Can You Get Vitamin C From Grass?

December 2, 2025 •

3 min read

A 2018 study on cereal grasses found that fresh barley grass can contain up to 25.4 mg of Vitamin C per 100 grams, but humans cannot effectively absorb this nutrient from lawn grass. The answer to whether you can get vitamin C from grass for human benefit is more complex than it might seem, hinging on human digestive limitations and the form of the plant material.

Quick Summary

This article explores the truth about whether humans can get vitamin C from consuming grass. It details the digestive differences between humans and herbivores, the bioavailability of nutrients in grass, and why certain plant-based supplements are an exception.

Key Points

Human Digestion Lacks Cellulase: Unlike herbivores, humans do not produce the enzyme needed to break down the fibrous cell walls of grass, making nutrient absorption impossible.
Vitamin C is Trapped: The vitamin C within grass remains locked inside the indigestible plant cells and cannot be utilized by the human body.
Raw Grass is Harmful: Attempting to eat unprocessed lawn grass can cause severe gastrointestinal issues and offers no nutritional benefit.
Juiced Grass is Different: Processed products like wheatgrass juice break down the cell walls, making the nutrients, including vitamin C, bioavailable.
Rely on Fruits and Vegetables: For consistent and safe vitamin C intake, stick to established sources like citrus fruits, bell peppers, broccoli, and berries.
Hay is Devoid of Vitamin C: Cured grass (hay) has almost no vitamin C due to oxidation during the drying process, making it an even less viable source.

Is Grass a Viable Source of Vitamin C for Humans? The Digestive Divide

While it is technically true that green plants, including many types of grass, produce and contain vitamin C, this does not mean it is a viable nutritional source for humans. The primary issue is the human digestive system, which is not equipped to break down the tough cellulose found in grass cell walls. In contrast, herbivores like cows, sheep, and horses possess specialized digestive systems with multiple stomachs (in the case of ruminants) and specific enzymes that allow them to ferment and break down cellulose, releasing the locked-in nutrients. For humans, attempting to eat raw grass from a lawn would not only be nutritionally inefficient but could also be harmful, potentially leading to gastrointestinal distress or even a perforated small intestine.

The Role of Cellulose in Nutrient Absorption

Cellulose is a complex carbohydrate that forms the structural component of plant cell walls. Humans lack the enzyme cellulase needed to digest it. This means that when we consume plant matter with high cellulose content, it passes through our system largely undigested. While this insoluble fiber is beneficial for gut health and bowel regularity, it prevents us from accessing the vitamins and minerals stored within the plant cells. The vitamin C, along with other nutrients, remains trapped and is excreted from the body.

Fresh Grass vs. Concentrated Supplements

An important distinction must be made between grazing on fresh lawn grass and consuming concentrated, processed supplements like wheatgrass juice or barley grass powder. While fresh pasture grass offers little to no usable vitamin C for humans due to the cellulose barrier, certain grass-based products are designed specifically for human consumption.

Here are some reasons these products differ:

Processing: Wheatgrass and barley grass products are typically juiced or powdered. This processing method breaks down the cell walls, releasing the nutrients, including vitamin C, and making them bioavailable for human absorption.
Concentration: Juicing concentrates the vitamins and minerals, meaning a small serving of wheatgrass juice contains a much higher dose of nutrients than a large amount of raw grass.
Type of Grass: Cereal grasses like wheat and barley are often used for human-grade supplements and microgreens, and are different from the turf grasses found on lawns.

Other Reliable Sources of Vitamin C

Since relying on grass is not a sound strategy for meeting your vitamin C needs, it's essential to turn to proven and easily digestible sources. Fruits and vegetables are the gold standard for a healthy diet, and many offer excellent levels of vitamin C.

Common high-vitamin C foods include:

Citrus Fruits: Oranges, lemons, and grapefruit are classic sources, as is their juice.
Bell Peppers: Red and green peppers are packed with vitamin C.
Berries: Strawberries, blackcurrants, and raspberries are great options.
Cruciferous Vegetables: Broccoli, Brussels sprouts, and kale all contain significant amounts.
Kiwifruit: A small, green kiwifruit provides a considerable percentage of your daily requirement.

Comparison Table: Digesting Grass vs. Traditional Vitamin C Sources


Feature	Eating Raw Lawn Grass	Juiced Cereal Grass	Eating an Orange
Digestibility for Humans	Extremely low; cellulose indigestible.	High; cell walls are broken down.	High; readily digestible.
Vitamin C Bioavailability	Virtually none; trapped in cell walls.	High; nutrients are released by processing.	High; easily absorbed.
Taste & Palatability	Poor; not intended for human consumption.	Earthy and potent flavor; often mixed with other juices.	Pleasant, sweet, or tart flavor.
Gastrointestinal Effects	Risk of distress, nausea, and intestinal perforation.	Can cause nausea in large quantities; generally safe.	Safe, unless an allergy or high acidity is an issue.
Source of Nutrients	Primarily water and indigestible fiber.	Concentrated vitamins, minerals, and antioxidants.	Balanced mix of vitamins, fiber, and other nutrients.

Conclusion: Can You Get Vitamin C From Grass? The Takeaway

In summary, while grass contains vitamin C, its bioavailability is zero for humans due to our inability to digest the fibrous cellulose cell walls. Our digestive systems are fundamentally different from those of ruminant animals. For those interested in the concentrated nutrients of grass, processed supplements like wheatgrass juice offer a digestible alternative by breaking down the plant's cellular structure. However, the most reliable and safest method for obtaining this essential vitamin is through a varied diet rich in fruits and vegetables, as recommended by health authorities. A balanced approach is to prioritize proven dietary sources and to consult a healthcare professional before relying on supplements.

Visit the National Institutes of Health (NIH) website for more detailed information on vitamin C.

Frequently Asked Questions

Humans lack the necessary enzyme, cellulase, to break down the tough cellulose cell walls in grass. This means the nutrients, including vitamins, remain trapped and pass through the digestive system unused.

No, they are fundamentally different. Wheatgrass juice is processed to break down the cell walls, releasing the concentrated nutrients for the body to absorb. Eating raw lawn grass provides no nutritional benefit and can be harmful.

Consuming unprocessed grass can lead to a number of health issues, including gastrointestinal upset, nausea, and in severe cases, a perforated small intestine due to its fibrous, indigestible nature.

Excellent and easily digestible sources include citrus fruits like oranges and grapefruit, bell peppers, strawberries, broccoli, Brussels sprouts, and kiwifruit.

No. While fresh green grass contains vitamin C, the drying process that turns grass into hay destroys the vitamin C content through oxidation. Herbivores rely on other aspects of their diet or synthesis for this nutrient.

Herbivores have specialized digestive systems, often with multiple stomach compartments, that contain specific enzymes and bacteria. This allows them to effectively ferment and break down cellulose to extract nutrients.

Evolutionarily, the human digestive system is adapted for omnivorous diets, and developing the complex mechanisms of herbivores would require millions of years of adaptation. It is not a practical or foreseeable dietary shift.