Riboflavin is a water-soluble vitamin, which is involved in vital metabolic processes in the body and is necessary for normal cell function, growth, and energy production. Small amounts of riboflavin are present in most animal and plant tissues. Healthy individuals who eat a balanced diet rarely need riboflavin supplements. Especially good dietary sources of riboflavin are milk (and other dairy products), eggs, enriched cereals/grains, meats, liver, and green vegetables (such as asparagus or broccoli). Intake may be lower in vegetarians compared to non-vegetarians. Riboflavin is often used as a tracer of medication compliance in the treatment of patients with alcohol dependence, mental disorders, and other conditions. Urinary riboflavin levels may be measured in order to determine the level of compliance.