Your Short-Term Nutritional Status Indicator
Albumin tells you about protein status over the past 3 weeks (long half-life). Prealbumin tells you about the past 2-3 DAYS (short half-life). This makes prealbumin a much faster indicator of whether nutritional support is working. If you start feeding a malnourished patient and prealbumin rises, you're winning. If it falls, the patient is losing ground.
What is Prealbumin (Transthyretin)?
Prealbumin (transthyretin) transports thyroxine (T4) and retinol-binding protein (vitamin A). Made by liver. Half-life: 2-3 days (vs albumin's 21 days). Negative acute phase reactant (drops during inflammation). Must interpret with CRP—low prealbumin with high CRP = inflammation, not necessarily malnutrition.
↑ What High Prealbumin (Transthyretin) Means
Rare. Steroid use, high-protein diet, kidney disease (reduced catabolism).
Common symptoms:
Not typically symptomatic
↓ What Low Prealbumin (Transthyretin) Means
Malnutrition OR acute inflammation OR liver disease. Here's the catch: prealbumin is a negative acute phase reactant—it drops during ANY inflammation, even if nutrition is fine. You MUST check CRP alongside prealbumin to interpret it correctly.
Common symptoms:
Fatigue, weakness · Muscle wasting · Poor wound healing · Hair loss, brittle nails · Edema (if severe protein malnutrition)
Why It Matters
When normal:
Rapid nutrition assessment (reflects past 2-3 days)
Monitors nutritional support response (should rise ~4 mg/dL per week)
More responsive than albumin for acute changes
Predicts surgical outcomes (low prealbumin = higher complications)
Risks if abnormal:
Low: malnutrition, inflammation, liver disease (can't distinguish without CRP)
Falls during ANY inflammation regardless of nutrition
Overinterpreted if CRP not checked simultaneously
What Can Cause Abnormal Levels?
Acute Inflammation (low)
40% likelyNegative acute phase reactant. Any infection, surgery, or inflammatory condition drops prealbumin.
Protein-Calorie Malnutrition (low)
35% likelyInsufficient protein intake reduces hepatic prealbumin synthesis.
Liver Disease (low)
Liver produces prealbumin. Reduced synthesis in liver disease.
Hyperthyroidism (low)
Increased thyroxine turnover reduces transthyretin.
Nephrotic Syndrome (low)
Urinary protein loss includes prealbumin.
What You Can Do
ALWAYS check CRP alongside prealbumin
Impact: If CRP elevated, low prealbumin likely reflects inflammation, NOT malnutrition \u00B7 Timeline: Always together
If malnourished: increase protein to 1.2-1.5 g/kg/day
Impact: Prealbumin should rise ~4 mg/dL per week with adequate nutrition \u00B7 Timeline: Weekly monitoring
If lifestyle changes aren't enough:
Monitor prealbumin weekly in hospitalized patients on nutritional support
Impact: Faster feedback than albumin on nutritional adequacy \u00B7 Timeline: Weekly
Enteral nutrition preferred over TPN when gut is functional
Impact: Maintains gut integrity and immune function \u00B7 Timeline: As tolerated
Recommended retest: Weekly during nutritional support; always with CRP for proper interpretation
Related Markers
Got your blood test report?
Upload your PDF and understand ALL your markers in 2 minutes. Plain language. Traffic light status. No medical jargon.
Analyze My Report — FreeFirst report is free. No credit card needed.