Carrots are great fodder for juicers, since they can offer all kinds of health benefits like stronger vision and boosted metabolism, which can be condensed down into a convenient liquid.
By juicing carrots, you actually increase the calorie content, which means if your goal is to lose weight you should be careful not to overdo it.
Generally, if you drink a 4oz glass of carrot juice every day, then this is a good amount.