Quest Vitamin B12 is involved in the production of red blood cells and in maintaining nerve insulation. Vitamin B12 can be lacking in the diet of vegetarians and vegans. Ingredients; Vitamin B12 500 æg, Uva Ursi Leaf extract 25 mg (Equivalent to 100mg herb powder). Quest is an independent, innovative, intelligent and responsible manufacturer that strives for continued excellence in which the customers can trust. Quest products have been created to make you feel good. You can choose products as a response to immediate health concerns, for long-term health and well-being, and finally, to support the health and function of your body.