Antioxidant Vitamins

These vitamins prevent oxidative damage by neutralizing reactive oxygen species (ROS) and free radicals.

Main antioxidant vitamins:

• Vitamin E (α-tocopherol) – Lipid-soluble, protects cell membranes from lipid peroxidation.
  Normal plasma level: 5–20 μg/mL

• Vitamin C (ascorbic acid) – Water-soluble, regenerates vitamin E and scavenges ROS in cytosol.
  RDA: 75–90 mg/day

• Vitamin A (retinol, β-carotene) – Quenches singlet oxygen, protects membranes, enhances immune function.
  Toxicity if >10,000 IU/day chronically

Example reaction:
O₂⁻ + Vitamin C → H₂O₂ (detoxified further by catalase/glutathione peroxidase)