What are synthetic vitamins made of? Sources and Manufacturing

October 24, 2025 •

4 min read

While most consumers associate vitamins with fresh produce, a large portion of dietary supplements contain synthetic vitamins, created artificially in a lab. Understanding what are synthetic vitamins made of reveals a complex manufacturing process that utilizes a range of chemical compounds and biotechnological methods.

Quick Summary

Synthetic vitamins are artificially produced in laboratories using chemical synthesis, fermentation, or a combination of both. Raw materials can include petrochemicals, processed sugars, acids, and yeast cultures to replicate natural nutrient structures.

Key Points

Industrial Sourcing: Synthetic vitamins are made from industrial chemicals like coal tar, petroleum derivatives, and processed sugars, not directly from whole foods.
Manufacturing Processes: Production methods include chemical synthesis, fermentation using microorganisms (for vitamins like B12), and irradiation (for vitamin D).
Nutrient Identity: While some synthetic vitamins are chemically identical to natural ones, the manufacturing process differs significantly from how nutrients are produced in nature.
Bioavailability and Co-factors: Many synthetic vitamins are isolated nutrients, lacking the co-factors and enzymes found in whole foods that aid absorption and utilization.
Label Identification: You can often identify synthetic vitamins by looking for chemical names (e.g., ascorbic acid, cyanocobalamin) or prefixes like 'dl-' on the product label.
Cost-Effectiveness: Synthetic vitamins are generally cheaper to produce and more stable with longer shelf lives compared to their natural counterparts.

The Industrial Production of Synthetic Vitamins

Unlike their natural counterparts derived from whole foods, synthetic vitamins are manufactured through a controlled, industrial process that can vary by vitamin type. These methods are often chosen for their efficiency, cost-effectiveness, and ability to produce large, consistent batches of isolated nutrients. The fundamental approach involves using chemical reactions or leveraging microbial life to synthesize the desired compound.

Chemical Synthesis: From Raw Materials to Isolated Nutrients

For many fat-soluble and water-soluble vitamins, chemical synthesis is the primary production method. The starting materials are often surprisingly industrial. Coal tar, a byproduct of coal processing, is a foundational substance for some B vitamins. Petroleum extracts and esters are also used in the creation of various vitamins, including some forms of vitamin A. The process involves a series of controlled chemical reactions, often requiring acids, solvents, and heat, to build the vitamin's molecular structure. A notable example is synthetic vitamin C (ascorbic acid), which is frequently derived from corn sugar that undergoes hydrogenation and treatment with acetone. These processes aim to produce a molecule that is chemically identical to or a near-analogue of the nutrient found in nature.

Fermentation and Biotechnology

For certain vitamins, especially vitamin B12, fermentation processes are the only viable commercial method, as the natural source is bacterial activity. This process involves cultivating specific strains of genetically engineered bacteria or yeast in nutrient-rich mediums. The microorganisms metabolize sugars and other raw materials, producing the vitamin as a byproduct. The vitamin is then harvested from the bacterial or yeast suspension, purified, and prepared for use in supplements or fortified foods. This method is often more sustainable than traditional chemical synthesis but still involves a high degree of processing to isolate the final nutrient. Vitamin D2 is another example, created by irradiating fungi with ultraviolet light.

Raw Ingredients for Common Synthetic Vitamins

Synthetic Vitamin A (Retinyl Acetate/Palmitate): Can be derived from petrochemicals, acetylene, benzene, and refined oils.
Synthetic Vitamin B1 (Thiamine Hydrochloride/Mononitrate): Often synthesized using coal tar derivatives, acetone, and hydrochloric acid.
Synthetic Vitamin B9 (Folic Acid/Pteroylglutamic Acid): Chemically produced, though more bioavailable than natural folate from some food sources.
Synthetic Vitamin C (Ascorbic Acid): Commonly produced via a two-step fermentation and chemical process using corn sugar or rice starch as the starting material.
Synthetic Vitamin D3 (Cholecalciferol): Often made by irradiating a substance derived from sheep's wool (lanolin) with ultraviolet light.
Synthetic Vitamin E (dl-alpha-tocopherol): Formulated using petrochemicals and refined vegetable oils.

Synthetic vs. Natural Vitamins: A Comparison


Feature	Synthetic Vitamins	Natural Vitamins
Source	Artificially created in a lab from chemical compounds.	Extracted from whole food sources like plants, animals, or microorganisms.
Purity	Often isolated nutrients, lacking the complex array of co-factors and enzymes found in food.	Come as part of a complex matrix of other nutrients, which can enhance absorption and function.
Cost	Generally more affordable to produce on a large scale.	Can be more expensive due to sourcing and processing methods.
Bioavailability	Variable; some are poorly absorbed (e.g., synthetic vitamin E), while others (e.g., folic acid) may have higher absorption rates.	Often more readily absorbed and utilized by the body due to co-factors and synergy.
Stability	Usually more stable, allowing for a longer shelf life.	Can be sensitive to heat, light, and oxygen, which may degrade them.

How to Identify Synthetic Ingredients

Identifying a synthetic vitamin often comes down to reading the product label. When a supplement lists the chemical name of the vitamin, it is almost certainly synthetic. For example, a synthetic vitamin C is listed as 'Ascorbic Acid,' whereas a natural source might state 'Vitamin C from Acerola Cherries'.

Another tell-tale sign for certain synthetic vitamins is a specific naming convention. The prefix 'dl-' before a vitamin name, such as 'dl-alpha-tocopherol' for Vitamin E, indicates a synthetically derived version. By contrast, the natural form of Vitamin E is called 'd-alpha-tocopherol'. For more information on identifying synthetic ingredients, it's helpful to become familiar with the different chemical names and processes used. A comprehensive guide can help navigate supplement labels and understand the origins of your vitamins.

Conclusion: Making an Informed Choice

Synthetic vitamins provide a cost-effective and convenient way to meet nutritional needs, address specific deficiencies, and fortify foods. However, the raw materials and isolation from natural co-factors mean they are not a perfect substitute for a balanced, whole-food diet. The potential for poorer absorption, reduced effectiveness, and even toxicity in high doses highlights the importance of informed supplementation. Whether choosing synthetic or natural supplements, consumers should prioritize a diverse and nutrient-dense diet, using supplements to address diagnosed deficiencies rather than relying on them as a nutritional shortcut. Consulting a healthcare professional can provide personalized guidance to ensure optimal health outcomes.

Frequently Asked Questions

The primary difference lies in their origin and manufacturing process. Natural vitamins are extracted from whole food sources, while synthetic vitamins are artificially created in a lab using chemical synthesis or fermentation.

Effectiveness varies by vitamin. Some studies suggest certain natural vitamins, like Vitamin E, are absorbed more efficiently, while some synthetic forms, like folic acid, may have higher absorption rates. Natural vitamins from whole foods also contain beneficial co-factors that synthetic versions lack.

Synthetic vitamin C is commonly produced from corn sugar or rice starch through a two-step fermentation and chemical process.

Synthetic vitamin B1, often listed as thiamine hydrochloride or mononitrate, is frequently synthesized using coal tar derivatives, acetone, and hydrochloric acid as raw materials.

No. Synthetic vitamins should not replace a balanced diet rich in whole foods. A varied diet provides a complex matrix of vitamins, minerals, and other compounds that work synergistically for optimal health.

In high doses, particularly with fat-soluble vitamins (A, D, E, K), synthetic vitamins can pose a risk of toxicity, as they can accumulate in the body. It is important to follow recommended dosages and consult a healthcare professional.

Manufacturers often use synthetic vitamins because they are cheaper to produce, more stable, have a longer shelf life, and can be made in precise, consistent dosages.

The most common way is to check the label for the prefix 'dl-'. Synthetic vitamin E is listed as 'dl-alpha tocopherol,' whereas the natural form is 'd-alpha tocopherol'.