I couldn't get a vitamin B12 injection, the materials cost of which is less than £1 with no negative side effects, more often than every 12 weeks from my doctor. Despite feeling awful at 8 weeks onwards, to the point of not being able to work, and better again every time I had the injection. I didn't care if it was placebo (although why it would be placebo at 8 weeks but deemed not a placebo at 12 weeks I struggle to…
Curious, why do you need an injection? I thought only vegans had issues with B12, and only if they weren't paying attention to what they ate.
Why it's not absorbed varies, I was tested for pernicious anaemia which is a relatively common cause but I don't have that. That seems to be the end of the line for investigations on the UK NHS, they pretty much just said you can't get it from your diet, it doesn't matter why, so we'll inject it.