678 X. \nTAMixs d 



I.U./IOO lb. body weight."^ Harris and co-workes'^i found that 0.82 

 I.U. 'g. dry food was as satisfactory for foxes as it was for minks. •^'- 



{2) In Man 



The same factors which affect the requirement of \-itamin D in animals 

 also apply to human subjects. It is kno%Mi that the ^^tamin D is especially 

 necessary in infancy during the period of growth. If insufficient \-itamin 

 D is present in the infant's diet, rickets is hkely to develop. On the other 

 hand, in older children and adults, when growth is slower, vitamin D 

 deficiency has not been demonstrated. 



According to the recommended daily allowances of the Food Committee 

 of the National Research Council,^' the requirement for infants and for 

 young children is estabhshed as 300 to 400 I.U. day when the calcium 

 intake is adequate. Similar figures are proposed for adults, except that 

 to maintain pregnancy and lactation, the suggested amount required is 

 doubled (800 I.U. 'day). It is recognized that, in the case of an adult 

 man spending a reasonable amount of his time out of doors, no supple- 

 mentary vitamin D may be required. For a further discussion of \-itaniin 

 D requirements in man, the reader is referred to the section by Ivramer and 

 Kanof*** in Sebrell and Harris, The Vitamins. 



7. Hypervitaminosis D 



The first report that \-itamin D may be toxic in large doses resulted 

 from the use of a product kno^\^l as Vigantol, which was first prepared 

 by the I. G. Farljenindustrie.^ ^ This compound contained a toxic 

 product, toxisterol, along ^\ith ^^tamin D. It was given its name by 

 Laquer and Lin-sert.*^^ Windaus and co-workers,^ and Hoyle'^^ found 

 that, when \itamin D was moderately over-irradiated, a toxic property 



»' L. E. Harri.«. C. F. Bassett. and C. F. Wilke. ./. SulrUion, 4-3. 153-165 (195n. 



»' C. F. Bassett, L. E. HarrU. and C. F. Wilke. J. Sutrition, 44, 4,33-442 0951 ). 



*' Anon_\Tnous, Recommended Dietary AUoirance.s, Xat. Research Council, Publ. .Vo. 

 302, Washington, li».>5. 



** B. Kramer and A. Kanof, Vilamin D. Group. VIII. Requirements. B. of Human 

 Beings, in W. H. Sebrell and R. S. Harris, The Vitamins, Vol. II, Acad. Press, New York, 

 1954. pp. 257-266. 



»* I. G. Farbenindu.'strio. Brit. Patent No. 296,093 (Nov. 15, 1928). 



» J. Y John.son (to I. G. Farbenindvistrie), Brit. Patent No. 316,803 (Sept. 25, 1929); 

 I. G. Furbenindustrie, German Patent, No. 499,.524 (Aug. 28. 1930). 



»■ E. Laquer and O. Linsert, Klin. Wochschr., 12, 75:i-754 (1933). 



** A. Windau.', A. Liittringhaus, and P. Basse, Xachr. Ges. Wiss. Gollingen, Math, 

 physik. Kla.ise, III, 150-159 (1932). 



»» J. C. Hoyle, J. Pharm., 40, 351-372 (1930). 



