Vitamin D and respiratory infections in infants and toddlers: a nutri-shine perspective

Abstract

There is compelling evidence of a global problem of poor vitamin D status in expecting mothers and postnatal life; and even more critical, is the evidence showing the association of vitamin D deficiency with increased morbidity and mortality risks from respiratory infections. Viral and bacterial pneumonia kills more children than any other illness, accounting for 19 % of all deaths in children less than five years of age worldwide; and under-nutrition, which includes vitamin D insufficiency/deficiency, has been implicated in 53 % of all these deaths. Poor vitamin D status is a result of insufficient sunlight exposure and/or poor dietary intake. Greater understanding of the role of vitamin D deficiency in precipitating lung infections grew from the use of rodent models and observational and intervention studies in infants and toddlers. Vitamin D adequacy is important to maintaining the key protective mechanism of developing lungs since it mediates the synthesis of antimicrobial peptides, the lungs strongest defense against viral and bacterial pathogens. If vitamin D intervention currently under study in several clinical trials is proven successful, then implementation of new fortification practices, revised guidelines for healthy sun exposure and public health programs for vitamin D supplementation of pregnant/lactating women and their infants may be effective strategies to aide in preventing neonates and children under five from developing pneumonia. Globally, there is potential to save more than a million young lives with preventive treatment, a compelling reason why the efficacy of optimizing vitamin D mediated defense against respiratory pathogens in infants and children merits further study.