Threonine
Also known as L-threonine, Thr
Threonine is an essential amino acid that the body cannot make, so it must come from food. It helps build proteins and is especially concentrated in collagen, elastin, and the mucus that protects the gut lining.
Why it matters
What it does in your body
- Protein building block
- Component of collagen and elastin for skin and connective tissue
- Supports gut mucus barrier and digestion
- Contributes to immune antibody production
Intake guidance
How much you need
The IOM sets the requirement at 20 mg/kg/day, about 1.4 g/day for a 70 kg adult. Any diet with enough total protein provides plenty.
What affects it
What affects your intake
Total protein intake
Meeting protein needs covers threonine, which is well distributed across animal and plant proteins.
Gut and immune demand
The gut lining uses a lot of threonine for mucus, so needs can rise with digestive stress, though diet still keeps pace.
Protein quality
Complete proteins such as meat, dairy, eggs, and soy supply threonine reliably.
In practice
Good to know
Deficiency is very rare in people eating a normal diet. Threonine matters for connective tissue and the intestinal mucus barrier, and it is a common ingredient in animal feed, but human supplementation is not needed for the general population. Food provides ample amounts.
Where to get it
Best food sources
The bottom line
Eat enough total protein and threonine takes care of itself. There is no routine reason to supplement it.
Track threonine automatically
Threonine is one of the 92 nutrients Vora reads from a photo of your meal, so you can see where you stand without weighing or logging by hand.
Sources and method
The classification, roles, and guidance on this page come from the references below, drawing on the Institute of Medicine (now the National Academies) Dietary Reference Intakes and reputable nutrition science.
- Institute of Medicine (2005), Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids
This page is for general education, not medical advice. Reference intakes are population averages for healthy people and do not replace guidance from your doctor or a registered dietitian, especially if you are pregnant, managing a health condition, or considering supplements.