Vitamin D supplementation for treatment and prevention of pneumonia in under-5 children: a randomizeddouble-blind placebo-controlled trial.  Gupta et al., 2016[165]  India  324 children with severe pneumonia  Single dose 100,000 IU  No significant difference in duration of hospitalization, complete resolution of symptoms and risk of recurrent pneumonia; slightly quicker resolution of severe respiratory distress (1 h).