Vitamin C's Antioxidant Effects and COPD Prognosis

Participants in this arm will receive 400 mg of Vitamin C, administered as two 100 mg tablets in the morning and two 100 mg tablets in the evening, for a total of 12 months. The intervention aims to support antioxidant defense and improve clinical outcomes in COPD patients.

Participants in this group will receive a placebo, identical in appearance to the active nutrient supplement (Vitamin C) tablets, with no active ingredients. The placebo will be administered as two tablets in the morning and two tablets in the evening (four tablets per day) for a duration of 12 months, serving as a control to compare the effects of the active intervention.