Threonine
Threonine is an essential amino acid that the gut uses to build its protective mucus. Adults need about 15 mg per kilogram of body weight a day, 1.05 g for someone weighing 70 kg.
15 mg per kg of body weight a day
1.05 g a day for a 70 kg adult
Upper limit · none set, for lack of studies
- Most per 100 g 1.8g Maitake mushroom
- In protein 23mg/g of protein, the WHO pattern
- Main sources Fish, meat and cheese then eggs, beans and nuts
- Key use Gut mucus its mucin proteins are rich in it
Daily requirement: WHO, FAO and UNU 2007. Food figures per 100 g from USDA FoodData Central, only for foods with a Caltide calorie page.
Foods High in Threonine
Ranked per 100 g, with what a usual portion gives, limited to 3 foods per category. Foods with a Caltide calorie page link to it.
M
Maitake mushroom
1.8g / 100 g
B
Bacon
Nutrition facts
1.7g / 100 g
S
Soy nuts
1.5 g in 1 cup
1.5g / 100 g
P
Pioppini mushroom
1.5g / 100 g
C
Cube steak
0.44 g in 1 piece/slice
1.5g / 100 g
C
Crimini mushroom
1.4g / 100 g
B
Beef roast
0.83 g in 1 regular/thin slice
1.4g / 100 g
B
Beef sirloin steak
0.41 g in 1 piece/slice
1.4g / 100 g
C
Caviar
0.2 g in 1 tablespoon
1.3g / 100 g
T
Turkey mince
0.74 g in 1 patty
1.2g / 100 g
C
Chicken thigh (pan-fried)
0.8 g in 1 medium thigh
1.1g / 100 g
C
Chicken thigh
1.5 g in 1 cup
1.1g / 100 g
What Is Threonine?
Threonine is one of the nine essential amino acids, so it has to come from protein in food or from supplements. It was the last of the essential amino acids to be discovered, in the 1930s, and its side chain carries an alcohol group, which is what gives it its special jobs.
Threonine and the Gut Lining
The inside of the gut is coated with mucus, a gel that keeps bacteria and food particles off the cells beneath it. Its backbone is a family of large proteins called mucins, and long stretches of mucin are made of threonine, serine and proline. Sugar chains attach to those threonines and serines, and the sugars are what make mucus a gel. The gut renews this layer constantly, so it draws on threonine all the time.
How Threonine Switches Proteins On and Off
The same alcohol group is a place where cells attach phosphate groups. Adding or removing a phosphate on a threonine, or on a serine or tyrosine, is one of the most common ways a cell turns an enzyme or a signal on and off. A large family of enzymes, the serine/threonine kinases, does exactly this.
Threonine also shares an oddity with isoleucine: both have two asymmetric carbon atoms, so each can exist in four forms that differ only in their 3D shape, and the body uses only one.
How Much of Each Food Covers Your Daily Threonine
A vegetarian day from the Caltide food library, in usual portions, with one extra column: how many grams of each food alone would give 1.05 g of threonine, the requirement for a 70 kg adult.
| Food | Usual portion | Threonine | For 1.05 g |
|---|---|---|---|
| Egg | 2 eggs (100 g) | 0.6g | 170g |
| Oats | 1 bowl, dry (40 g) | 0.15g | 270g |
| Kidney beans | 1 cup (180 g) | 0.65g | 290g |
| Peas | 1/2 cup (80 g) | 0.16g | 520g |
| Cottage cheese | 1/2 cup (113 g) | 0.56g | 210g |
| Pasta | 1 cup, cooked (140 g) | 0.28g | 520g |
| Mozzarella | 1/2 ball (60 g) | 0.59g | 110g |
| Total | 3g |
The whole day brings about 3 g, 2.9 times the requirement. Threonine is not hard to get from food; what the table shows is that a cup of beans or two eggs gets you more than halfway.
Threonine in Plant Foods
Threonine is not the weak point of plant protein. In the Caltide food library, protein from beans, lentils, chickpeas, nuts, oats and even wheat pasta carries more than the 23 mg per gram the WHO pattern asks for. The amino acid grains run short of is lysine. The full list of foods is in the food library.
Threonine in Supplements
Supplements are a source of threonine as well, though few people take it on purpose.
Supplements That Contain Threonine
- Essential amino acid blendsthe usual place; the label lists threonine per serving
- Protein powderswhey, casein, soy and pea protein all contain it
- L-threoninesold alone as a powder or capsules, but rarely
What to Know About Threonine Supplements
There is no good evidence that extra threonine helps healthy people who already meet the requirement, and no upper limit has been set because studies are lacking. If a blend lists threonine, add it to your log by the amount on the label.
Sources are listed at the end of this page. Not medical advice.
Tracking Threonine in Caltide
- Logged automaticallyCaltide adds up the threonine in every food you log and the supplements you tick off, and once your weight is set shows it in the Nutrition tab against 15 mg per kilogram of body weight.
Threonine Sources and References
The figures and claims on this page are checked against these sources. Food amounts come from USDA FoodData Central.
Questions About Threonine
About 15 mg per kilogram of body weight, according to the WHO, FAO and UNU 2007 report: 1.05 g a day for a 70 kg adult, or 23 mg per gram of protein.
In the Caltide food library, maitake mushroom: 1.8 g per 100 g. Bacon (1.7 g) and Soy nuts (1.5 g) come next.
It is built into proteins, and it is one of the main amino acids in mucins, the proteins that make the mucus lining the gut. Threonine in proteins is also one of the spots where cells attach phosphate groups to switch proteins on and off.
No. Cod has 1 g per 100 g, so one 100 g piece covers about what a 70 kg adult needs in a day. Kidney beans have 0.36 g and eggs 0.6 g.
Healthy people eating enough protein do not. Threonine is mostly sold inside essential amino acid blends, and there is no good evidence that extra threonine helps people who already meet the requirement.
Yes. Beans, lentils, chickpeas, nuts, seeds and oats all carry it, and their protein meets the WHO pattern of 23 mg per gram of protein.
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