Celia16, .....okay, your reply pushed me to get my B-12 levels. Between 2007-2023(7 tests), my lowest level was 517 in 2014, 1650 in 2023, avg of 813. My test papers says >=200 pg/mL. What does your paper say is the normal range? What level does your neurologist says is best? What level is the highest, that is still ok? I have taken supplements randomly throughout past years, but none for a long time. How fast will the sublingual type show an increase? Thanx for caring enough to take your time to reply. Right now, caring truthfulness, is a much, much more important issue to me, than most people would realize. So, ‼️😇🫂 Shelley