Riboflavin is important in the chemical processes by which energy is obtained from food. Deficiencies are rare and usually occur in association with lack of thiamine and nicotinic acid. If the vitamin is deficient the lips and tongue become sore because of inflammation and the eyes become red and painful. Its functions are similar to those of riboflavin. Deficiencies are rare except among those people for whom maize forms the staple diet.
Symptoms are loss of weight and appetite and general ill health.
This is present in many foods, especially whole-grain cereals, meat, liver and vegetables. Deficiencies result in disturbed metabolism which in children can affect growth, but fortunately this is rare. It has been said that extra quantities of this vitamin may be of value in premenstrual tension. This is present only in animal foods, especially liver, meat, eggs, milk and fish. This is present in many foods, especially liver and green leaf vegetables.