Special K contains 2% or less of sugar, salt, malt flavouring, sucralose, natural and artificial flavour, and BHT for freshness. Vitamins and minerals include vitamin C (ascorbic acid), vitamin E (alpha tocopherol acetate), niacinamide, reduced iron, vitamin B (pyridoxine hydrochloride), vitamin B (thiamin hydrochloride), vitamin A (palmitate), vitamin B (riboflavin), folic acid, and vitamin B In the US, Special K provides meal replacements in two different forms, protein meal bars and protein shakes. There are eleven varieties of Special K Protein Meal Bars: Mocha Crunch Protein, Chocolate Peanut Butter, Strawberry, Double Chocolate, Chocolatey Chip, Honey Almond, Cranberry Walnut, Chocolate Caramel, Chocolatey Brownie,
L-gulonolactone oxidase deficiency living in a malarial infested environment". He based his observation on evidence which indicates that G6PD deficient individuals display enhanced sensitivity to ascorbic acid induced hemolysis. Studies of human diseases have benefited from the availability of small laboratory animal models. However, the tissues of animal models with a GULO gene generally have high levels of ascorbic acid and so are often only slightly influenced by exogenous vitamin C. Guinea pigs, for instance, are a popular human model but lost the ability to synthesize L-gulono-gamma-lactone oxidase 20 million years ago. This is a major handicap for studies involving the endogenous