VI. EFFECTS OF DEFICIENCY 241 



the trabeculum, with or without minimal changes at the chondro-osseous 

 junction hi the form of localized defects of cartilage matrix calcification. 

 Such cases show no change clinically or roentgenologically, and may or may 

 not show changes in the blood calcium or inorganic phosphorus. In contrast, 

 the process ma}^ be so severe that the bones are almost translucent and 

 difficult to differentiate on x-ray examination from the surrounding soft 

 parts. 



Since endochondral ossification ceases with the closure of the epiphysis, 

 deficiency of vitamin D in older people results only in shaft or diaphyseal 

 changes, and the disease characterized by this process is called osteomalacia. 

 Pathologically, we see only the superabundance of osteoid around the 

 trabeculae and a certain amount of osteoporosis. All the complications of 

 soft bones, which we have already described, can then occur. Severe osteo- 

 malacia occurs rarely in the western world except during exceptional times 

 of great stress. An endemic of this disease occurred in Germany during the 

 allied blockade in the first world war and in the subjugated countries 

 subjected to German genocide methods during the second world war. It is 

 sometimes seen following dietary restrictions either self-imposed or im- 

 posed as a therapeutic measure. It also occurs in India, in Japan, and in 

 northern China, among women, w^here prolonged lactation, with its drain 

 on the calcium reserves, may result in a negative calcium balance. It also 

 occurs among women of the higher classes, who practice purdah and are 

 therefore kept confined indoors away from the sun.'^- 



At the epiphyseal end of the bones where the process of endochondral 

 bone formation normally results in elongation of the bone, rickets mani- 

 fests itself by a disruption of the orderly processes which we have already 

 described for that area.'^''' The progressi\'e steps in that disruption may be 

 listed as follows: 



1. Failure of calcium salt deposition in the cartilage matrix. 



2. Failure of the cells to mature, making them impervdous to invasion 

 and therefore leading to their accumulation rather than their destruction. 



3. Compression of the proliferating cartilage cells. 



4. Elongation, swelling, and degeneration of the proliferative cartilage. 



5. Abnormal pattern of invasion of the cartilage by tufts of capillaries. 

 There is some difference of opinion as to what is the very first change 



from normal when the child is depri\'ed of N'itamin D. Park believes that 

 failure of calcium deposition in the matrix is the first deviation (Figs. 18 

 and 19). Because of this failure, the guiding influence^ of the calcified matrix 

 is absent when the inxading blood vessels ap})roach, and these vessels, 



" A. F. IIoss, Rickets Including ( )st(M)mal,icia and TclaiiN-. Lea and Fel)i{ier, Phila- 

 delphia, 1029. 

 " E. A. Park, Haruey Lechires 157 (1938-1939). 



