What does a bilirubin level of 0.21 mg/dL indicate?

Interpretation of a Bilirubin Level of 0.21 mg/dL

A bilirubin level of 0.21 mg/dL is within the normal reference range and indicates normal liver function. This value is not a cause for concern and suggests healthy bilirubin metabolism in the body.

Understanding Bilirubin and Its Normal Ranges

Bilirubin is a yellow compound produced during the normal breakdown of red blood cells. The liver processes bilirubin so it can be excreted from the body. Normal total serum bilirubin levels typically range from 0.1 to 1.2 mg/dL in adults.

Types of Bilirubin:

• Unconjugated (indirect) bilirubin: Fat-soluble form that travels in the blood to the liver
• Conjugated (direct) bilirubin: Water-soluble form that has been processed by the liver

Clinical Significance of a 0.21 mg/dL Bilirubin Level

What This Value Means:

• The value of 0.21 mg/dL falls well within normal limits
• It indicates proper functioning of:
  • Red blood cell metabolism
  • Liver processing of bilirubin
  • Biliary excretion pathways

Absence of Liver Disease Indicators:

• No evidence of hepatocellular damage (which would typically show elevated bilirubin)
• No indication of cholestasis or biliary obstruction
• No suggestion of hemolytic processes

Potential Benefits of Normal to Low-Normal Bilirubin

Recent research suggests that bilirubin may have beneficial physiological properties:

• Acts as an endogenous antioxidant 1
• May provide protection against oxidative stress
• Associated with reduced risk of cardiovascular diseases 2
• Potentially linked to lower prevalence of chronic diseases including cancer and Type 2 diabetes 2

When to Be Concerned About Bilirubin Levels

Elevated Bilirubin (Hyperbilirubinemia):

• Values >1.2 mg/dL may indicate:
  • Liver dysfunction
  • Biliary obstruction
  • Hemolytic disorders
  • Certain genetic conditions (e.g., Gilbert syndrome)

Very Low Bilirubin (Hypobilirubinemia):

• Some research suggests that extremely low levels (<0.1 mg/dL) might be associated with:
  • Increased cardiovascular risk 3
  • Reduced antioxidant capacity 1
  • Potential metabolic dysfunction 1

Conclusion

A bilirubin level of 0.21 mg/dL is normal and indicates healthy liver function. This value requires no further investigation or intervention in the absence of other concerning symptoms or laboratory abnormalities. The liver is effectively processing bilirubin from red blood cell breakdown, and the biliary system is functioning properly for excretion.