The Effects of Vitamin B12 and Liver Extract on the Utilization of Carotene by the Rat

It is well established that a deficiency of vitamin B12 has a very deleterious effect on growth. It has been reported that with high levels of protein vitamin B12 deficiency may be fatal. This seems to indicate that vitamin B12 plays a fundamental role in the proper utilization of proteins in the normal mammal. Vitamin B12 has been given clinical tests which have proven its effectiveness. Vitamin B12 promotes blood regeneration and protects the patient from degeneration of the nervous system. It is one of the chemicals known to relieve degeneration of the nervous tissues in pernicious anemia. It brings about an increase in the number of red blood cells, platlets, and hemoglobin. Vitamin B12 also relieves subacute degeneration of the spinal cord in pernicious anemia and causes an increase in appetite. Like most vitamins, not too much is known about the role of vitamin B12 in the metabolic process. Vitamin B12 is water soluble and is absorbed through the walls of the intestine into the blood stream. In contrast to vitamin A, the greatest storage of vitamin B12 in animals has been found to be in the kidneys. The liver, heart, small intestine, and muscle, contain no appreciable amount of the vitamin. One of the oldest vitamins discovered and one of the newest vitamins discovered have been briefly discussed. Recent data from the literature concerned with missing factors or factor in the U. S. P. vitamin A-free diet suggested that a study should be made concerned with the effect of vitamin B12 on vitamin A and carotene metabolism. Liver extract, rich in vitamin B12, was also included in this investigation