Good news for vegetarians – plants can be made to absorb B12

Researchers at the University of Kent have discovered that some plants can absorb vitamin B12. The study has been published in the journal Cell Chemical Biology.

Vitamin B12 is unique among the vitamins because it is made only by certain bacteria and therefore has to undergo a journey to make its way into more complex multi-cellular organisms, such as cattle.

Vitamin B12 (also known as cobalamin) is an essential dietary component but vegetarians are more prone to B12 deficiency as plants neither make nor require this nutrient.

The amount of B12 absorbed by garden cress is dependent on the amount present in the growth medium, and the Kent team was able to confirm B12 uptake in cress leaves.

The observation that certain plants are able to absorb B12 is important as such nutrient-enriched plants could help overcome dietary limitations in countries such as India, which have a high proportion of vegetarians.

The researchers grew garden cress containing increasing concentrations of vitamin B12. After seven days growth, the leaves from the seedlings were removed, washed and analysed.

The seedlings were found to absorb cobalamin from the growth medium and to store it in their leaves. To confirm this initial observation, the scientists at Kent then made a type of vitamin B12 that emits fluorescent light when activated by a laser. This fluorescent B12 was fed to the plants and it was found to accumulate within a specialised part of the leaf cell called a vacuole, providing definitive evidence that some plants can absorb and transport cobalamin.