Thanks. I always had good results, but some time ago I had to take a series of medications, which my stomach didn't like. They are the culprit according to my sis's hausband, who's a medical doctor (the NHS GP blamed it on my vegan diet, but that's probably because "vegan" was the only word in my self-assessment that sounded the same in Urdu). They treat it with injections here. At least that's the intention, because NHS is incapable of managing their electronic system for prescribing and delivering drugs (I get a notification that the injection was delivered to the designated pharmacy, but when I call them/go to pick it up, the injection either is there or it isn't/no sign in their system, quantum state). So I got a battery of nasal and oral sprays (the highest doses indeed ordered from the US - you've got more of everything there!). I reasoned that oral supplements might not be absorbed well by my irritated guts, but maybe I'm wrong... I will get some capsules too. Apparently B12 is impossible to overdose. And it gives me an incredible energy boost!
Previously I felt so weak that I sometimes got stuck in bed for the whole day.
Sorry, I like to complain about NHS (I'm no longer supporting Labour, so I am allowed).
Vitamin D deficiency is a problem in women as we age (35+) from what I've read. I'm keeping an eye on it too.