Asthma Sufferers: More Vitamin C = Less Medication

Newswire (January 12, 2006)—People with asthma may require less inhaled medication if they also take vitamin C, according to the journal Respiratory Medicine (2006;100:174–9). Inhaled corticosteroids are the most commonly prescribed medications for asthma, but long-term use is associated with a number of undesirable side effects, such as cataracts, bone loss, and immune-system suppression. The results of the new study suggest that vitamin C supplementation may be a way to reduce the amount of steroid drugs needed to keep asthma symptoms under control.

In this two-part study, British researchers first determined whether vitamin C (1 gram per day for 16 weeks) or magnesium (450 mg per day for 16 weeks) could control asthma symptoms better than placebo in 92 adults with asthma. In a study like this, benefits of supplements are likely to be small and difficult to detect because the vast majority of people with asthma already control their symptoms using drugs. Thus, there was little opportunity for people in this study to improve as long as they remained on the drugs, which they did throughout the study.

Vitamin C and magnesium failed to improve symptom control significantly over baseline levels. But as previous research has suggested that these nutrients could offer a benefit, the authors designed a second part to the study to discover whether any beneficial effects of the supplements might have been masked by the drugs. To explore this, the people continued their supplement (vitamin C, magnesium, or placebo) while undergoing a ten-week, staged reduction in their corticosteroid medication.
Vitamin C was found to have a modest sparing effect: people who took vitamin C were able to reduce their intake of inhaled corticosteroids without any loss of symptom control. This is important because the side effects of corticosteroid drugs increase when higher doses are used; reducing daily intake, even by a small amount, could prevent some adverse effects. Magnesium was not found to be effective.

The adrenal glands are responsible for producing the body’s own corticosteroid hormones. Research suggests that the adrenals require vitamin C to make these hormones. Thus it makes sense that taking a vitamin C supplement could support the body’s own production of adrenal corticosteroids, possibly reducing the amount of hormone needed in drug form.

People taking asthma medications should never abruptly discontinue their steroid medications, even if they are taking vitamin C. Too rapid withdrawal from steroid medications can cause serious health problems. Always work with the prescribing doctor to adjust the amount of any prescription medication.