when i was diagnosed i had chronic b12 deficiency on my record but was supplementing hard because i was freaking out, so they ruled out the deficiency in their differential. c'est la vie. to fix my b12 issues i stopped being vegan, went back to omnivore, in the short term took 2000 ucg per day sublingual methylcobalamin, and another good one would be hydroxocobalamin. you won't likely find those in your everyday chemist's. lots of online vendors but in some countries it can be more challenging. long term, now i take a pretty standard b50-complex every day or so, plus aim for red meat (ideally wild game but usually small family farm raised) once a week.
i was all about vit d3 for a while once i got over my early b12 obsession, and took some short term d3 megadoses (about 1 week, on 2 different occasions) followed by 4000 IU per day over a number of years. that just about killed me via mag depletion, because as it turned out i'd also had low magnesium probably as a lifelong deal, lots of status quo stress growing up. i was taking a small amount of mag each day at the same time as d3. pharmacist said no take more and you take half the mag with the d3 and half away. we don't need to go into my year or so of magnesium adventures, you likely can imagine and i don't even know how many times i've told the same story on here anyway! short story, you would probably do well to sort out your mag d3 timing by splitting out your 200mg mag into two 100mg doses.
my background with migraines is there but not terrible, a scant handful of times in my life only. i have had to deal with transient 'scintillating scotoma' a couple times. last time (couple years ago?) i took an extra magnesium glycinate for a couple of days and it cleared up.
we have tons of xp reviewing ppls labs. i have files from around the world (not all in english but i'm usually ok as long as its a familiar alphabet hehe). it usually surprises patients to find that not all 'normal' is created equal. super annoying - should be common knowledge. one day!
there are one or two other nutrients to consider if vegetarian and looking to prevent ms; once you get through the learning curve on b12 and d3 and magnesium that will be soon enough
