Vitamin K Requirements of Adult Dogs and the Influence of Bile on Its Absorption From the Intestine

Abstract

Dogs in which the bile is shunted through the kidney by a cholecystnephrostomy, thereby deprived of bile in the intestines, develop a severe hypopro. thrombinemia because of faulty absorption of natural vit. Ki In such animals 0.5 [mu]g. of vit. Ki/kg. body wt./day given intraven. is required for a normal prothrombin level. When 0.25 [mu]g. was administered, the prothrombin concn. remained 50% of normal. Almost no vit. Ki was stored with a 0.5 [mu]g. daily dose since the prothrombin dropped abruptly 24 hrs. after discontinuing vit. K1. When large doses of bile were given (5 ml./kg. body wt. daily) which approximates the amt. physiologically formed, the prothrombin concn. became normal; little vit. K was stored, as shown by the prompt and rapid drop in prothrombin after stopping the feeding of bile. Water soluble compounds such as 2_methyl_ 1, 4-napthoquinone, given orally in small doses, rapidly corrected the hypoprothrombinemia in the absence of bile. Although the maintenance dose of vit. K1 is extremely small, the absorption in the intestine from the food is equally limited, thus explaining the ease with which avitaminosis K can occur.