Synopsis

Source of validity: Scientific
Rating (out of 5): 2

Vitamin C (ascorbic acid) has been investigated for its potential benefits in supporting or treating respiratory allergies, such as allergic rhinitis and asthma. The rationale is primarily based on its antioxidant properties and its role in modulating immune responses. Several small clinical studies and observational research suggest that Vitamin C may reduce histamine levels and improve some symptoms of allergic conditions. For example, some trials have demonstrated a reduction in allergy symptoms and histamine concentrations after Vitamin C supplementation, particularly in people with low baseline levels of the vitamin.

However, the overall quality of evidence is limited. Most studies have small sample sizes, variable dosing, and sometimes lack rigorous controls. Systematic reviews generally conclude that while there is a plausible scientific mechanism—given Vitamin C’s role in immune function and as an antioxidant—robust clinical evidence supporting its regular use as a primary or adjunctive treatment for respiratory allergies is weak. Most guidelines for allergy management do not include Vitamin C as a recommended therapy, but some clinicians may suggest it as a supplemental option, especially in individuals with suboptimal Vitamin C status.

In summary, there is some scientific basis for the use of Vitamin C in supporting respiratory allergies, but the evidence is not strong or consistent enough to warrant widespread clinical endorsement. More high-quality, large-scale clinical trials are needed to establish efficacy.

More about Vitamin C (unspecified)
More about Allergies (respiratory)

Other ingredients used for Allergies (respiratory)

Other health conditions supported by Vitamin C (unspecified)

Products containing Vitamin C (unspecified)