Final answer:
Vitamin E is the antioxidant that protects fatty acids from oxidation and is also involved in protecting vitamin A and heme synthesis. It is a fat-soluble vitamin, and its deficiency, though rare, can cause neurological issues.
Step-by-step explanation:
The vitamin that is an antioxidant and protects unsaturated side chains in fatty acids from unwanted oxidation is vitamin E. This vitamin, chemically known as a-tocopherol, is a fat-soluble nutrient that plays a crucial role in protecting cell membranes from oxidative damage by free radicals. Deficiency in vitamin E can lead to neurological problems, although it is rare. It also helps to prevent the oxidation of vitamin A and is involved in heme synthesis. Vitamin C is the water-soluble vitamin that acts as an antioxidant.
Additionally, vitamins like vitamin A and vitamin K are also fat-soluble but serve different functions; vitamin A is crucial for maintaining connective tissue, while vitamin K is essential for blood clotting.