L-Threonine Side Effects

L-Threonine is a crystalline powder that has a slightly sweet taste. It is an amino acid that is often used as a nutrition intensifier in foods and dietary supplements. Though it’s considered safe, some are convinced it has potentially dangerous health effects.

What Is L-Threonine?

L-Threonine (T or Thr) is an amino acid, or a molecule that is one of the building blocks of proteins. It is an essential amino acid, meaning that it can’t be made by the body and therefore must be acquired through the diet. Many different foods contain threonine, including most meats, chicken, cottage cheese, mushrooms, and some leafy vegetables. This amino acid supports many different body functions. Threonine is required for the formation of healthy bones and teeth and plays a role in the immune system because it is a necessary constituent of antibodies. It is also present in large amounts in muscle and connective tissues. It is thought to help contribute to their strength and elasticity due to its high proportion in collagen and elastin. Finally, it is required for the synthesis of certain neurotransmitters, suggesting a role in neural health. It is well known that threonine is a necessary building block of many proteins, but its actual role in metabolism is not as well known. This amino acid can be converted to pyruvate or to alpha-ketobutyrate and eventually to succinyl-CoA, suggesting an association with the citric acid cycle. It is one of the amino acids that can be phosphorylated, which is a major mechanism by which cells control various signaling pathways. In addition, it is required for the body to synthesize two non-essential amino acids, glycine and serine, both of which play important roles in various physiological functions.

Possible Side Effects of L-Threonine

Although L-Threonine generally regarded as a very safe and effective supplement, there can be some minor side effects. The side effects may:

  • L-Threonine is not as well researched as many other amino acids, and its overall functionality as part of animal protein is vague.  Side effects are as yet unknown, though it is not believed that there is a level of toxicity or an apparent capability of overdose.

GRAS Affirmation: Yes

Generally recognized as safe (GRAS) is an American Food and Drug Administration (FDA) designation that a chemical or substance added to food is considered safe by experts, and so is exempted from the usual Federal Food, Drug, and Cosmetic Act (FFDCA) food additive tolerance requirements. L-Threonine is considered safe.

Suggested Dosage


Special Populations Precaution

There is a lot of concern about diet and nutrition for these population, like Newborns, children, pregnant, sensitive to L-Threonine populations. Better consult to your doctor if you would like to intake L-Threonine.




Related Research

1. Spectral characterization of some second harmonic generation materials from the amino acid family: L-Threonine and L-prolinium tartrate. [Spectrochim Acta A Mol Biomol Spectrosc. 2014 Aug 14] Author: Moovendaran K, Natarajan S.

2. Modification of glycolysis and its effect on the production of L-threonine in Escherichia coli. [J Ind Microbiol Biotechnol. 2014 Jun] Author: Xie X, Liang Y, Liu H, Liu Y, Xu Q, Zhang C, Chen N.

3. Identification and characterization of protein encoded by orf382 as L-threonine dehydrogenase. [J Microbiol Biotechnol. 2014 Jun 28] Author: Ma F, Wang T, Ma X, Wang P.

4. A QM/MM study of the L-threonine formation reaction of threonine synthase: implications into the mechanism of the reaction specificity. [J Am Chem Soc. 2014 Mar 26] Author: Shoji M, Hanaoka K, Ujiie Y, Tanaka W, Kondo D, Umeda H, Kamoshida Y, Kayanuma M, Kamiya K, Shiraishi K, Machida Y, Murakawa T, Hayashi H.

5. Binding of NAD+ and L-threonine induces stepwise structural and flexibility changes in Cupriavidus necator L-threonine dehydrogenase. [J Biol Chem. 2014 Apr 11] Author: Nakano S, Okazaki S, Tokiwa H, Asano Y.

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