The Liver: What Is the Main Source of Albumin?

January 9, 2026 •

2 min read

Albumin is the most abundant protein in human blood plasma, making up more than half of the total protein content. This crucial protein is exclusively synthesized by a single organ, which acts as the body's primary factory for its production. Understanding what is the main source of albumin is fundamental to comprehending its role in maintaining human health.

Quick Summary

The liver is the sole site of albumin synthesis in the body. This vital protein is essential for maintaining oncotic pressure and transporting critical substances throughout the bloodstream.

Key Points

The liver synthesizes all albumin: The body's main source of albumin is produced exclusively by hepatocytes in the liver.
Albumin maintains oncotic pressure: It keeps fluid from leaking out of blood vessels, preventing edema and regulating blood volume.
Diet provides amino acid building blocks: Foods high in protein, such as eggs and meat, supply the raw materials, but the liver does the manufacturing.
Low albumin indicates health issues: Conditions like liver or kidney disease and malnutrition are common causes of hypoalbuminemia.
Albumin is a critical transporter: It carries hormones, vitamins, fatty acids, and drugs throughout the body.

The Liver: The Body's Albumin Factory

The liver, located in the upper right side of the abdomen, is the exclusive site for albumin synthesis. Specialized cells in the liver, called hepatocytes, are responsible for producing and secreting this protein into the bloodstream. A healthy adult liver typically produces about 12–14 grams of albumin daily. Factors like nutrition, hormones, and overall liver health influence this production. Liver conditions such as cirrhosis or hepatitis can decrease albumin production and lead to health issues.

How Albumin is Produced in the Liver

Albumin synthesis begins in hepatocytes with gene transcription and translation. The protein is modified before being secreted into the bloodstream. Nutritional intake impacts this process; malnutrition can reduce albumin production.

Key Functions of Albumin

Albumin is crucial for numerous bodily functions:

Maintaining Oncotic Pressure: Albumin helps keep fluid within blood vessels, preventing swelling (edema).
Transporting Substances: It carries hormones, fatty acids, bilirubin, calcium, and drugs.
Buffering Blood pH: Albumin helps maintain the blood's acid-base balance.
Antioxidant Effects: It protects against oxidative stress.

The Impact of Low Albumin Levels

Low albumin levels, known as hypoalbuminemia, can be caused by:

Severe Liver Disease: Conditions like cirrhosis impair albumin synthesis.
Malnutrition: Lack of dietary protein reduces the building blocks for albumin.
Kidney Disease: Nephrotic syndrome can cause albumin loss in urine.
Infections and Inflammation: These can reduce albumin synthesis.

Low albumin can lead to fluid accumulation, fatigue, and impaired transport of essential substances.

Comparison of In-Body vs. Food Sources of Albumin


Feature	In-Body (Liver Synthesis)	Food Sources
Primary Function	Systemic regulation: maintains oncotic pressure, transports substances, and acts as a buffer.	Nutritional intake: provides amino acids for the body to synthesize its own proteins.
Source	Produced exclusively by the liver's hepatocytes.	Consumed through protein-rich foods like meat, eggs, dairy, and some legumes.
Direct Absorption	Secreted directly into the bloodstream in its functional form.	Broken down into amino acids during digestion before absorption.
Bioavailability	100% direct use as functional protein.	Varies depending on the source and digestion process.
Dependence	Dependent on liver health, nutritional status, and hormonal signals.	Dependent on dietary choices and the digestive system's ability to absorb amino acids.

Can Food Be the Main Source of Albumin?

Protein-rich foods are not the main source of the functional albumin in your blood. Instead, they supply amino acids that the liver uses to create its own albumin. Your diet provides the raw materials, and the liver manufactures the protein.

Conclusion

The liver is the main source of albumin. It exclusively synthesizes this vital protein, which performs essential functions like maintaining fluid balance, transporting molecules, and providing antioxidant effects. While a protein-rich diet supplies the amino acids needed for production, the liver is the sole site of albumin synthesis. Liver health is therefore critical for maintaining adequate albumin levels and overall well-being. Keeping the liver healthy through good nutrition and lifestyle supports the production of this vital protein.

Learn more about the role of the liver in health here.

Frequently Asked Questions

The primary function of albumin is to maintain oncotic pressure, which is the pressure that prevents fluid from leaking out of blood vessels and into surrounding tissues. It also acts as a carrier for hormones, fatty acids, and other substances.

Severe liver disease, such as cirrhosis, damages the hepatocytes, which are the liver cells responsible for producing albumin. With fewer healthy cells, the liver's capacity to synthesize albumin is reduced, leading to lower levels in the blood.

While you cannot directly absorb functional albumin from food, consuming a protein-rich diet provides the necessary amino acids for your liver to synthesize its own albumin. Foods like lean meats, fish, eggs, and dairy are excellent sources of these building blocks.

Hypoalbuminemia is the medical term for abnormally low levels of albumin in the blood. It can be a sign of liver disease, kidney problems, malnutrition, or severe infection.

Albumin, often derived from human plasma, is used in medical treatments to increase blood volume in patients with severe bleeding, shock, or severe dehydration. It is also used to treat low albumin levels caused by other medical conditions.

Yes, egg whites contain a type of protein called ovalbumin. While related by name and function as a nutrient storage protein, it is not the same as serum albumin, the type produced by the human liver.

In addition to hormones and fatty acids, albumin transports bilirubin, calcium, various drug molecules, and antioxidants throughout the bloodstream.