I have to chime in and say that I had some similar symptoms to you in the beginning of my health journey.

Both B12 and Vit D were low and I treated them and felt better but not good enough.

Then I also discovered that I was very iron deficient. I mention this because like B12, Iron is a large molecule and hard to absorb. I feel even better when I supplement with all 3 B12, Vit D and Iron.

IF you are iron deficient one of the symptoms does include parathesias.

Be sure to ask your doc for a bllod test of iron serum, TIBC and ferritin.

If you are iron deficient the best thing I have found is the once a day prescription Repliva. Much less stomach upet.

Keep us posted.