Bottom Line: Black infants born preterm who received sustained vitamin D supplementation had a lower likelihood of recurrent wheezing by age 1.
Why The Research Is Interesting: Wheezing is a common complication of preterm birth and black infants have higher rates of prematurity-associated wheezing. This randomized clinical trial assessed two vitamin D supplementation strategies in preventing recurrent wheezing.
Who and When: 300 black infants born at 28 to 36 weeks between January 2013 and January 2016.
What (Study Interventions and Measures): 400 IU/day of vitamin D until 6 months of age adjusted for prematurity or a diet-limited approach (stopping supplementation once a baby was receiving at least 200 IU/day of vitamin D from formula or a fortifier added to human milk) (interventions); recurrent wheezing by age 1 (outcome).
How (Study Design): This was a randomized clinical trial (RCT). RCTs allow for the strongest inferences to be made about the true effect of an intervention. However, not all RCT results can be replicated in real-world settings because patient characteristics or other variables may differ from those studied in the RCT.
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Authors: Anna Maria Hibbs, M.D., M.S.C.E., Case Western Reserve University School of Medicine, Cleveland, and coauthors
Results:
Experienced recurrent wheezing by age 1: 31.1% of infants in the sustained supplementation group; 41.8% of infants in the diet-limited group.
Study Limitations: There was the potential for misclassification of wheezing by the study's questionnaire.
Study Conclusions: Among black infants born preterm, sustained supplementation with vitamin D, compared with diet-limited supplementation, resulted in a reduced risk of recurrent wheezing by 12 months' adjusted age. Future research is needed to better understand the mechanisms and longer-term effects of vitamin D supplementation on wheezing in children born preterm.
For more details and to read the full study, please visit the For The Media website.
(doi:10.1001/jama.2018.5729)
Editor's Note: Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.
JAMA