160 VITAMIN D GROUP 



D. THE VITAMINS D 

 1. Occurrence and Origin 



In contrast to the almost universal occurrence of provitamin D, vita- 

 min D itself is very limited in its distribution. i^- In the vegetable kingdom 

 it is especially rare and never found in high concentration. Occasional 

 specimens of coconut oil show antiricketic activity, but the potency here 

 is not natural; it is man-made in the primitive process of drying the copra 

 under the sun. It is historically interesting to note that what was probably 

 the first therapeutic use of an irradiated material was made a century ago 

 by Thompson,"^ who, writing on the anemia of tuberculosis, stated that 

 "the use of almond-oil and of olive-oil was not followed by any remedial 

 effect, but from cocoa-nut oil results were obtained almost as decided as 

 from the oil of the liver of the Cod ..." 



Yeast normally never contains vitamin D, but it can be activated to a 

 potency of 10,000 I.U. per gram by exposing it in powdered form to sun- 

 light under controlled conditions."* Clover hay when cured in the dark is 

 inactive, but when cured in the sun it acquires a slight antiricketic activ- 

 ity."^ Cocoa shell, as obtained from fermented beans dried in the sun, has 

 been reported to contain 28 I.U. of vitamin D per gram, part of which may 

 have originated in the surface fungi known to be present."^ The antiricketic 

 activity of ergot"^ is probably due to something other than vitamin D, 

 because the active substance cannot be extracted from the unsaponifiable 

 fraction with petroleum ether. 



Marine vegetation being the ultimate food of fishes, much interest at- 

 taches to the possible occurrence of vitamin D in the plant life of the ocean. ^ 

 Leigh-Clare"^ observed that the marine diatom, Nitzschia closierium, fails 

 to effect any genesis of vitamin D, when cultured under conditions of maxi- 

 mum insolation. Drummond and Gunther"^ found little or no vitamin D 

 in mixed phytoplankton taken from the ocean. Johnson and Levring^^" 



i« E. P. Daniel and H. E. Munsell, U. S. Dept. Agr. Misc. Publ. 275 (1937); L. E. 



Booher, E. R. Hortzler, and E. M. Hewston, Vitamin Values of Foods. Chemical 



Publishing Co., Brooklyn, 1942. 

 143 T. Thompson, Proc. Roy. Soc. (London) 7, 41 (1854). 

 "" O. N. Massengale, C. E. Bills, and P. S. Prickett, /. Biol. Chem. 94, 213 (1931); 



C. E. Bills, U. S. Pat. 1,877,382 (1932). 

 "6 H. Steenbock, E. B. Hart, C. A. Elvehjem, and S. W. F. Kletzien, /. Biol. Chem. 66, 



425 (1925). 

 "6 A. W. Knapp and K. H. Coward, Analyst 59, 474 (1934). 

 1" E. Mellanby, E. Surie, and D. C. Harrison, Biochem. J. 23, 710 (1929). 

 "8 J. L. Leigh-Clare, Biochem. J. 21, 368 (1927). 

 1" J. C. Drummond and E. R. Gunther, Nature 126, 398 (1930); /. Exptl. Biol. 11, 



203 (1934). 

 150 N. G. Johnson and T. Levring, Svenska Hydrograf.-Biol. Komm. Skrifter, Ser. 3, 



1, No. 3. 7 pp. (1947) [C. A. 45, 236 (1951)]. 



