So the major antioxidants (in terms of nutrients) are vitamins A, C, E, selenium, and zinc. There are other nutrients that exhibit antioxidant properties, but these are considered the core antioxidant nutrients.
Vitamin A: also known as Retinol, vitamin A is important for maintaining healthy vision, bone growth and development, as well as maintaining epithelial tissue. Its primary roles include cell proliferation and cell division, along with vision. Its benefits come from carotenoids found in food, and are converted into retinol in the liver. Additionally, it is a powerful antioxidant and possesses anti-tumor qualities. It helps maintain the shape of mucus membranes, allowing things that are only supposed to pass. Vitamin A is also crucial for the development of quality enamel on teeth. Vitamin A is important for steroid synthesis (along with cholesterol) and cell differentiation, which is needed for healthy growth and development of all tissue types. Carotene, or Provitamin A, is a major antioxidant, and is found in all warm-colored vegetables (red, orange, and yellow). Good sources of vitamin A are animal liver, carrots, sweet potatoes, butter, kale, spinach, and broccoli. Deficiencies can lead to vision problems, including blindness, as well as respiratory infections and decreased overall immune system function. Some antibiotics, cholesterol-lowering drugs, and laxatives interfere with the absorption of vitamin A.
Vitamin C: also known as ascorbic acid, vitamin C plays an essential role in both tissue growth/repair and collagen synthesis. Additionally, it is also a powerful antioxidant, and works in conjunction with vitamin E. It is involved in maintaining the integrity of blood vessel walls and adrenal gland function. Vitamin C is involved in the synthesis of steroid hormones. Vitamin C is a regulator of immune function by increasing macrophage (a type of white blood cell) activity. In as early as the beginning of the 21st century, megadoses (10-30g+/day) of ascorbic acid was shown to help treat the common cold, along with other ailments. Unfortunately, these studies have not been replicated at a high enough dosage to see results, as these studies normally cap out at 1g/day as a treatment method. More research would be needed to substantiate these results. Deficiency in ascorbic acid can lead to scurvy, fatigue, weakness, shortness of breath, muscle cramps, and achy joints. Vitamin C is found in high amounts in citrus fruits, watermelon, red chili peppers, tomato juice, sweet potatoes, cauliflower, brussels sprouts, and broccoli.
Vitamin E: This vitamin’s main function is the removal of harmful free radicals. Vitamin E is important in the protection cell membranes and plasma lipoproteins specifically. Vitamin E is not one particular substance, but rather a family of eight different compounds, depending on the positions of certain atoms within its structure. Vitamin E is needed for proper circulation to muscle and nerve tissues, as well as is involved in healing processes in the body. Additionally, vitamin E is known to have both powerful anti-inflammatory and anti-platelet aggregating (blood clotting) properties. This makes it useful for those who form blood clots too often. Research suggests vitamin E works with selenium and zinc to help prevent both cardiovascular disease and even some forms cancer. Vitamin E can be found in nuts, seeds, legumes, butter, seaweed, and green leafy vegetables.
Selenium: along with vitamin E, selenium’s major role is as an antioxidant. Selenium is involved in immune function, as it helps eliminate free radicals in the body. It is also important in maintaining healthy heart function, pancreatic function, and connective tissue (like skin and muscle) elasticity. Deficiency in selenium has been associated with Duchenne’s muscular dystrophy, Keshan’s disease, and Kashin-Beck disease. Selenium can be found in Brazil nuts, butter, seafood, and grains grown in selenium-rich soil.
Zinc: Zinc is needed for proper mental development and maintenance of healthy reproductive organs, especially the prostate gland. Zinc is also involved in collagen formation and the synthesis of cholesterol, proteins, and fats. Zinc regulates the release of vitamin A from the liver, and is important for maintaining vision. In fact, night blindness can be a symptom of low zinc intake. Blood sugar regulation requires adequate amounts of zinc as well. Symptoms of low zinc levels are delayed sexual development, growth retardation, loss of taste or smell, delayed wound healing, and loss of appetite. Low zinc consumption during pregnancy can lead to birth defects. Zinc absorption is inhibited by increased intake of iron and copper. Zinc can be found in oysters, red meat, seeds, ginger, fish, nuts, kidney beans, and turkey.
Hope this helps!