A doctor prescribed injectable B12 for nerve therapy, once a week. As a boy, I dreaded getting any vaccination. As a man, the, um, inner boy still yanks the emergency lever at every flu shot, but I calm him quickly, as he's discovered that inoculations are usually painless. Innocuous? A blood test revealed too much B12 later, so I was prescribed tablets, which were also too much and thus every other day I took them. For artists, Cobalt pigments are common, coming in Aureolin yellow, Cobalt blue and at least three hues of purple. Cobalt greens, Cerulean blue in green and red shades. Vitamin B12 is cyanocobalamin, a preparation of cobalt. The vials of B12 are a beautiful purple red. The figure of myself here is B12 out of the vial, a week's worth.