Possible Interaction: Insulin and Vitamin A

“Subjects younger than 40 years (n = 94) showed a positive association of the frequency of alcohol consumption with the circulating … = 0.344, p = 0.001) and γ-tocopherol levels (β = 0.219, p = 0.041), and an inverse association of fast insulin … serum retinol (β = −0.301, … = 0.009).”

“The insulin level in the 9,000 IU/kg VA group was higher than those in the other groups (P < 0.05).”

“On the other hand, combined treatment with vitamin A and insulin sustained the characteristic of HSC quiescence and completely suppressed the expression of myofibroblastic markers through activation of the JAK2/STAT5 signaling pathway and increased expression of sterol regulatory element binding protein-1.”

“It improved insulin sensitivity and decreased the retinol :RBP4 ratio (P < 0.05).”

“A combination of insulin with vitamin A may provide more benefits than use of either agent alone in the treatment of general characteristics of diabetes and the maintenance of antioxidant defence of diabetic heart and thus in the reduction of peroxidative stress‐induced cardiac injury.”

“Also to evaluate whether a combination of vitamin A and insulin exerts more beneficial effects than treatment with each agent alone.”

“Our findings suggest that the maintenance of ACh-stimulated endothelium-dependent vasorelaxant tone in normal physiological levels depends largely on the prevention and/or inhibition of peroxidative stress, which is achieved by combined treatment with vitamin A plus insulin.”

“The combination of vitamin A plus insulin removed the inhibitory action of H2O2 in diabetic aorta.”

“The use of vitamin A together with insulin provides a better metabolic control and more benefits than use of insulin alone in the reduction of diabetes-induced vascular complications.”

“ Retinol and retinoic acid also … cells growth-stimulated by insulin and other growth factors from the IGF growth factor family (des(1-3)IGF-I and IGF-II), as well … factors from the epidermal growth factor family (EGF and TGF-α), with retinoic acid being more effective than retinol.”

“The growth-stimulating effect of insulin , EGF and TGF-α was inhibited 42–64% by retinol and retinoic acid at 100 ng/ml, and 64–84% at 10000 ng/ml.”

“ All-trans-RA at 10-6 M decreased the [3H]-thymidine labelling index of mesenchyme of BUGs cultured in medium with DHT plus insulin or DHT alone, but did not decrease the [3H]-thymidine labelling index of epithelium.”

“ Insulin and retinol alone had no significant effect on inhibin secretion; however, together they appeared to enhance the ability of FSH to stimulate inhibin secretion.”

“It was found that the secretion of transferrin was regulated by the interaction of insulin with FSH, testosterone and retinol.”