What happens to your body when you start taking vitamin C?

Unlocking the Benefits: What Happens When You Start Taking Vitamin C

Vitamin C (ascorbic acid) is an essential, water-soluble nutrient involved in many biochemical processes. Because humans cannot synthesize it, dietary intake or supplementation is necessary to maintain adequate levels. When you begin taking vitamin C regularly, measurable changes can occur across immune function, antioxidant protection, connective tissue synthesis, iron metabolism, and skin health.

Immune function and infection response

Vitamin C accumulates in white blood cells and supports innate and adaptive immunity. It aids neutrophil migration, enhances phagocytosis, and helps resolve inflammation by promoting apoptosis of spent immune cells. Randomized and observational studies suggest vitamin C can modestly reduce the duration and severity of upper respiratory infections in certain populations, particularly under physical stress. For a focused review of practical effects, see this overview on what happens to your body when you start taking vitamin C.

Antioxidant protection and oxidative stress

As a potent antioxidant, vitamin C donates electrons to neutralize reactive oxygen species and helps regenerate other antioxidants such as vitamin E. Regular intake lowers biomarkers of lipid peroxidation in high-risk groups (for example, smokers or those exposed to pollution) and can attenuate exercise-induced oxidative stress in athletes, supporting recovery and reducing cellular damage.

Collagen synthesis and tissue repair

Vitamin C is a required cofactor for prolyl and lysyl hydroxylases—enzymes essential for stabilizing collagen. Adequate intake improves wound healing, supports vascular integrity, and contributes to bone and joint matrix maintenance. Clinically, pronounced deficiency causes scurvy, but even suboptimal intakes impair tissue repair and skin resilience.

Skin health and appearance

Oral vitamin C supports dermal collagen production, limits UV-induced oxidative damage, and can reduce hyperpigmentation by influencing melanin synthesis. These effects complement topical antioxidant strategies and help maintain hydration and skin elasticity over time.

Iron absorption and systemic effects

Vitamin C increases non-heme iron absorption by reducing ferric (Fe3+) to ferrous (Fe2+) iron in the gut, which can be especially useful for people on plant-based diets or those with marginal iron status. Consistent intake therefore supports hematologic health alongside direct roles in immune and connective tissue function.

Practical dosing and safety

Maintenance intakes in research contexts often range from 200–1,000 mg daily to support antioxidant and immune roles; the tolerable upper intake is commonly placed at 2,000 mg/day due to gastrointestinal tolerance considerations. Individuals under chronic stress, older adults, or smokers may require higher intakes to achieve comparable plasma levels. Balance with a varied diet remains important.