Chronic Riboflavin Deficiency in the Rat. I. Ossification in the Proximal Tibial Epiphysis.

Abstract
The tibias of 6 male rats of the Long-Evans strain born from riboflavin deficient mothers and maintained on riboflavin deficient diets for 3 to 9 months were studied histologically and compared with an equal number of controls reared upon the same diet but with riboflavin added. In the deficient rats the growth of the tibia was retarded and endochondral ossification was gravely impaired. Marked reduction in chondrogenesis and in capillary erosion was characteristic for all degrees of the deficiency. The formation of a thin calcified plate on the diaphyseal side of the epiphyseal cartilage is a finding in consonance with the early arrest of growth. Hematopoietic tissue was replaced by fat in all animals after 144 days on the deficient diet.