I had a vitamin b-12 deficiency as a child and had to take it as a liquid daily,I had lost clumps of hair. Today I went to the doctor and she told me I looked like I had a b-12 deficiency. When I asked her what she meant she said she noticed places on my face that were dry and red around the edges of my mouth. She told me to get a bottle of 1,000 mcg and take it every day for a couple of months and see if it goes away. I went to walmart and all they had was the 2500 or 5000 sublingual. Is this too much or is it water soluble? She didn't say to get the sublingual but I know from the past that I had been told many years ago that I didn't absorb it through the GI tract.