I am wondering what the relationship is between Ferritin and B12. Is it possible to have a normal Ferritin level but a low B12? At my last blood test a month ago, my Ferritin level had increased to normal and my B12 level was low normal. I am still really tired so have had bloods taken again today. If my Ferritin is going up does it automatically mean my B12 will go up as well?