406 THE BIOCHEMISTRY OF B VITAMINS 



with the time at which urinary thiamine disappears may provide a means 

 of assessing the thiamine requirement from urinary studies. It is further 

 apparent that brain tissue seems particularly able to preserve its thiamine 

 content in periods of thiamine deficiency. 



Riboflavin Deficiency. Riboflavin deficiency was first recognized in 

 man about 1935, although experimental deficiencies in a number of 

 animals had been produced considerably before this time. The vast 

 majority of cases of ariboflavinosis seem to be associated with other 

 deficiencies, characteristically pellagra, but a sufficient number of cases 

 of noncomplicated deficiency have now been observed to indicate that 

 the affliction is a rather common and distinct clinical entity. 00 Whereas 

 there is little to indicate its extent, it seems apparent that ariboflavinosis 

 is relatively common in the southeastern United States, in the Orient, 

 and among native populations in the West Indies. The major cause of 

 riboflavin deficiency so far as is known is an inadequate intake, and corn 

 and polished rice are low enough in riboflavin to insure a deficiency if 

 some other high riboflavin source is not incorporated into the diet. 



The symptoms of ariboflavinosis in man principally involve the mouth, 

 tongue, nose, and eyes, although general body weakness and dermatitis 

 may also occur. 61 Primarily there is an inflammation of the tip and 

 margin of the tongue (glossitis), and lesions at the muco-cutaneous 

 juncture of the mouth with the development of painful fissures. 02 There 

 is an increased redness of the lips, but a pallor to the mucosa, and 

 a scaly, greasy desquamation about the nose and ears. A nasolabial 

 seborrhea and seborrhoic and follicular keratosis of the face is common. 

 Undoubtedly, however, the glossitis is the most prominent symptom, the 

 papillae being large and flattened, and the tongue itself being a reddish 

 purple color, appearing clean, but frequently manifesting fissures. Of 

 equal diagnostic importance, however, is the marked corneal vasculariza- 

 tion and attendant ocular symptoms involving circum-corneal injection, 

 photophobia, burning of the eyes, corneal opacity, and pigmentation of 

 the iris. 63 - 64 There is little doubt that the eye is one of the most sensitive 

 organs of the body to riboflavin deficiency. Out of 47 cases of ariboflavin- 

 osis studied by Sydenstricker et al. 05 six had cataract. 



Ariboflavinosis is identical with an affliction of children long known in 

 the southern United States as "perleche." The symptoms of ariboflavinosis 

 generally respond promptly to riboflavin administration, but only in 

 patients with teeth does the cheilosis disappear. Ariboflavinosis in 

 edentulous patients presents certain unique problems, therefore, with 

 regard to successful therapy. 66 Ariboflavinosis is common in many parts 

 of Africa, and in Nigeria it is said to be present in 16 per cent of the 

 adult population. A syndrome also seen in Africa in which about 50 per 



