Vitamin A, zinc and lung cancer

Serum vitamin A concentration were measured in 26 newly diagnosed lung-cancer patients and found to be significantly lower than those of patients of similar age with either non-malignant lung or non-lung diseases. The levels of vitamin A in the lung-cancer patients, but not in the controls, were significantly correlated with serum concentrations of retinol-binding protein (RBP) and zinc. It is suggested that low levels of zinc might reduce the synthesis of RBP and thus reduce the mobilization of vitamin A from the liver.