VITAMINS AND THEIR OCCURRENCE IN FOODS 



By ELazel E. Munseu. 

 Nutrition Chemist, Washington, D. C. 



INTRODUCTION 



The first vitamins were discovered less than 3 decades ago, but 

 since then an ahnost phenomenal number of substances has been 

 classified in this nutritionally important group. A complete listing 

 at the present time would include as many as 40 or more and there 

 are indications of the existence of still others. 



The presence of vitamins in foods was recognized from observa- 

 tions of the almost spectacular effect certain foods have on growth, 

 function, and general well-being of the body. For centuries it had 

 been known that the juice of limes or lemons would prevent or cure 

 scurvy, but there had never been an adequate explanation of this 

 relation. Wlien it was demonstrated that a substance in the outer 

 coating of the whole rice grain would cure or prevent the disease 

 known as beriberi, and that butter and egg yolk contained a sub- 

 stance required for growth and for the prevention of a peculiar type 

 of inflammation of the eye, it became apparent that foods contain 

 certain substances other than protein, carbohydrate, fats, and min- 

 erals which are likewise essential for normal nutrition. 



The substances in foods credited with these properties were dis- 

 tinguished by descriptive terms as the antiscorbutic, antiberiberi, 

 and antiophthalmic factors, respectively, or on the basis of their 

 solubility, as water-soluble C, water-soluble B, and fat-soluble A. 

 When the name "vitamin," from the term "vitamine" originally used 

 for the antiberiberi substance, was suggested for them as a group 

 they were designated vitamin C, vitamin B, and vitamin A. Since 

 the chemical composition of the vitamins became known, several of 

 them have received names related to their chemical structure. Thus, 

 vitamin C is now known as ascorbic acid, vitamin Bi as thiamin, 

 vitamin G or B2 as riboflavin, and vitamin Be as pyridoxine. 



1 Reprinted by permission from The Milbank Memorial Fund Quarterly, vol. 18, No. 4. 

 October 1940. 



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