 There are 13 key vitamins required for human health. Vitamin B12 is one of the water-soluble vitamins, the B vitamins. It's unusual in comparison to all the other nutrients in that it's not produced by plants, it's not produced by animals. Vitamin B12 is the only form of nutrient that we get from soil bacteria actually and we don't directly eat the soil obviously but it gets taken up and eaten by animals, things like ruminants, things like cows and they can harbour B12 synthesising bacteria in their guts. And then that's where we get our vitamin B12 source from when we eat a nice juicy steak or some other meat or dairy products. To make vitamin B12 commercially we need a swimming pool of bacteria, a huge quantity of bacteria. The consequence of this is that it's also the most expensive vitamin on the market and it would cost you about £20,000 per kilogram. That's about a third the price of gold. Around 90% of all the world's vitamin B12 is produced in China. If for instance there were tensions this would likely give rise to a crisis in effect a global B12 crisis. Vitamin B12 deficiency was really first identified with people who suffered with what's known as pernicious anemia. It's a non-iron based anemia. It was first shown that to overcome that people had to eat raw liver extracts because liver is a good source of vitamin B12. Milder forms of deficiency can give rise to minor neurological problems that people can appear to have a fuzzy feeling on their tongue. They can have pins and needles. Under really extreme conditions it can give rise to paralysis to death. From a dietary point of view we know that as people move to sustainable plant based and crop based diets the vitamin B12 level is dropping, especially those transitioning from vegetarian to vegan diets are prone to vitamin B12 deficiency. We can estimate that upwards of 5% of the UK population could be defined as vitamin B12 deficient. In other countries such as India for instance where it occurs a much higher level of vegetarianism possibly upwards of 90% of the population have low B12 levels making them either insufficient or deficient for the nutrient. So there are lots of ways that we can get vitamin B12 into our diet. Obviously meat and dairy products but actually things like seaweed are quite good sources of vitamin B12, algae in general and certain kinds of mushrooms. All of those are quite good sources and ultimately it can also be taken through supplements as well. A big thing I've learnt which was a big learning curve for me myself as a plant scientist that I take supplements every day is that I usually take them on an empty stomach, I usually don't take them with food and what's really important with B12 in particular as well as lots of other nutrients is that you need to be eating food for special proteins and factors to be released that enable you to take up B12 effectively into your body. If we can get it into lots of different products that you would eat then that's going to enable more effective B12 uptake. One of the first examples of biofortification would have been during World War II when Robert McCance and Elsie Wilson, pioneers in the study of food data and food composition realised that with the rationing that we really needed to provide extra nutrients in the food and they recommended calcium to fortify the bread and ensure that those key minerals were provided to the population. Our work on B12 and plants, it started serendipitously. I'd been at a rotary meeting, we'd had a talk there about growing daffodils. The person who gave the talk had brought some daffodil bunches which he was selling for charity and I bought a couple of those bunches and brought them back to the laboratory. It just struck me that whilst we put them in a vase that perhaps what would happen if we added vitamin B12 to those daffodils? And so we added some vitamin B12 and after a couple of days cut the daffodils up just to see if the vitamin B12 had moved into the plant. I really wasn't expecting that to happen. It was quite a surprise to actually find that significant quantities of the vitamin could then be detected in the daffodil leaves. Around the same time we were actually approached by a school who were quite interested in doing a science project during their science lab. We'd done our daffodil experiments and we'd shown that the daffodils could absorb vitamin B12 but of course those were using cut stem daffodils. It seemed like an ideal opportunity for us to ask the question can vitamin B12 be absorbed by the root of the plant? What we decided to do with the school was to grow some garden cress. It takes about a week which fitted in with their science lab. With the school we were able to show that the vitamin B12 was absorbed from the root into the leaf of the garden cress itself. A hugely exciting finding this demonstrated to us for the first time that there was a real opportunity to develop plants that were biofortified with vitamin B12. And it was terrific to have school children involved demonstrating and telling them that they had made a basic scientific discovery. You're the first person in the world to know that fact. What we find is that only certain plants were able to absorb vitamin B12 but one of the plants apart from garden cress were garden peas. The great thing about peas is they're just big sponges for lots of vitamins essentially. I'm a plant scientist by training but I'm trying to see how can I optimise how we can get B12 into the plants and how the environment can affect how plants take up this nutrient that they don't naturally need and whether we can manipulate and tailor that. A game changer for doing this is vertical farming. The great thing about these vertical farming systems is that it enables you to have a high level of control over the environment so you can really help tailor uptake. So after we discovered that we could biofortify peas with B12, the next step was to see if we could get them into supermarkets, for example, incorporating them into salad bags. Whether it's getting them into salad bags or actually selling the pea shoots by themselves, it's a great way of incorporating the nutrient into people's diets and the net cost of this should only be about five pence per item. Plant-based diets are much more sustainable and much healthier for the planet. There's an inevitability that we have to adopt more of them and ultimately, as we move more towards sustainable diets, it's very important that we get this question of nutrition addressed when things like vitamin B12 are key to this.