All I can say is B12 is a hell of a vitamin

[Codger]

can i ask if i am eating plenty of eggs and cheese, that should be sufficient b12 right?
i don't really eat liver, shellfish or yeast products.

maybe gonna start on pork liver soon. plenty of pple keep telling me how nutritious it is

I'm not really qualified to say but there are various stats on it. This study shows it's not all that common: http://ajcn.nutrition.org/content/89/2/693S.full

This article is more sensationalist and is pushing that it's much higher but seems to conflate lowish levels (but not deficient) with deficient to produce more startling numbers: https://www.ars.usda.gov/news-event...ficiency-may-be-more-widespread-than-thought/

As for pills not working - AFAIK they work unless you're deficient because of gastric problems, in which case they won't work as well.

Reading those articles bring up an interesting point: "Oddly, the researchers found no association between plasma B12 levels and meat, poultry, and fish intake, even though these foods supply the bulk of B12 in the diet. “It’s not because people aren’t eating enough meat,” Tucker said. “The vitamin isn’t getting absorbed.” It looks as if dairy is one of the best natural foods. Fortified grain products (where they add B12 artificially) are found to work well which indicates that supplements should work too since it's essentially the same thing.

If you're worried about it there are mouth sprays that are supposedly pretty well absorbed. Injections are normally given by doctors for diagnosed B12 problems, rahter than something you have a go at yourself because you've been a bit tired recently.