Abstract: With the hope of throwing some light on the fate of vitamins B1 and B2 in the body, preliminary experiments have been made to determine whether human urine contains demonstrable amounts of vitamins B1 and B2. As yet there are no satisfactory chemical methods available for these vitamins such as are now in use for determining vitamin C. Therefore biological assays for the vitamin B1 and B2 content of the urine were made by the rat feeding technique. Since it was impossible to fractionate the urine in any way without loss of vitamin, the 24 hour urine samples were concentrated by vacuum distillation and dried in vacuo over sulphuric acid. The dried and powdered urine was thoroughly mixed with one part by weight of sucrose and one-half part by weight of Crisco, and fed to rats on a basal diet in quantities equivalent to 1/25 of the daily 24 hour urine output. In the test for vitamin B1 the basal diet was supplemented with 500 mg. of autoclaved yeast. For the vitamin B2 experiments the source of the vitamin B1 was an extract of rice polishings made according to Rosedale. The rats were fed the urine preparations after a depletion period in which the weight had become stationary for 3 weighing periods of 2 days each. The urine used for these experiments was collected from 3 normal subjects who ate a weighed amount of a well-balanced diet of 2750 calories per day and which, according to present knowledge, contained adequate amounts of vitamins B1 and B2. The urine from one patient with untreated pellagra was also collected. The results (Table I) indicate that the amount of urine equivalent to 1/25 of the daily output of a normal subject contains demonstrable amounts of vitamins B1 and B2.
Publication Year: 1935
Publication Date: 1935-04-01
Language: en
Type: article
Indexed In: ['crossref']
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Cited By Count: 14
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