Determine your optimal daily vitamin C intake based on age, smoking status, health conditions, and stress levels.
Vitamin C (ascorbic acid) is a powerful antioxidant essential for collagen synthesis, immune function, wound healing, and iron absorption. Unlike most animals, humans cannot synthesize vitamin C and must obtain it from diet.
Adults need 75-90mg daily (RDA). Smokers need an extra 35mg. Higher amounts may be beneficial during illness, stress, or recovery from surgery.
The upper limit is 2,000mg/day for adults. Excess is usually excreted in urine, but very high doses can cause digestive upset and kidney stones in susceptible individuals.
Regular supplementation doesn't prevent colds in most people, but it may reduce duration by 8% in adults and 14% in children. Higher doses at illness onset may help.