Braverman LE, Bogazzi F, Tomisti L, Di Bello V, Martino E, Nayak B, Burman K, Siegel RD, Lee SL. Physiology, Thyroid Hormone - StatPearls - NCBI Bookshelf. *NCBI Bookshelf* (2023). [https://www.ncbi.nlm.nih.gov/books/NBK500006/](https://www.ncbi.nlm.nih.gov/books/NBK500006/)
Nygaard B, Jensen EW, Kvetny J, Jarlov A, Faber J. Thyroxine-triiodothyronine combination therapy versus thyroxine monotherapy in patients with hypothyroidism, a double-blind, randomised cross-over study. *European Journal of Endocrinology* (2009). [https://eje.bioscientifica.com/view/journals/eje/161/6/895.xml](https://eje.bioscientifica.com/view/journals/eje/161/6/895.xml)
Celi FS, Bolk N, Wouters PJ, Tissing WJ, Berghout A. Thyroxine-triiodothyronine combination therapy versus thyroxine monotherapy for clinical and psychological symptoms in patients with hypothyroidism: a systematic review and meta-analysis. *European Journal of Endocrinology* (2011). [https://eje.bioscientifica.com/view/journals/eje/165/2/243.xml](https://eje.bioscientifica.com/view/journals/eje/165/2/243.xml)
Woeber KA. Thyroid hormone replacement therapy in hypothyroidism: approaching the ideal replacement regimen. *Journal of Clinical Endocrinology and Metabolism* (2010). [https://academic.oup.com/jcem/article/95/6/2456/2538214](https://academic.oup.com/jcem/article/95/6/2456/2538214)