Welcome to NeuroTalk:

Please get your actual numbers for the B12.... that range you posted is the old one that goes down too low.

Get me the concentration designation as well... pg/ml or nmol/L? Or whatever it is.

Being vegan is a risk factor for low B12. High folate serum readings usually come with low B12.

The sublingual will work orally...just chew it up and swallow with water. Oral will work but you have to take it on empty stomach with no food for an hour after. First thing in the morning is best.
1/4 tablet of 1000mcg will provide about 3mcg only. The rest is not absorbed.

All those acid blockers are also going to prevent B12 from food from being absorbed, but you don't eat animal sourced foods anyway? Acid is required to break B12 out of protein so intrinsic factor can attach to it. So the issue is not as great for you. I really think you are going to need 5mg methylB12 daily... at least for a while.

Your D3 dose would be based on what level you have at testing.

We have a person, Sally, on our PN forum here who had CFS...so post there, and ask her what she thinks.

http://neurotalk.psychcentral.com/forum20.html