I am working on a fanfic of the Martian, where (among other changes) NASA did not arbitrarily decide to send enough multivitamins to last a single astronaut for four years (the equivalent of sending over 8 months worth per astronaut) when the crew was only due to stay 30 days. He has a decent variety of vegetables to grow for food, and will be primarily using hydroponics, so the space available should be sufficient to keep him fed for quite a while, but the vegetables do not provide a source of B12 for him. There is a line in the book that suggests he had earthworms [ETA: this reference was removed from the current version of the book], so I've been trying to figure out if he would be able to grow enough worms with vermicomposting to meet his RDA. He will have enough leftover vegetable matter and other wastes to feed at least a small worm farm, but I have been completely unable to find out how much B12 the worms will provide.
I am looking at composting earthworms, which he needs for producing vermicompost. I've seen a number if sites that say they're 'high' in B12 or that they are a 'good source', and apparently they add B12 to the soil, but the sources I've seen give no actual values. The only source I've found that gave numbers listed "Earthworms" as if it was one species, with a value of N/A for B12, yet distinguished between different varieties of fly larvae. I have not been able to access scientific papers as I lack the funds to join the databases or buy the articles outright.
I am primarily looking at Eisenia fetida (previously foetida) (red wigglers), but Eisenia andrei (red tiger), Lumbricus rubellus (red worms), Perionyx excavatus (blue worms), Eudrilius eugeniae (African nightcrawlers), or Eisenia hortensis (European nightcrawlers) would also work. Even an educated guess would give me something to go on.
