Where Do Carnivores Get Their Vitamin C?

December 25, 2025 •

3 min read

Most animals, including the majority of carnivores, have a fascinating metabolic trick that humans lack: they can synthesize their own vitamin C internally. This ability, however, was lost in our evolutionary lineage, raising a common question about how meat-eaters obtain this essential nutrient. The answer is a surprising combination of endogenous production and specific dietary sources.

Quick Summary

Carnivores get vitamin C primarily by synthesizing it in their own livers or kidneys, unlike humans and other primates. For those on a carnivorous diet, sources include organ meats, fresh muscle meat, and seafood.

Key Points

Internal Synthesis: Most carnivorous animal species can produce their own vitamin C in their liver or kidneys, making dietary intake unnecessary.
Human Anomaly: Humans, along with other primates and guinea pigs, are unable to synthesize vitamin C due to a genetic mutation and must get it from food.
Organ Meats are Key: For humans on a carnivore diet, organ meats like spleen, kidney, and liver are the most concentrated and bioavailable sources of vitamin C.
Fresh Meat Provides Trace Amounts: Fresh, unprocessed muscle meat contains small amounts of vitamin C, but much of it is lost during cooking.
Reduced Need on Low-Carb Diet: In the absence of carbohydrates, the body's vitamin C requirements are significantly lower because there is no competition for absorption pathways with glucose.
Seafood is a Source: Nutrient-dense seafood, such as fish roe and oysters, provides additional vitamin C for those on a meat-only diet.

The Internal Vitamin C Factory: How Most Carnivores Do It

The most straightforward answer to the question is that most carnivorous species do not need to seek out vitamin C from their food because their bodies produce it internally. This process, which occurs in the liver or kidneys, converts glucose into ascorbic acid, the chemical name for vitamin C. This internal synthesis makes dietary vitamin C intake redundant for them, a stark contrast to humans who must obtain it from external food sources to prevent deficiency diseases like scurvy.

The Evolutionary Anomaly of Primates

The loss of the ability to produce vitamin C is a significant evolutionary event that sets humans, other primates, and a few other animal species apart. This is due to a mutation in the GULO gene, which encodes the enzyme L-gulonolactone oxidase, the last enzyme in the vitamin C synthesis pathway. Since our ancestors consumed high amounts of vitamin C from fruit-rich diets, the selective pressure to maintain the functional gene was lost. For obligate carnivores that can't make their own, their evolutionary path never included relying on abundant, external plant sources, so the gene was not lost.

Vitamin C Sources for Carnivorous Dieters

For humans intentionally following a carnivore diet, the question of vitamin C becomes highly relevant. Without plant-based sources, individuals must rely on other means to meet their needs, which are often reduced on a low-carb diet.

Organ Meats

Beef Liver: A rich source of many nutrients, beef liver provides a bioavailable form of vitamin C.
Beef Kidney: Even more concentrated than liver, beef kidney is an excellent, though often less palatable, source of vitamin C.
Spleen: Beef spleen is exceptionally high in vitamin C, making it a valuable addition for those seeking to maximize their intake.
Thymus: Also a potent source of vitamin C, beef thymus can contribute significantly to a carnivore's micronutrient intake.

Fresh Muscle Meat and Seafood

Fresh Meat: While in very low amounts, fresh, unprocessed, and lightly cooked muscle meat does contain some vitamin C. Overcooking, however, can destroy this heat-sensitive nutrient.
Fish Roe: A surprisingly good source, fish roe (caviar) is packed with nutrients, including a notable amount of vitamin C.
Oysters: These shellfish offer a decent dose of vitamin C per serving.

Dietary Strategy for Vitamin C on a Carnivore Diet

For humans on a strict carnivore diet, the key to avoiding deficiency is not only what they eat, but also how their body utilizes the nutrient. Vitamin C and glucose compete for the same transport mechanisms in the body. When carbohydrates are drastically reduced, as they are on a carnivore diet, this competition diminishes, and the body's need for and utilization of vitamin C become more efficient. This means that the smaller quantities found in animal products are often sufficient for those with a low-carb metabolism.

Nutrient Content Comparison: Organ Meats vs. Plants


Food Source	Vitamin C Content (per 100g)	Primary Source for Diet	Considerations for Carnivores
Beef Spleen	~45.5 mg	Animal Product	Excellent source, highly concentrated
Beef Kidney	~9.4 mg	Animal Product	Good source, might be less palatable
Beef Liver	~4 mg	Animal Product	Accessible and nutrient-dense
Fish Roe	~16 mg	Animal Product	Nutrient-dense, good for omega-3s
Oysters	~12 mg	Animal Product	Rich source from seafood
Orange	~53 mg	Plant Product	Not carnivore diet-approved
Bell Peppers	~80 mg (approx.)	Plant Product	Not carnivore diet-approved

Conclusion

The mystery of how carnivores obtain vitamin C has a dual answer rooted in evolutionary biology and metabolic science. Most animal carnivores have retained the ability to synthesize their own vitamin C internally, making dietary sources unnecessary for them. In contrast, humans, who lost this capacity millions of years ago, must obtain it from their diet. For human carnivore dieters, the nutrient is sourced from organ meats, fresh muscle meat, and seafood. Furthermore, the body's reduced vitamin C requirements on a low-carb diet mean that the smaller quantities found in animal products are sufficient to prevent deficiency. Ultimately, the carnivorous lifestyle—whether for a tiger or a human dieter—demonstrates a perfectly adapted nutritional pathway that sidesteps the plant-based sources traditionally associated with this vital nutrient.

Frequently Asked Questions

No, most carnivorous animals cannot get scurvy because their bodies have the necessary enzymes to synthesize their own vitamin C internally, preventing the deficiency that causes the disease.

Organ meats, particularly the spleen, kidney, and liver, are the richest sources of vitamin C for human carnivore dieters. Beef spleen, for example, contains a very high concentration.

Yes, fresh, raw, or lightly cooked muscle meat contains trace amounts of vitamin C. However, the concentration is low and much of it is destroyed by extensive cooking.

Humans need to consume vitamin C because they lack the GULO enzyme required for its internal synthesis. Our ancestors, who ate a high-fruit diet, lost the gene, unlike most carnivores who never relied on external sources.

People on a low-carb, carnivore diet typically require far less vitamin C than those on a standard high-carb diet, with some reports suggesting adequate intake with as little as 10-20 mg daily from animal foods.

Cooking meat significantly reduces its vitamin C content, especially at high temperatures. Minimal cooking preserves more of the small amount present in fresh muscle meat and organ meats.

While bone broth is a healthy part of some carnivore diets, it is not a significant source of vitamin C, as the vitamin is largely absent from bones.