VITAMINS — MUNSELL 



265 



Table 2. — Values suggested as expressive of the daily requirement for vitamins A, 



B\, C, D, and riboflavin^ 



• Previously published. Mimsell, Hazel E., Planning the day's diet for vitamin content. 

 Amer. Dietetic Assoc, vol. 15, p. 639, October 1939. 



Journ. 



In summarizing data on vitamin requirements, it seems desirable 

 to give the quantities determined as minimum as well as those con- 

 sidered adequate. In some instances data have been obtained indi- 

 cating that nutritional well-being is enhanced by a diet supplying 

 quantities of a vitamin in excess of that considered adequate. Such 

 quantities have been designated as optimum. 



Studies to determine the requirement of the various vitamins are 

 still in the preliminary stage. It is problematical whether the 

 requirement of any vitamin can ever be expressed with precision. 

 Many factors operate to influence the quantity of each that is needed. 

 Data already at hand indicate that the requirements may vary from 

 individual to individual according to sex, age, size, and activity, and 

 vary in the same individual from day to day depending upon the 

 physiological condition, activity, or environment. 



The material offered in table 2 should be used with certain con- 

 siderations in mind. With the exception of vitamin D the values 

 for the requirement of each of the vitamins represent quantities 

 that may be supplied readily by the use of natural foods. These 

 quantities indicate the daili/ requirement of the normal individual 

 with no allowance made for variation in the vitamin value in dif- 

 ferent foods or losses that may occur from cooking or other processes 

 to which the food may be subjected. 



There is no evidence of harm from the ingestion of vitamins as 

 they occur in foods in quantities considerably in excess of those given 

 as requirements. In planning diets the aim should be to provide 

 foods that will supply at least as much and preferably more than the 

 adequate allowance of each vitamin and several times this allowance 

 in cases where there is indication of a greater need. 



