Signs of deficiency are dry cracks at the corners of the mouth and eyes that are watery, itchy, and bloodshot. Young children need about 1 mg. Adults need 1 to 2 mg. per day. Unlike many of the other B vitamins, B2 is unevenly distributed amongst the food groups, with the largest contributor being milk and meat. The need for riboflavin is a major reason for including milk, in some form, in your diet everyday.
Most people get half of their riboflavin from milk.
If you don't include dairy in your diet, then a generous serving of dark green leafy vegetables can be substituted. Meat, eggs, whole grains and enriched grains are also god sources of B2. Riboflavin is light sensitive, so food containing it should not be stored in transparent containers. If it is lacking the cells, energy production stops, causing tissue damage throughout the body. The digestive system, skin and nervous system are particularly sensitive because of their rapid cell turnover.