Riboflavin (E101), also known as vitamin B2 or vitamin G, is an easily absorbed micronutrient with a key role in maintaining health in animals. Like the other B vitamins, it supports energy production by aiding in the metabolising of fats, carbohydrates and proteins. Vitamin G is also required for red blood cell formation, respiration, antibody production and for regulating human growth and reproduction. It is essential for healthy skin, nails, hair growth and general good health, including regulating thyroid activity. Riboflavin also helps in the prevention or treatment of many types of eye disorders, including some cases of cataracts. It may assist bloodshot, itching or burning eyes and abnormal sensitivity to light.
Milk, cheese, leafy green vegetables, liver, yeast, almonds and mature soybeans are good sources of vitamin B2, but exposure to light will destroy the riboflavin in these natural sources. Any excess is excreted in the urine, frequently imparting a bright yellow color. As the human body does not store riboflavin it is thought deficiency is common.
In processed foods it is very likely to have been produced synthetically using genetically modified Bacillus subtilis, altered to both increase the bacteria's production of riboflavin and to introduce an antibiotic (ampicillin) resistance marker.
Riboflavin is yellow or orange-yellow in colour and in addition to being used as a food colouring it is also used to fortify some foods. It can be found in baby foods, breakfast cereals, sauces, processed cheese, fruit drinks and vitamin-enriched milk products as well as being widely used in vitamin supplements.
It is difficult to incorporate riboflavin into many liquid products because it has poor solubility in water. Hence the requirement for E101a riboflavin-5'-phosphate, a more expensive but more soluble form of riboflavin.
