Which Blood Carries Nutrients Throughout the Body?

December 24, 2025 •

2 min read

The human body is an intricate machine, with the circulatory system acting as its delivery network, transporting essential cargo to every cell. While often seen as a single fluid, blood is composed of several parts, and it is the liquid component—blood plasma—that is primarily responsible for carrying absorbed nutrients.

Quick Summary

Blood plasma is the liquid component that primarily carries nutrients like glucose and amino acids to the body's cells. These nutrients are absorbed from the digestive system and distributed via the circulatory system's network of arteries, veins, and capillaries, with the lymphatic system handling fats.

Key Points

Blood Plasma is the Primary Carrier: The liquid component of blood, known as plasma, is the main transport medium for water-soluble nutrients like glucose and amino acids.
Nutrients are Absorbed from the Small Intestine: After digestion, nutrients are absorbed into the bloodstream through the lining of the small intestine, specifically the villi.
Fats are Transported by the Lymphatic System: Fat and fat-soluble vitamins are absorbed into lymph vessels (lacteals) and travel via the lymphatic system before entering the bloodstream.
The Liver Processes and Distributes Nutrients: The hepatic portal vein carries water-soluble nutrients directly from the small intestine to the liver for processing before distribution.
Capillaries Facilitate Nutrient Exchange: The exchange of nutrients and waste products between blood and body cells occurs in the thin-walled capillary beds.
Red Blood Cells Carry Oxygen, Not Nutrients: The main function of red blood cells is to transport oxygen and carbon dioxide, while nutrients are carried dissolved in the plasma.

The Dual Pathway of Nutrient Transport

Ensuring every cell receives nourishment requires a sophisticated transport system involving both the circulatory and lymphatic systems.

Blood Plasma: Transporting Water-Soluble Nutrients

Blood plasma, constituting about 55% of blood volume, is a liquid that carries dissolved substances. It is the main transporter for most nutrients absorbed from the small intestine, including glucose, amino acids, water-soluble vitamins, minerals, and electrolytes. After absorption into intestinal capillaries, these nutrients travel via the hepatic portal vein to the liver for processing and regulation before being distributed.

The Lymphatic System: Handling Fats

Fats and fat-soluble vitamins require a different route because they don't dissolve in water. They are absorbed into lacteals, which are lymphatic vessels in the small intestine villi. This fatty fluid, called chyle, travels through the lymphatic system and eventually enters the bloodstream near the heart.

The Journey from Digestion to Circulation

Nutrients follow a path from food to cells. Digestion breaks down food into simpler forms that are absorbed in the small intestine: water-soluble nutrients enter the bloodstream, and fats enter the lymph. These systems then transport the nutrients throughout the body. At the capillaries, nutrients and oxygen move from the blood into tissues and cells, while waste products are collected by the blood for removal.

Comparison Table: Nutrient Transport Routes


Feature	Blood Plasma (Circulatory System)	Lymphatic System
Primary Function	Water-soluble nutrient and gas transport.	Fat, fat-soluble vitamin, and fluid transport.
Nutrients Carried	Glucose, amino acids, minerals, water-soluble vitamins.	Fats, fat-soluble vitamins (A, D, E, K).
Entry Point	Intestinal capillaries.	Intestinal lacteals.
Initial Path	Via hepatic portal vein to the liver.	Via lymphatic vessels.
Final Entry to Blood	Directly absorbed.	Drains into bloodstream near the heart.

Clarifying the Role of Red Blood Cells

Red blood cells primarily transport oxygen via hemoglobin. While they are part of the blood that circulates, they do not carry nutrients; nutrients are dissolved in the plasma that surrounds the red blood cells.

Nutrient Delivery at the Capillaries

Capillaries are the sites where nutrients from the plasma and oxygen from red blood cells are exchanged with body cells. Their thin walls and narrow structure allow for efficient diffusion of substances between the blood and tissues, while waste products enter the blood.

Conclusion: The Combined Effort of Blood and Lymph

The transport of nutrients relies on the entire blood system and the lymphatic system working together. Blood plasma is key for water-soluble nutrients, while the lymphatic system is essential for fats. This coordinated process, driven by the heart, ensures every cell receives the necessary fuel for life. Understanding this complex network highlights the body's remarkable efficiency. For more information on blood functions, the American Society of Hematology is a valuable resource.

Frequently Asked Questions

The liquid part of blood, called plasma, is what specifically carries most nutrients like glucose, amino acids, vitamins, and minerals. It's a watery solution that transports these dissolved substances throughout the body.

No, red blood cells do not transport nutrients. Their primary function is to carry oxygen from the lungs to the body's tissues and bring carbon dioxide back to the lungs for exhalation.

Fats and fat-soluble vitamins are absorbed into the lymphatic system through vessels called lacteals, not directly into the bloodstream. The lymphatic system then transports this milky fluid, known as chyle, until it eventually joins the blood circulation near the heart.

Nutrients enter the bloodstream from the small intestine. The inner lining of the small intestine has tiny, finger-like projections called villi, which contain capillaries and lacteals that absorb digested food particles.

After water-soluble nutrients are absorbed, they are transported via the hepatic portal vein directly to the liver. The liver then processes these nutrients, storing some for later use and preparing others for distribution to the rest of the body.

Nutrients move from the blood to the body's cells through the capillaries. The thin walls of capillaries allow nutrients and oxygen to diffuse from the plasma into the surrounding tissue fluid, where cells can then absorb them.

Water-soluble nutrients are absorbed directly into the bloodstream and processed by the liver. Fat-soluble nutrients, being insoluble in water, are absorbed into the lymphatic system first and later join the bloodstream, bypassing the liver initially.