Hello, My apologies if this post is redundant--I thought I posted it yesterday, but it seems to have vanished. I was diagnosed with low Vitamin D in April and low B12 (148) in August. I am in the US. I received daily injections for 7 days, followed by 4 weekly injections, and now monthly "forever." I continue to have muscle twitches throughout my body. It's hard to say whether or not they are improving. I saw a neurologist who would like to see my levels at 800. At last check, they were around 600 about 2 weeks after the prior injection, but I had started taking oral B12 (1000 mcg) and Vitamin D3 (2000 IU) daily. My doctor supports monthly injections and I have learned to do them myself. Our current plan is to retest my B12 1 month after the last injection, but having taken the oral B12 and D all along, to try to sort out whether this is an absorption issue or another cause, because I would like to know. The low vitamin D along with the low B12 supports poor absorption, but it is not unusual to have low vitamin D after a New England winter. I'm being told that intrinsic factor is no longer tested, and that a diagnosis of PA is a process of elimination. My question is whether or not the B12 results will be accurate if I've been taking oral B12 for the past month?