🔑 Core Function

• Structural protein synthesis: Critical for collagen, elastin, and tooth enamel.
• ️ Immune function: Involved in antibody and immunoglobulin production.
• Gut health: Supports mucin (protective mucus) production in the intestines.
• ⚡ Protein balance: Helps maintain proper protein structure through hydrogen bonding.

🧬 Family & Essentiality

🌿 Plain-Language Summary

Threonine is a “structural specialist”. It helps build collagen, elastin, and mucins that keep skin, joints, and the gut lining healthy. It also supports immune function by helping make antibodies. Since your body can’t make it, threonine must come from protein-rich foods.

⚗️ Molecular & Chemical IDs

• Abbreviation: Thr / T
• Chemical formula: C₄H₉NO₃
• Structure: Polar, uncharged side chain (hydroxyl group)

⚡ Functions

• ️ Collagen & elastin: Maintains connective tissue and skin strength.
• Gut barrier: Essential for mucin production in intestines.
• ️ Immunity: Needed for antibody and glycoprotein synthesis.
• Protein metabolism: Balances other amino acids in protein turnover.

🍽️ Absorption & Bioavailability

🇦🇺 Australian NRVs (NHMRC)

• Adults (≥19 yrs) EAR: ~15 mg/kg/day
• RDI: ~20 mg/kg/day

Values based on NHMRC/FAO/WHO amino-acid requirement data, expressed per kilogram body weight.

🥗 Food Sources

• Meat, poultry, fish
• Dairy (milk, yoghurt, cheese)
• Eggs
• Legumes, soy, lentils, nuts, whole grains

Adequate protein intake usually covers threonine needs.

🧪 Testing & Monitoring

• Plasma amino acid profiling (specialist labs).
• ❌ Not a routine clinical test in Australia.

🔄 Interactions

• ➕ Works with glycine and serine in connective tissue and collagen metabolism.
• ➕ Requires vitamin B6 for threonine dehydratase (catabolism).
• ⚠️ Deficiency may impair immunity and gut barrier integrity (rare in varied diets).

🚨 Deficiency & Evidence

Deficiency

Uncommon in balanced diets; potential risk in severe malnutrition or very restricted diets, affecting gut barrier and immune defences.

Evidence Snapshot

• ✅ Established: Essential for collagen, mucin, and antibody production.
• ⚖️ Emerging: Supplementation studied in inflammatory bowel conditions and gut health; not yet standard therapy.