A Randomized Trial of Vitamin D to Reduce Respiratory Infection

Effect of Vitamin D3 Supplementation to Reduce Respiratory Infections in Children and Adolescents in Vietnam: A Blinded, Placebo-controlled Randomized Controlled Trial

The goal of this study is to assess the effectiveness of vitamin D in reducing laboratory-confirmed influenza and in reducing non-influenza viral respiratory tract infections. A cohort of children between the ages of 3 and 17 years from the Thanh Ha Commune, Thanh Liem District, Ha Nam Province, Vietnam will be randomized to either weekly vitamin D supplements or placebo. Participants who develop acute respiratory infection over a 12-month period, will be tested for influenza, the co-primary outcome, and other respiratory viruses, the other co-primary outcome, by RT-PCR.

Inclusion Criteria:

• Between the ages of 3 and 17
• Residing in Thanh Liem District, Ha Nam Province, Vietnam

Exclusion Criteria:

• Born prematurely at less than 32 weeks gestation
• Any chronic illness (except asthma)
• Currently using medication known to interfere with vitamin D metabolism
• Children with a sibling participating in the study