Beware of overdosing on beta carotene (too much carrot juice, especially)-- there have been cases of retina damage. In one case, a patient with stable macular degeneration ( documented as stable for years) received a juicer as a gift and overdid it on carrot juice, and her retina destabilized into geographic atrophy over the next 6 months. I say this as an eye doc, who owns a juicer and loves fresh vegetable/fruit juices! I just don't juice massive quantities, and I use as a guideline only consuming the juice of as much of the veg/fruit as I would consume by chewing.