Can vitamin C help treat respiratory congestion?

Respiratory congestion is often caused by allergens. These may be food allergens, allergens in the air, such as pollen, mold, dust mites, animal dander, or household cleaning products that release chemical allergens. When your body is exposed to allergens, it releases proteins called histamines, which attach themselves to the cells in your body and cause the cells to become swollen and leaky. High histamine levels are associated with respiratory congestion, especially in the nasal passages and the sinuses.

Vitamin C is a natural antihistamine and studies have found that taking daily supplements of vitamin C helps to reduce histamine levels and congestion. In one study, the subjects were given 1,000 mg of vitamin C supplements three times a day. The study results showed that histamine levels were reduced in people who had high histamine levels. However, the effects of vitamin C on people with congestion as a result of acute sinusitis, which is usually caused by a cold or flu, are unclear and further study is necessary. Preliminary studies have shown positive outcomes when injecting vitamin C into the sinuses of people with acute sinusitis.


Vitamin C can be found naturally in many fresh fruits and vegetables, such as strawberries, oranges, lemons, broccoli, tomatoes, blueberries and artichokes. If you are suffering from respiratory congestion, try taking a 1,000 mg vitamin C three times a day and you should find yourself feeling less congested. It is important to be careful when taking vitamin C supplements because large amounts of vitamin C may cause an upset stomach and diarrhea. If you experience these symptoms, reduce the amount of vitamin C you are taking. If you would like to try other natural remedies for respiratory congestion, try using mint, eucalyptus oil, menthol, tea tree oil, echinacea or oregano.