Vitamin B12and Pernicious Anemia

Abstract

Vitamin B₁₂ and Growth Factors for Rats Just as the hen's diet affects the chick's requirement for growth factors, so the diet fed to impregnated rats influences the growth factors needed by the litters. When weanling rats of depleted dams are fed casein extracted with hot alcohol they fail to grow.⁷⁹ The growth factor is found in commercial casein, in variable amounts in "vitamin-free" casein, and in large amounts in commercial liver extracts. Milk, skimmed milk, cheese, beef and pork muscle contain this factor. Egg yolk contains variable amounts of the factor, depending on the hens' diet.⁸⁰ Although the . . .