“…Wokes, Badenoch and Sinclair stress the extremely slow fall of vitamin B 12 serum levels in Vegans, which reach their lowest levels after about seven years, rise again slightly and become established at a low level after wards. If vegetarians who abstain from animal protein eat large amounts of leaf vegetables, they might get acute B12 deficiency through excess intake of folic acid (Lowther, 1954). It is known that B12 deficiency states develop sub-acute combined degeneration when treated with folic acid.…”