What is the commercial production of vitamin C?

Over 100,000 tons of vitamin C are produced commercially each year, with more than 90% of the world's production capacity located in China. This massive output relies on sophisticated manufacturing processes to synthesize L-ascorbic acid, primarily from glucose or other carbohydrates, for widespread use across the food, pharmaceutical, and cosmetic industries.

Quick Summary

Commercial vitamin C production has evolved from the multi-step Reichstein process to the modern, more efficient two-step fermentation method. Glucose serves as the primary raw material, converted through a series of chemical and microbial steps involving key intermediates like 2-keto-L-gulonic acid to yield high volumes of pure ascorbic acid.

Key Points

• Dominant Method: The modern two-step fermentation process, originating in China, is the primary method for the commercial production of vitamin C today.

• Raw Material: The main raw material for commercial vitamin C is glucose, a readily available and inexpensive carbohydrate.

• Reichstein Process: The original 1930s Reichstein process was a mix of chemical and microbial steps, now mostly replaced by more efficient methods due to high costs and toxic waste.

• Key Intermediate: A critical intermediate in both the Reichstein and modern methods is 2-keto-L-gulonic acid (2-KLG), which is converted to the final ascorbic acid.

• Broad Applications: Commercial vitamin C is widely used across the food, pharmaceutical, and cosmetics industries for its antioxidant and preservative properties.

• Future Innovations: Research focuses on developing a more sustainable one-step fermentation process to produce vitamin C directly from glucose, further lowering costs and environmental impact.

The historical context and evolution of vitamin C production

Commercial vitamin C production has a rich history, evolving significantly since its discovery and isolation in the early 20th century. The first industrial method, developed by Nobel laureate Tadeusz Reichstein in 1933, laid the groundwork for large-scale synthesis but was eventually superseded by more efficient and cost-effective techniques.

The Reichstein process

The Reichstein process, beginning with D-glucose, involves a combination of chemical and microbial steps to produce vitamin C. Key steps include the hydrogenation of D-glucose to D-sorbitol, followed by microbial oxidation to L-sorbose. Subsequent chemical steps involve protecting the L-sorbose hydroxyl groups, oxidizing the intermediate to 2-keto-L-gulonic acid, and finally cyclizing it to L-ascorbic acid. This method is now largely outdated due to its complexity, use of toxic solvents, and high costs.

The modern two-step fermentation process

Predominant today, the modern two-step fermentation process significantly reduces the chemical steps of the Reichstein method. It begins with the microbial conversion of D-sorbitol to L-sorbose, typically using Gluconobacter oxydans. A second fermentation step, involving a microbial consortium such as Ketogulonicigenium vulgare and a helper organism, transforms L-sorbose into 2-keto-L-gulonic acid (2-KLG). A final chemical conversion then yields pure L-ascorbic acid crystals. This method offers lower costs and reduced environmental impact compared to the Reichstein process.

Comparison of production methods

Feature	Reichstein Process (Older)	Two-Step Fermentation (Modern)
Starting Material	D-Glucose	D-Glucose
Microbial Steps	One	Two
Chemical Steps	Multiple, complex	Fewer, simpler
Environmental Impact	Higher	Lower
Cost	Higher	Lower
Dominance	Limited current use	Industry standard

Applications of commercial vitamin C

The commercially produced L-ascorbic acid is vital for several industries.

Food and beverage industry

Vitamin C acts as an antioxidant and preservative, preventing spoilage and maintaining quality in various food and drink products. It's recognized as a food additive (E300-E304) for its color-retention properties.

Pharmaceutical and cosmetic industries

It is the primary ingredient in dietary supplements and used in skincare for its antioxidant and anti-aging effects. Vitamin C is essential for collagen synthesis and supports immune health.

Other industrial uses

Vitamin C is added to animal feed to improve growth and immunity and serves as a mild reducing agent in chemical processes.

The future of vitamin C production

Ongoing research aims to simplify the production process further. One-step fermentation methods, which could potentially convert glucose directly to vitamin C, are being explored to increase efficiency and sustainability. Advances in biotechnology, such as metabolic engineering, are focused on optimizing microbial strains to enhance yields and reduce production costs, paving the way for more environmentally friendly and economical manufacturing practices.

Conclusion

The history of what is the commercial production of vitamin C highlights a shift from the multi-step Reichstein process to the more efficient two-step fermentation method dominant today. This industrial production, largely centered in China, provides essential L-ascorbic acid for a wide array of applications in the food, pharmaceutical, and cosmetic sectors globally. Future innovations are expected to continue improving efficiency and sustainability, potentially through one-step fermentation processes.

References

• 1.2.1: Across Biotech. (2022). Vitamin C Ascorbic Acid Manufacturers and Production Method [Online]. Available: https://acrossbiotech.com/vitamin-c-ascorbic-acid-manufacturers-and-production-method/.
• 1.4.2: Pan, L., et al. (2018). Industrial Fermentation of Vitamin C. ResearchGate. DOI: 10.13140/RG.2.2.33924.32649.
• 1.4.4: Frazão, V. L., et al. (2025). Vitamin C: A Comprehensive Review of Its Role in Health, Diseases, and Manufacturing. MDPI. DOI: 10.3390/molecules30030748.
• 1.5.2: Reichstein, T. and Grüssner, A. (1934). Eine ergiebige Synthese der L-Ascorbinsäure (C-Vitamin). Helvetica Chimica Acta, 17, pp. 311–328.
• 1.6.2: Lyu, S., et al. (2022). Microbial Interactions in a Vitamin C Industrial Fermentation System. National Institutes of Health (NIH). DOI: 10.3389/fmicb.2022.9499031.

Frequently Asked Questions

What are the main methods for the commercial production of vitamin C?

The main industrial methods for producing vitamin C (ascorbic acid) are the traditional Reichstein process and the modern two-step fermentation process, with the latter being the dominant method used today due to its higher efficiency and lower cost.

What is the Reichstein process for making vitamin C?

The Reichstein process is an older, combined chemical and microbial method that starts with D-glucose. It converts glucose to sorbitol, then ferments it to sorbose, and finally uses several complex chemical steps to convert sorbose into ascorbic acid.

How does the two-step fermentation process work?

In the two-step fermentation process, D-sorbitol is converted to L-sorbose in the first step using bacteria like Gluconobacter oxydans. A second fermentation using a microbial consortium then converts the L-sorbose into 2-keto-L-gulonic acid (2-KLG), which is chemically converted to vitamin C.

Why did the modern two-step fermentation process replace the Reichstein process?

The two-step fermentation process is more cost-effective and environmentally friendly than the Reichstein process. It replaces several complex chemical reactions with additional fermentation steps, reducing the use of toxic solvents and waste generation.

What is the primary raw material for commercial vitamin C production?

The primary raw material for industrial production of vitamin C is glucose, a simple sugar derived from crops like corn, which is converted to D-sorbitol at the beginning of the manufacturing process.

Where is most commercial vitamin C produced?

A large majority of the world's commercial vitamin C production capacity, over 90%, is concentrated in China, where the efficient two-step fermentation process is widely used.

What are the major industrial uses of commercially produced vitamin C?

Commercially produced vitamin C is used as a dietary supplement in pharmaceuticals, as an antioxidant and preservative in the food and beverage industry, and for its skin health benefits in the cosmetic industry.