How are vitamins made naturally?

November 21, 2025 •

4 min read

Over 2 billion people worldwide suffer from micronutrient deficiencies, underscoring the critical importance of these compounds in our diet. This highlights the necessity of understanding how are vitamins made naturally, primarily through plants and microorganisms, rather than relying solely on synthetic supplements.

Quick Summary

This article explores the biological processes through which vitamins are naturally produced in plants, animals, and microorganisms. It details the specific synthesis pathways for various vitamins, from photosynthesis in plants to bacterial fermentation in the gut. The content compares natural food sources and discusses how natural vitamins are absorbed and utilized by the body more effectively due to co-factors present in whole foods.

Key Points

Plant Production: Most vitamins originate from plants, which synthesize them from sunlight and soil nutrients through photosynthesis.
Microbial Synthesis: Bacteria, including those in our gut, are essential producers of B vitamins (like B12 and folate) and Vitamin K.
Sunlight and Skin: Vitamin D is uniquely produced by our skin in response to exposure to ultraviolet B (UVB) rays from sunlight.
Holistic Nutrients: Natural vitamins in whole foods are more bioavailable and come with co-factors that aid absorption, unlike isolated synthetic versions.
Balanced Diet is Best: Consuming a wide variety of nutrient-dense foods is the most effective way to meet your daily vitamin requirements naturally.
Synthetic vs. Natural: While synthetic vitamins can address deficiencies, natural sources offer a complete nutritional package, which can lead to better absorption and utilization.

Photosynthesis: The Foundation of Plant-Based Vitamins

For many vitamins, the journey begins with photosynthesis in plants. Plants are the primary producers of most vitamins, creating these essential organic compounds from basic nutrients in the soil and energy from sunlight. This process not only supports the plant's own growth and reproduction but also provides a rich source of nutrients for humans and other animals when consumed.

For example, the process for producing Vitamin C (ascorbic acid) involves a series of enzyme-driven steps that convert simple sugars like mannose or galactose into the final compound. The efficiency of this pathway can vary, with factors like light intensity directly influencing the plant's ascorbic acid content. Similarly, plants produce beta-carotene as a photosynthetic aid and pigment. Our bodies can then convert this plant-derived beta-carotene into Vitamin A.

Microbial Factories: The Role of Bacteria

Not all vitamins originate from plants. Many B vitamins and vitamin K are synthesized by microorganisms, including the bacteria in our own gut. This microbial activity is a critical natural source of these nutrients. It is estimated that gut microbiota can produce up to 30% of the recommended daily intake for certain B vitamins and vitamin K.

The B-Vitamin Factory in Your Gut

Vitamin B12 (Cobalamin): This complex vitamin can only be synthesized by certain microorganisms, not by plants or animals. Humans obtain B12 by consuming animal products, as the B12 is produced by bacteria living in the animals, or through supplements.
Vitamin K2 (Menaquinone): While green plants produce Vitamin K1, the K2 form is created by bacteria in the gut, which ferments compounds and makes the vitamin available for absorption by the body.
Folate (B9) and Riboflavin (B2): Gut bacteria produce a range of B-group vitamins, with many probiotic species, including Lactobacillus and Bifidobacterium, capable of synthesizing folate and riboflavin.

The Unique Natural Production of Vitamin D

Vitamin D's production is unique among the vitamins as it relies on a direct interaction between our skin and sunlight. When ultraviolet B (UVB) rays from the sun strike our skin, a cholesterol derivative is converted into vitamin D3. This means that, for most people, natural vitamin D production is largely dependent on adequate sun exposure.

Comparison of Vitamin Sources

To better understand the differences, here is a comparison of common natural vitamin sources and their synthetic counterparts.


Feature	Natural Vitamins (from Whole Foods)	Synthetic Vitamins (from Lab)
Source	Plants, animals, bacteria	Chemical synthesis in a laboratory
Bioavailability	Generally higher; absorbed more efficiently due to co-factors	Can be less easily absorbed, as they are often isolated compounds
Associated Nutrients	A complete complex of vitamins, minerals, antioxidants, and enzymes	Isolated chemical structures, lacking the complementary nutrients found in whole foods
Example (Vitamin C)	Found in oranges, broccoli, and peppers, alongside bioflavonoids	Ascorbic acid produced in a lab, without the benefits of bioflavonoids
Processing	Dried, concentrated, and extracted from food sources	Chemically manufactured using inorganic materials and chemical reactions

How Natural Vitamins are Utilized

The bioavailability of naturally sourced vitamins is often superior to their synthetic counterparts because they are delivered within a complex web of other nutrients. For example, Vitamin C in an orange is packaged with bioflavonoids and other antioxidants that aid its absorption and function. This holistic delivery system allows the body to recognize, absorb, and use the nutrients more efficiently. When vitamins are chemically isolated, as in many supplements, they lack these important co-factors, which can impact their efficacy.

The Role of a Balanced Diet

For most people, a balanced and varied diet is the best way to ensure adequate intake of naturally occurring vitamins. By consuming a wide range of colorful fruits, vegetables, whole grains, and lean proteins, you can supply your body with the diverse nutrients it needs. For example, a diet rich in leafy greens provides ample Vitamin K, while citrus fruits are an excellent source of Vitamin C. Relying on natural sources also minimizes the risk of toxicity, which is a potential concern with excessive consumption of high-dose synthetic supplements, especially fat-soluble vitamins like A, D, E, and K.

Conclusion

From the photosynthetic prowess of plants to the industrious work of our gut bacteria and the sun's interaction with our skin, the creation of vitamins is a fascinating natural phenomenon. Understanding where these vital nutrients come from reinforces the importance of a whole-food diet. While synthetic supplements play a valuable role in cases of deficiency, obtaining vitamins from natural sources ensures your body receives a complete package of co-factors and nutrients for optimal health and absorption. Eating a diverse, nutrient-rich diet remains the most effective and sustainable strategy for supporting your body's vitamin needs naturally.

Visit the NHS website for a comprehensive list of vitamins and their natural food sources.

Frequently Asked Questions

Natural vitamins are derived directly from whole food sources like plants, animals, or microorganisms. Synthetic vitamins are artificially created in a lab and are often isolated from the co-factors that naturally enhance their absorption.

Plants produce vitamins through photosynthesis, a process where they use sunlight and soil nutrients to create organic compounds. For example, they convert simple sugars into Vitamin C and produce beta-carotene, which is a precursor to Vitamin A.

Certain bacteria, including the microbiome in our gut, are natural factories for several vitamins. They are the sole producers of Vitamin B12 and synthesize significant amounts of other B vitamins and Vitamin K.

Your body produces Vitamin D when your skin is exposed to sunlight. Specifically, UVB radiation triggers a chemical reaction that converts a cholesterol derivative in your skin into Vitamin D3.

Evidence suggests that natural vitamins from whole foods are often better absorbed and utilized by the body due to the presence of complementary nutrients and co-factors. Supplements can be beneficial for addressing specific deficiencies, but a balanced diet is generally the superior source.

Water-soluble vitamins, such as Vitamin C and the B vitamins, are not stored in the body and must be consumed regularly. Sources include fresh fruits, leafy greens, and whole grains, in addition to production by gut bacteria.

To maximize your intake of natural vitamins, eat a varied diet rich in whole foods, including a wide range of fruits, vegetables, whole grains, and lean proteins. Regular, safe sun exposure is also beneficial for Vitamin D.