Pea Shoots Grown in Aeroponic Mist Deliver a Full Day's Vitamin B12

John Innes Centre

Vitamin B12 is one of the most structurally complex nutrients in existence. Plants do not make it. Only bacteria do. Humans get it almost exclusively from animal-derived foods - meat, fish, eggs, dairy. For the growing number of people eating vegetarian, vegan, or flexitarian diets, B12 supplementation is essentially mandatory, because deficiency can cause anemia, neurological problems, and cognitive impairment.

But what if a handful of salad greens could deliver your entire daily requirement?

A research team from the John Innes Centre, the Quadram Institute, the University of Bristol, and indoor farming company LettUs Grow has done exactly that. By growing pea shoots in an aeroponic system that delivers B12 directly to the roots, they produced a salad crop that exceeds the recommended daily allowance of the vitamin in a single 15-gram serving. The research is published in Communications Biology.

Misting roots with the most expensive vitamin

The method uses aeroponics - a technique where plant roots hang in air and receive nutrients via a fine mist rather than being submerged in soil or water. The researchers added cyanocobalamin, the most widely available and bioavailable form of B12, to the nutrient mist. During an eight-day cultivation period, the pea shoot roots absorbed the vitamin and transported it through the plant's vascular system into the leaves.

The result: leaves accumulated more than enough B12 to deliver the recommended daily allowance in just 15 grams of plant material - roughly a small handful of pea shoots.

The approach works because B12 is not being synthesized by the plant. The plant is simply acting as a delivery vehicle, absorbing the pre-made vitamin from its root environment and storing it in its tissues. Professor Antony Dodd, a group leader at the John Innes Centre and corresponding author, described pea shoots as literal sponges for B12.

Surviving the shelf and the stomach

Two practical hurdles had to be cleared for the concept to have commercial potential. First, the B12 content had to persist through cold storage - the period between harvest and sale when packaged salad crops sit in refrigerated conditions. The team confirmed that it did.

Second, the vitamin had to survive digestion. Simulated human digestion experiments conducted at the Quadram Institute confirmed that the B12 in the fortified pea shoots is accessible to the digestive system, meaning the nutrient would likely pass into the bloodstream when eaten.

These are not trivial findings. A fortified crop that loses its nutritional benefit on the shelf or in the gut would be scientifically interesting but commercially pointless.

Less than one penny per bag

B12 is the most expensive vitamin on the market, costing up to 20,000 pounds per kilogram - roughly one-third the price of gold. About 90% of the world's supply is produced in China. The molecular complexity of B12 makes traditional chemical synthesis impossible; production relies entirely on bacterial fermentation.

Despite this, the team estimated that the additional cost of adding B12 to bags of pea shoots could be less than one penny per bag. The aeroponic method allows precise control over how much of the expensive vitamin is used, minimizing waste.

Jack Farmer, Head of R&D at LettUs Grow, noted that this is the first time the enhanced yield potential of aeroponics has been combined with B12 fortification in a way that can be scaled to commercial volumes.

Hidden hunger and the supplement problem

The project addresses what nutritionists call hidden hunger - micronutrient deficiencies that occur even when people consume enough calories. An estimated 6% of the UK population is B12 deficient and a further 44% may have insufficient levels, though many people are unaware of their status. Globally, insufficiency is common, particularly in populations consuming few animal-derived foods and among older adults.

Tablet supplements are widely available but have drawbacks: they are easily forgotten, less effective when taken without food (because eating releases enzymes required for absorption), and many people simply prefer getting nutrients from whole foods rather than pills.

The term hidden hunger also applies to nutritional deficiencies that may occur in people taking appetite-suppressing drugs - a growing population given the rapid adoption of GLP-1 receptor agonists for weight loss.

Pea shoots first, other crops next

The researchers believe the approach will work beyond pea shoots. Any rapid-cycling salad crop grown in an indoor farming environment could potentially be fortified using the same technique. The team is now investigating commercial delivery methods and adapting the technique for use in both vertical farms and horticultural glasshouses.

What is still unknown

The study demonstrates proof of concept, not clinical validation. The simulated digestion experiments suggest the B12 is bioavailable, but no human feeding trial has been conducted. Whether the fortified pea shoots actually raise B12 blood levels in deficient individuals - and by how much - remains to be tested.

The eight-day cultivation period and aeroponic setup are specific to controlled indoor farming environments. Whether the method can be adapted to less controlled settings without compromising B12 uptake is an open question.

Shelf-life testing confirmed B12 persistence through an extended cold storage period, but the exact duration and conditions were not detailed in the available information. Commercial supply chains vary, and real-world storage conditions may differ from laboratory simulations.

And while the cost estimate of less than one penny per bag is encouraging, it does not account for the full costs of modifying existing indoor farming operations to incorporate the fortification process.