I am realising that I need to be more aware of the vitamin B12 content of my foods. This vitamin is not produced by animals (or plants) even though it is a crucial requirement for cellular metabolism, in particular neural health and red blood cell production. Deficiency or inability to absorb B12 can have both physical and mental health symptoms, including fatigue and breathlessness, depression and memory loss. Non-human animals ingest B12 from bacterially contaminated foodstuffs and cecotrope products (Google that, but be warned it’s a poop thing), they then by proxy become a source of B12 for humans. I find this essential co-dependency of humans and bacteria like an unwritten love story.
Anyway, as far as I can work out the recommended amount of B12 for an adult is 1.5 micrograms per day, more for pregnant women, and older folk. For anyone on a plant-based diet the scientific jury is out on whether it is present in fermented products like miso, seaweeds like nori and teas like kombucha, so fortified foods are key. Foods that are fortified include alternative milks, tofu, and cereals (check labels), so the humble bowl of cornflakes with a good lashing of chilled almond milk can help. The other option is to take a supplement that contains synthetic B12 and it seems that 2mcg a day is about right. The sledgehammer dosage of 1000mcg in many off the shelf products I am assuming is for anyone with a known deficiency and not for general use – after all it is comparable to about 200 glasses of milk or 23kg of cow and that has to be too much of anything in one day.