688 PANTOTHENIC ACID 



still be approximately 6 to 7 mg. The widespread distribution of panto- 

 thenic acid in foods undoubtedly guards against a deficiency of this vitamin. 

 The absorption of the vitamin is apparently fairly complete and is not 

 impaired even in such a disease as pernicious anemia. ^^ 



On the basis of the dietary intake of pantothenic acid, the requirement 

 would seem to be about 7 mg. daily. This is lower than the 10 to 12 mg. 

 suggested by Williams.^" 



2. Urinary Excretion and Blood Levels of Pantothenic 

 Acid in Human Beings 



The urinary excretion of pantothenic acid has been measured in man by 

 many investigators,^^*®® and Oldham et al.^^ have determined the fecal 

 excretion. The data from the various reports on urinary excretion are m 

 good agreement and show that on normal diets the excretion ranges from 

 1.3 to 5.3 mg. per 24 hours. The excretion of pantothenic acid is influenced 

 by the intake. The excretion is not altered in elderly people.®'' Oldham et 

 al. have done a very complete study on the excretion of pantothenic acid 

 in urine and feces at different levels of intake, and the data in Table XXI 

 are taken from their report. Approximately 54 to 84% of the excreted 

 vitamin was found in the urine, and 25 to 38 % in the feces. 



Rubin and his associates®^ found that when pantothenic acid was given 

 in the form of pantothenyl alcohol a greater portion of the pantothenic 

 acid was excreted than when administered in the form of calcium panto- 

 thenate. They gave doses of 100 mg. of calcium pantothenate or an equiva- 

 lent dose of pantothenyl alcohol. Their interpretation was that the panto- 

 thenyl alcohol was physiologically more available than calcium panto- 

 thenate. However, I would question this interpretation and would suggest 

 rather that the blood levels may have risen more rapidly following the 

 administration of the pantothenyl alcohol, and that this was associated 

 with an increased rate of excretion. In renal clearance studies, Wright et al.^^ 

 have studied the relation of the excretion of pantothenic acid to the blood 



" C. E. Meyer, I. F. Burton, and C. C. Sturgis, Proc. Soc. Exptl. Biol. Med. 49, 363 



(1942). 

 «o R. J. Williams, J. Am. Med. Assoc. 119, 1 (1942). 

 " H. P. Sarett, J. Biol. Chem. 159, 321 (1945). 



«2 H. G. Oldham, M. V. Davis, and L. J. Roberts, J. Nutrition 32, 163 (1946). 

 63 L. D. Wright and E. Q. Wright, Proc. Soc. Exptl. Biol. Med. 49, 80 (1942). 

 «* M. J. Pelczar, Jr., and J. R. Porter, Proc. Soc. Exptl. Biol. Med. 47, 3 (1941). 

 «5 P. B. Pearson, A7n. J. Physiol. 135, 59 (1941). 



66 H. Krahnke and E. S. Gordon, /. Am. Med. Assoc. 116, 2431 (1941). 



67 V. Schmidt, /. Gerontol. 6, 132 (1951). 



68 S. H. Rubin, J. M. Cooperman, M. E. Moore, and J. Scheiner, /. Nutrition 35, 

 499 (1948). 



69 L. D. Wright, K. H. Beyer, H. R. Skeggs, H. F. Russo, and E. A. Patch, Am. J. 

 Physiol. 145, 633 (1946). 



