[Vitamin B1 nutritional status of the lactating rat and her litter as a function of the dietary level of thiamine].

Influence of the Dietary level of Thiamin on the Vitamin Nutritional Status of the Lactating Rat and the litter. Seven Groups of female rats which had given birth to the litters of 8 youngs (or litters adjusted to 8 youngs) were fed diets containing respectively 0.5, 1, 2, 4, 8, 16 or 32 mg/kg of thiamin. Eighteen days after littering, the thiamin content was measured in female tissues (blood, liver, carcass) or in those of the youngs (liver, carcass). Besides, the thiamin content in the stomach of the youngs was measured, 3, 7 and 14 days after birth. 1. In the females there are linear or cubic relationships between the thiamin content in the tissues and the log-concentration of the vitamin in the diet. In the liver and the carcass, it seems that the vitamin level in the tissues reaches a plateau when the dietary level is below 1 mg/kg or above 16 mg/kg. 2. On day 7th or 14th the gastric vitamin content (milk) in the youngs gradually increases, as the dietary vitamin supply does, and especially on day 14th when the dietary level of thiamin is 2 mg/kg or higher. 3. In the youngs, the organ thiamin contents markedly increase when the dietary supply rises from 1 to 8 mg/kg. Below 1 mg/kg and beyond 8 mg/kg there is a plateau. 4. These results suggest that the thiamin fixation in the offspring tissues occurs prior to the fixation in the lactating mother. The priority would be proved by the fast increase of the milk content in thiamin during the 2nd week when the vitamin dietary supply rises.