NAF Vitamin E and Selenium PlusNAF Vitamin E & Selenium Plus is particularly useful in those geographical areas where the soil is likely to be selenium deficient. Contains selenium yeast, safer to use than inorganic forms. Vitamin E is a powerful antioxidant that has the ability to stabilise cell membranes, thus helping to protect the cell from the detrimental effects of excess free radicals. Studies have also indicated the beneficial effects this vitamin can have on the horses