Vitamins to Breathe

Exercise induced bronchoconstriction could be reduced with vitamin C intake before exercise

/ Author:  / Reviewed by: Dominique Brooks, M.D

(RxWiki News) It's good to huff and puff after a hard work out. But too much wheezing and coughing could be a sign of a more serious breathing condition. Vitamin C could help with that.

Taking vitamin C before exercise helped reduce breathing constrictions during the activity, a new review found.

According to these researchers, the findings revealed that physically active people can take vitamin C if they cough, wheeze or have other breathing issues while exercising.

"Talk to your MD about vitamin C before exercise."

Harri Hemilä, PhD, from the Department of Public Health at the University of Helsinki in Finland, looked at how vitamin C affected exercise-induced bronchoconstriction (EIB), which occurs when the airway narrows during exercise.

With EIB, chest tightness, coughing and wheezing can occur with exercise. Previous research has shown that vitamin C can play a role in lung function, according to Dr. Hemilä.

Dr. Hemilä gathered three previously published studies regarding EIB and vitamin C. The studies included 40 children and adults of all ages and genders.

Dr. Hemilä tracked participants' forced expiratory volume (FEV1), or the maximum amount of air that can be expelled from the lungs for one second, after exercising.

Participants' lung volume was measured after exercising to compare the effects of vitamin C intake against a placebo, or fake medicine. The participants and the researchers from the previous studies did not know whether they were receiving vitamin C or the placebo.

Within the previous studies, at least 0.2 grams of vitamin C were given orally or as a shot. Doses were given on a single day or for an extended period of time.

Dr. Hemilä paid particular attention to the trials that included larger doses of vitamin C. He also tracked the number of participants who had exercise-induced bronchoconstriction after exercising.

After comparing the studies, Dr. Hemilä found that when vitamin C was given before exercise, the amount that the forced expiratory volume decreased after exercise went down by 48 percent afterwards.

Vitamin C influences the growth of prostanoids, which affect inflammation in the lungs, according to Dr. Hemilä. The vitamin can also work as an antioxidant to combat the free radicals caused by exercise that can lead to cell damage.

One of the studies also reported that vitamin C lowered the proportion of participants who had breathing issues with exercise-induced bronchoconstriction by 50 percent.

"Given the low cost and safety of vitamin C and the consistency of positive findings in the three studies on EIB, it seems reasonable for physically fit and active people to test vitamin C on an individual basis if they have respiratory symptoms such as cough associated with exercise," Dr. Hemilä wrote in his report.

The author noted that although the included studies had a small number of participants overall, the studies were performed in three different decades on two different continents.

Future research should continue to look into vitamin C and how effectively it reduces respiratory symptoms in physically active individuals, according to Dr. Hemilä.

The study was published online June 7 in the journal BMJ Open. No conflicts of interest were declared and no outside funding was received.

Reviewed by: 
Review Date: 
June 14, 2013
Last Updated:
August 6, 2013