Weaning rats were divided into three groups. The first group were fed on a synthetic diet deficient in riboflavin. The second group were fed on the same diet but supplemented with riboflavin, and the quantity of the ration was limited to that of the paired animal in the first group. The third group were also on the riboflavin supplemented diet, but fed ad libitum.It was found that anorexia rapidly developed in the deficient animals and thus caused retardation of growth. However, the appetite was quickly restored as soon as riboflavin was supplied. From the results obtained with the pair feeding method, the growth of the deficient animal is somewhat less than the paired control.There was no effect of riboflavin deficiency on nitrogen equilibrium of the rats and on storage of protein in the liver. There was a slight decrease of ammonia nitrogen excretion in the urine during riboflavin deficiency. Slight increase of urinary amino nitrogen was observed only in the early stage of deficiency.

Weanling rats were placed on ribofiavin deficient diet containing 10 and 20% casein. After the cessation of growth and the development of symptoms of ariboflavinosis, the rata were divided into four groups and were fed the deficient diet supplemented with 0.5, 1.0, 2.0 and 4.0 mg of riboflavin per kg of diet. The animals were housed individually in raised bottom cages. Observations were made on the animal for food intake, growth rate, nitrogen and riboflavin contents of the liver and the urinary excretion of riboflavin. In one experiment, the activity of the liver xanthine oxidaae was also determined.The result shows that 2.0 mg riboflavin per kg of the diet is required for maximum growth rate and food intake, whether the dietary protein level is 10% or 20%. However, at the above level of riboflavin, there is a high urinary excretion of the vitamin when the dietary protein is at 10%. With a 20% casein diet, this phenomenon can only be observed with a higher vitamin supplementation level, i. e. 4 mg/kg of the diet.There is no difference in the riboflavin content of liver among different groups of rats fed with 10% casein diet, however, it increases with the increasing amount of riboflavin supplementation when the casein level is at 20%. At the lower level of vitamin supplementation the riboflavin content in the liver of rats on 10% casein diet is higher than that of the animals on 20% casein or 10% egg albumin diet. The activity of xanthine oxidase varies with the quantity and quality of the protein, and does not depend on the riboflavin content of the liver.The nitrogen content of the liver is independant of dietary riboflavin.

Jujube(Zizyphus vulgaris Lam)is a popular fruit in North China. The fruit is mainly marketed after dehydration. However, there are no less than twenty rarities sold in Peking while fresh during the months of August and October.The ascorbic acid content of 16 varieties of the fresh fruit has been determined. The values found are all above 300 mg per 100 g of edible portion—mostly between 400-600 mg, the highest being above 1,000 mg. It is certainly worth noting that, as a class of ordinary food, Jujube has the highest ascorbic acid content.As the fruit ripens, i. e. the colour turns from green to red and the texture changes from hard to soft, its ascorbic acid content decreases. When the sample was stored at 0-4℃ for about one and a half months, the fruits which remained hard lost about 10％ of its ascorbic acid; when the fruit had become somewhat soft, the amount of ascorbic acid decreased drastically and the dehydro-form increased correspondingly while the total amount remained practically unchanged.Experiment with human subjects indicated that the utilization of the ascorbie acid of Jujube is 86.3-93.0％ of the pure vitamin.