VITAMINS 



235 



Requirements 



Detailed information regarding the riboflavin requirement of man is 

 given in Table 9-3. In general, a daily intake of 1.5-3.0 mg. would 

 appear to be adequate. However, Sherman concludes, from a series of 

 experiments on rats carried out over a long period of time, that the 

 optimum intake, as indicated by a higher level of health and general 

 well-being, may be several times as great as the minimum amount needed 

 to prevent deficiency symptoms. It does not seem likely that harmful 

 effects will result from too large an intake of riboflavin, since excessive 

 doses are rapidly excreted in the urine. 



Amounts of representative foods that would supply approximately 2 

 mg. of riboflavin are: l^/^ lb. lean beef, 2 oz. liver, 1 lb. kale, 1 qt. whole 

 milk, 1 lb. eggs, 13 lb. white flour. 



NICOTINIC ACID (NIACIN) 



Physiological function 



Extreme deficiency of nicotinic acid produces a disease in man known 

 as pellagra. This disease is characterized by roughness and pigmentation 



Courtesy of J. M. Ruffln, D. T. Smith, and The Southern Mediwl Journal. 

 Fig. 9-8. Typical dermatitis of pellagra. 



