IX. EFFECTS OF DEFICIENCY 193 



of body weight per day is effective in controlling hydroxyphcnyluria, and 

 a definite but siiboptimal response is procured with 4 mg."" In Woodruff's 

 study the three patients studied in whom no effect was produced received 

 iietween 1.3 and 2.2 mg. per kilogram per day. In cases reported by other 

 workers the effective doses varied between 3 and 13.7 mg. per kilogram 

 of body weight per day. Woodruff"" has also observed that in megaloblastic 

 anemia of infancy as little as 0.2 mg. of PGA will effect a maximal hemato- 

 logical response. These experiments dramatically illustrate the fact that 

 vitamin reciuirements for different functions may vary and that re(iuire- 

 meiits can be enormously altered by imposing a metabolic load on the orga- 

 nism. 



b. Relation of PGA and Ascorbic Acid in Megaloblastic Anemia 



The role of PGA in megaloblastic anemia of infancy provides additional 

 information on the relations between ascorbic acid, PGA, and vitamin Bi- . 

 The effectiveness of PGA in curing the megaloblastic condition of the bone 

 marrow was demonstrated by Zuelzer and Ogden."'- May et aZ.'"^ has re- 

 \-iewed this work and focused attention on the role of ascorbic acid defi- 

 ciency in the etiology of this disease. In megaloblastic anemia of infancy 

 the most frequent symptom is a megaloblastic bone marrow. Examination 

 of the peripheral blood alone will not always suffice for the recognition of 

 this syndrome because the circulating red cells are not always macrocytic 

 and not all macrocj^tic anemias are associated with megaloblastic marrow. 

 The majority of the cases occur in patients between the ages of 5 and 12 

 months, which corresponds roughly to the period of most frequent develop- 

 ment of clinical signs of ascorbic acid deficiency. Megaloblastic anemia has 

 been frequentlj^ reported as a complication of scurvy. 



May and co-workers^"^ experimentally reproduced the condition of 

 megaloblastic anemia of infancy in monkeys on milk diets used in infant 

 feeding. Their saUent experimental findings are: 



1. When ascorbic acid is provided, the diets do not lead to megaloblastic 

 anemia. 



2. If vitamin C is inadequate, all the diets result in megaloblastic anemia. 



3. Megaloblastosis of the marrow is quickly eliminated by PGA with- 

 out addition of vitamin C. 



4. Ascorbic acid alone might permit gradual return of the marrow to 

 normal. 



5. \'itamin B12 administered intramuscularly does not significantly alter 

 the megaloblastic ])one marrow within 72 hours. 



'»2 W. W. Zuelzer and F. X. Ogden, Am. J. Diseases Children 71, 211 (1946). 

 '"' C. D. Ma}-, E. X. Xelson, C. U. Lowe, and R. J. Salmon, Am. J. Diseases Children 

 80, 191 (1950). 



