bild

^BVitamin B2 crystals.^b Light micrograph of crystals of riboflavin, or vitamin B2. Riboflavin may be isolated as these orange, water soluble crystals. In the body it forms an oxidation enzyme and, as such, acts as an oxygen carrier to the cells. It also acts as a part of dietary growth factor, forming complexes with other b group vitamins. It is widely available in the diet; rich sources include liver, milk and egg white. Deficiency of vitamin B2 may lead to anaemia, cheilosis, corneal vascularisation and seborrheic dermatitis. Dietary overdose in humans is essentially non-toxic. Magnification x90 at 35mm size. (KEYSTONE/SCIENCE PHOTO LIBRARY/MANFRED KAGE/SCIENCE PHOTO LIBRARY)