I would recommend that you get your selenium from natural sources such as cereals (eg. corn, wheat, and rice), nuts (brazil nuts and walnuts), legumes (soybeans), animal products (beef, chicken, egg, cheese), seafood (tuna). Other selenium rich foods are oats, cods and turkey. Brazil nuts are among the very rich sources of selenium, so be careful because the selenium intake may reach to toxic level.
But you can carry on with your Cod liver oil because it contains the fatty acids that are good for skin and hair as they are the constituents of the cells' membranes.
Vitamins A and E can eb toxic in excess because they are fat-soluble,so only one supplement is enough for you.