Background: Occupational asthma occurs in a significant number of adult unset forms of
asthma. Even after exposure cessation, persistent asthma is frequent. Although recognized as important,
nutrition, specifically vitamin D intake, was rarely evaluated in occupational asthma.
Objective: To assess the vitamin D intake in occupational asthma patients and the relation with body
mass index, co-morbidities related to vitamin D deficit, lung function and quality of life.
Results: We found a reduced vitamin D intake in both irritant and allergic asthma, in obese and nonobese
patients. The average intake in non-obese patients, although higher, did not reach statistical significance.
We also found lower vitamin D intake in the mild asthma group versus the severe group,
marginally reaching the significance level (p=0.056) at the median test. Regression analysis in asthma
subpopulations revealed a different pattern of correlation, with a stronger relationship between the
BMI and the impact score in irritant asthma and a closer link between vitamin D intake and symptoms
score (p= 0.027) in the allergic asthma group.
Conclusion: The relation between obesity and vitamin D on clinical scores and lung function seems to
be different according to the asthma phenotype. However, our study supports the usefulness of nutritional
interventions in all occupational asthma patients, targeting both the reduction of the fat mass and
the achievement of the recommended daily intake of vitamin D. When analyzing the impact of the
weight loss effect on asthma evolution, the vitamin D status should also be considered as an influencer.