vitamin tablets may help but there may be side effects note the funny colour of urine after taking vitamin tablets... that's the same for all western medicine indeed...
it's better to take more fresh fruit besides, not all veggie can be eaten raw but never let them be overcooked at least avoid bbq and say no to charred food
not at all >>補充維他命B群. but i don't think it's necessary 芽菜、麵豉、海帶、慈菇 etc contain Vit B12 actually Vit B12 would be easily denatured by high temperature and people can't take uncooked meat, eggs and raw milk--nothing nothing after cooking... on the contrary, a lot of vegetarian food can be eaten raw
besides, vitamin supplements are artificial human body may not absorb them as well as from natural food...