MedicalResearch.com Interview with:
Hans Bisgaard, MD, DMSc
Professor of Pediatrics
The Faculty of Health Sciences
University of Copenhagen
Head of the Copenhagen Prospective Studies on Asthma in Childhood
University of Copenhagen and Naestved Hospital
MedicalResearch: What is the background for this study? What are the main findings?
Dr. Bisgaard: Vitamin D deficiency has become a common health problem in westernized societies, possibly caused by a more sedentary indoor lifestyle and decreased intake of vitamin D containing foods. Vitamin D possesses a range of immune regulatory properties, and it has been speculated that vitamin D deficiency during pregnancy may affect fetal immune programming and contribute to asthma pathogenesis. Asthma often begins in early childhood and is the most common chronic childhood disorder. Observational studies have suggested that increased dietary vitamin D intake during pregnancy may protect against wheezing in the offspring, but the preventive effect of vitamin D supplementation to pregnant women is unknown. In our double-blind, single-center, randomized clinical trial conducted within the Copenhagen Prospective Studies on Asthma in Childhood 2010 cohort we supplemented 2800 IU/d of vitamin D3 during the third trimester of pregnancy compared with 400 IU/d in the control group. Although the maternal supplementation did not result in a statistically significant reduction of risk of persistent wheeze in the offspring through age 3 years, the interpretation of the study is limited by a wide confidence interval that includes a clinically important protective effect.