- Decreases in retinol and retinol-binding protein during total parenteral nutrition in rats are not due to a vitamin A deficiency. Lespine, A., Periquet, B., Jaconi, S., Alexandre, M.C., Garcia, J., Ghisolfi, J., Thouvenot, J.P., Siegenthaler, G. J. Lipid Res. (1996)