Vitamin A deficiency and serum or plasma fibronectin in the rat and in human subjects.

Fibronectin, a high-molecular-weight glycoprotein occurring in plasma and on the surface of many cells, is involved in cell adhesion and other cell-surface phenomena. Vitamin A deficiency in rats resulted in a threefold increase in the concentration of fibronectin in serum, as measured immunochemically. In vitamin A-depleted human subjects, on the other hand, no correlation could be found between plasma retinol and fibronectin levels.