Possible Interaction: Tretinoin and Vitamin A

“Biochemical investigations have shown that the administration of vitamin A acid is associated with elevation of serum levels of retinol and carotene and after high dosage symptoms develop identical with hypervitaminosis A. Several possibilities regarding the mode of action of vitamin A acid are discussed.”

“However, ROL induced significant epidermal thickening (1.5-fold at 1.6% ROL, p < 0.01), similar to RA (1.6-fold at 0.025% RA , p < 0.01), relative to the vehicle.”

“Relative to controls, concentrations of all isomers of RA were higher in calves supplemented with > or = 34,000 of vitamin A daily during the experimental period.”

“The answers to these questions are highly relevant to human health, considering that those with either limited or excessive intake of retinoids/carotenoids during pregnancy may be at risk of obtaining improper amounts of VA that ultimately impact the development and health of their offspring.”

“At present, it is difficult to ascertain why the reported associations differ depending on the compound under study, but there is a clear imbalance in the literature in disfavor of retinol and retinoic acid , which needs to be considered in future human studies.”

“Together they form a codependent complex that facilitates negative feedback maintenance of retinoic acid levels and thus guard against the effects of dysregulated vitamin A metabolism and retinoic acid synthesis.”

“Together these observations demonstrate the importance of vitamin A metabolism in regulating RA signaling during embryonic development in vertebrates.”

“We show that a subset of retinoids strongly stimulates STRA6-mediated vitamin A release from holo-RBP.”

“Previous research in our laboratory showed that retinol inhibited all-trans retinoic acid (ATRA)-resistant human colon cancer cell invasion via a retinoic acid receptor-independent mechanism in vitro.”

“Beyond the ability of vitamin A (VA) and its active metabolite, all-trans-retinoic acid (RA) to restore growth in VA-deficient animals, supplementation with VA and/or treatment with RA can augment antibody responses in both VA-deficient and VA-adequate animals.”