Effect of Dietary Conjugated Linoleic Acid on Vitamin A Status of Lactating Rats and Their Offspring.

The absorption and metabolism of vitamin A is linked with that of lipids. It is known that conjugated linoleic acid (CLA) affects the lipid metabolism in growing and lactating animals. In the present study, the hypothesis was investigated that dietary CLA influences vitamin A status of lactating rats and their pups during the suckling period. For this purpose, Wistar Han rats were fed either a control diet (control group, n = 14) or a diet containing 0.87% of cis-9, trans-11 and trans-10, cis-12 (1:1) CLA (CLA group, n = 14) during pregnancy and lactation. Vitamin A concentrations in various body tissues were determined 14 days after delivery in dams and 1, 7 and 14 days after birth in pups, and expression of selected genes involved in metabolism of retinoids was determined in dams. Vitamin A concentrations in liver, plasma and muscle were similar in control and CLA-fed dams. Expression of genes involved in retinoid transport, storage and degradation in liver and adipose tissue in dams was also not different between control and CLA-fed dams. Vitamin A concentrations in milk curd, sampled at d 1, 7 and 14 of lactation were not different between control and CLA-fed dams. Vitamin A concentrations in liver, lung and adipose tissue were also not different in pups from control dams and pups from CLA-fed dams. In conclusion, we show for the first time that dietary CLA has little effect on vitamin A concentrations and vitamin A metabolism in lactating rat dams and, moreover, does not influence tissue vitamin A concentrations in their newborn and suckling pups.