Dietary Vitamin C Intake Affects Lung Function Through White Blood Cell

Area of Science:

• Nutritional Immunology
• Respiratory Medicine
• Biostatistics

Background:

• Vitamin C, an antioxidant, is increasingly used for pulmonary diseases.
• The precise mechanisms by which vitamin C impacts lung function are not fully understood.
• Potential pathways involve vitamin C's effect on white blood cell (WBC) counts, which can influence lung parenchyma and inflammation.

Purpose of the Study:

• To investigate the relationship between dietary vitamin C intake, WBC counts, and lung function.
• To explore the mediating role of WBCs in the association between vitamin C and lung function.

Main Methods:

• Cross-sectional study utilizing data from 15,738 participants in the National Health and Nutrition Examination Survey (NHANES) 2007-2012.
• Parallel mediation analysis using multivariable logistic regression.
• Mendelian randomization analysis was employed to strengthen the findings.

Main Results:

• Dietary vitamin C intake showed a negative association with WBC counts (p < 0.05, β < 0).
• WBC counts were negatively associated with lung function.
• Dietary vitamin C intake was positively associated with lung function, with a significant positive mediation effect via WBCs (p < 0.05, β > 0).

Conclusions:

• Vitamin C intake may improve lung function by modulating WBC levels.
• WBCs appear to mediate the positive effect of vitamin C on lung function.
• Findings suggest potential mechanisms involving inflammation and proteases, warranting further biochemical investigation.