Vitamin C and Respiratory Infections: What the Research Found

Research published in the Journal of Manipulative and Physiologic Therapeutics (1999;22(8):530–533) evaluated whether vitamin C supplementation could help reduce symptoms of respiratory infections in young adults. The study involved 684 students aged 18–32, divided into two groups.

  • Test group (252 students): Received 1,000 mg of vitamin C every hour for the first six hours of illness, followed by 1,000 mg three times daily.

  • Control group (432 students): Received standard over-the-counter treatments such as decongestants and pain relievers.

The results were striking:
Cold and flu symptoms decreased by 85% in the vitamin C group, while no such improvement was seen in the control group.

The study suggests that high-dose vitamin C supplementation may offer meaningful symptom relief during the early stages of a respiratory infection.