Relation between serum vitamin D level and asthma

Asthma is a chronic multifactorial condition racterized by inflammation, bronchial hyperresponsiveness, narrowing of airway associated with wheezing and shortness of breath, where trials have evidenced that approximately 50% despite being on adequate treatment don't achieve optimal control. Asthma has been related to vitamin D deficiency, where lower levels have been correlated to an increased hyperreactiveness and lower measures in pulmonary function test. Up to our knowledge, no studies have been conducted in Hispanic patients for this association.

Cross-Sectional pilot study in the setting of a pneumology office practice. Population consisted of asthmatic patients with no past medical history or risk factors for lower vitamin D levels. Variables studied included Peak-Flow s a measurement of the maximal velocity of air expelled in a forced exhalation adjusted for height and age; Serum vitamin D levels where optimal was > 30, and deficient < 30. Data coIlection period occurred between January 2010 and May 2011.

A direct proportion relation between vitamin D levels and asthma control test (ACT) questionnaire was noted. An inversely direct proportion between vitamin D and peak flow was evidenced, while no relation noted between peak flow and asthma.

An 80% prevalence of vitamin D deficiency was noted in our population. Higher levels of vitamin D were associated with higher punctuation on ACT questionnaire, evidencing that most patients felt better during the last month. Peak flow measurements resulted to be lower when vitamin D was higher, though this measure could be influenced by a variety of external conditions.