Eating the Dirt for Vitamin B12

Bacteria are the only true sources of Vitamin B12

Are you taking a synthetic B12? Why?

Vitamin B12 originates in soil bacteria. All plants, animals, and humans ultimately depend on soil-derived microbes to obtain it — directly or through the food chain. No higher organism makes its own B12. Soil is the original source for every species.

A lifetime supply of B12 would fit onto the head of a pin with room to spare. B12 supplementation is one of the pharmaceutical/nutraceutical industry's most lucrative and unnecessary.

Soil is the Original Source of Vitamin B12 for All Species

Vitamin B12 (cobalamin) is not made by plants, animals, fungi, or humans.It is made only by certain bacteria and archaea — and many of these organisms live in soil.

Before industrialisation, chlorinated water, sanitisation, intensive farming, grain processing and antibiotics, soil-based microbes were the primary natural source of B12 for virtually every species on earth.

Here’s how it works across nature:

1. Soil Microbes Are the Only True Manufacturers of B12

• Only a small group of microorganisms have the genes needed to build the cobalamin molecule.

• Many of these bacteria live in soil and sediment, including species of Pseudomonas, Propionibacterium, Rhizobium/Sinorhizobium, Streptomyces, and certain archaea.

2. Plants Don't Make B12 — They Acquire It From Soil Microbes

Plants grown in healthy, microbially rich soil can carry trace amounts of B12 or B12 analogues on their surfaces or in their root zones.Traditionally, animals and humans consumed:

• unwashed or minimally washed produce

• soil-rich root vegetables

• well water with natural microbial content

• ferments made with environmental bacteria

All of which provided real microbial B12 or its usable precursors. Modern sanitisation, bleaching, chlorination and chemical farming have severely reduced these natural exposures.

3. Herbivores Get B12 From Soil, Not Plants Themselves

Cows, sheep, kangaroos, deer and other herbivores do not get B12 from grass.They get it from:

• soil attached to plants they eat, and

• bacteria living inside their own digestive system, many of which originate from soil in early life.

Even ruminants who synthesise B12 in their gut still need cobalt, a soil-derived mineral required for microbes to build the cobalamin molecule.

Without cobalt in soil → the animals become B12 deficient → humans eating those animals would be deficient too.

4. Carnivores and Omnivores Get B12 Second-Hand

Predators obtain B12 from the tissues of herbivores.But the origin is still the same:

Soil microbe → herbivore → carnivore.

Every food chain ultimately traces B12 back to soil bacteria.

5. Humans Historically Obtained B12 the Same Way

Before sterilised environments, humans acquired B12 from:

• soil microbes on wild and garden vegetables

• spring and well water

• fermented foods cultured from environmental bacteria

• incidental soil ingestion from foraging, farming and daily life

• living closely with animals and natural ecosystems

In short:

B12 availability for humans and animals originally depended on direct exposure to soil and soil-based bacteria.

6. Modern Practices Broke the Natural B12 Cycle

• Chlorinated water

• Sanitised, triple-washed produce

• Pesticides and herbicides that destroy soil microbes

• Ultra-processed diets

• Antibiotics and farm chemicals that kill B12-producing species

• Indoor living with minimal contact with earth

All of these reduce the microbial exposures humans had for hundreds of thousands of years.

This is why B12 deficiency is now common even in meat-eaters, and why reliance on supplementation has become widespread.

⭐ Myth vs Fact: Vitamin B12 & Soil

Industry-penned junk science is responsible for much of the confusion. Today, it is easier to prescribe a synthetic supplement than understand the truth in nutrition. Maybe it is time to put this right.

MYTH:

“Vitamin B12 comes from meat and dairy.”

FACT:

Vitamin B12 does not originate in animals at all.B12 is produced only by certain bacteria and archaea, many of which naturally occur in soil, water, and the guts of animals. Animals are middlemen, not producers.

MYTH:

“Humans evolved to get B12 only from meat.”

FACT:

For most of human history, people obtained B12 naturally from:

• Soil bacteria on unwashed vegetables

• Drinking from streams and wells

• Fermented foods

• Living in close contact with soil-rich environments

Modern sanitation, while good for reducing disease, has removed most natural B12 exposure.

MYTH:

“Vegans cannot get natural sources of B12.”

FACT:

In pre-industrial societies, vegans and near-vegans still received B12 through:

• Soil residue on produce

• Naturally bacteria-rich water

• Fermented foods

• Traditional farming environmentsToday, supplementation is usually required not because plants lack B12, but because modern hygiene eliminates bacterial sources.

MYTH:

“Animals produce B12 themselves.”

FACT:

Animals acquire B12 from:

• Gut bacteria (ruminants like cows produce their own internally)

• Soil bacteria absorbed through grazing

• Supplementation, which is extremely common in modern farming

Most commercial livestock today receive manufactured B12 supplements because soil quality has declined.

MYTH:

“Soil bacteria are not significant sources of B12.”

FACT:

Modern research confirms that soil contains diverse B12-producing microbes.Studies show soil acts as a “natural reservoir” of B12 through corrinoid-producing bacteria.

References:

• Lu, X., Heal, K. R., Ingalls, A. E., Doxey, A. C., & Neufeld, J. D. “Metagenomic and Chemical Characterization of Soil Cobalamin Production.” The ISME Journal 14, no. 1 (2020): 53–66. DOI: 10.1038/s41396-019-0502-0. Mendeley+2PMC+2

• Hallberg, Z. F., Alvarez-Aponte, Z. I., Sieradzki, E. T., Pett-Ridge, J., Banfield, J. F., Carlson, H. K., Firestone, M. K., & Taga, M. E. “Soil Microbial Community Response to Corrinoids Is Shaped by a Natural Reservoir of Vitamin B12.” ISME Journal (2024): wrae094. DOI: 10.1093/ismej/wrae094. PubMed+1

• Alvarez-Aponte, Z. I., Hallberg, Z. F., & Carlson, H. K. “Phylogenetic Distribution and Experimental Characterization of Corrinoid Production and Dependence in Soil Bacterial Isolates.” ISME Journal (2024). DOI: 10.1093/ismej/wrae068. Phys.org

• Experimental Biology and Medicine. “Vitamin B12 Sources and Microbial Interaction.” Experimental Biology and Medicine 243, no. 2 (2018): 148-158. DOI: 10.1177/1535370217746612. SEBM