NANP Board Practice Exam 2025 - Free NANP Board Practice Questions and Study Guide

The correct choice highlights a group of nutrients that serve as redox agents, which are essential in combating oxidative stress caused by free radicals in the body. Vitamins C and E, along with glutathione, lipoic acid, and cysteine, are known for their antioxidant properties.

Vitamin C is a potent water-soluble antioxidant that can directly neutralize free radicals and regenerate other antioxidants. Vitamin E, a fat-soluble antioxidant, plays a crucial role in protecting cell membranes from oxidation. Glutathione, often referred to as the body's master antioxidant, helps in detoxifying harmful substances and regenerates other antioxidants. Lipoic acid can function in both aqueous and lipid environments, further aiding in antioxidant defense and regeneration of other antioxidants, while cysteine is a precursor to glutathione and also has antioxidant properties.

The other options contain nutrients that may support overall health but do not have the same direct role in oxidative stress reduction as the nutrients listed in the correct answer. Vitamins D, calcium, and potassium focus more on bone health and electrolyte balance rather than direct antioxidant activity. Iron, folic acid, and selenium are vital for numerous bodily functions but do not primarily act as antioxidant agents in the same way. Niacin, riboflav