Available evidence from this systematic review suggests that high dose vitamin D may prevent  asthma exacerbation .
CONTEXT Observational studies have suggested a relationship between vitamin D status and asthma-related respiratory outcomes .
The benefit of vitamin D supplementation for pulmonary function , symptoms and exacerbations is not well established .
OBJECTIVE To systematic ally review paediatric clinical trials investigating the role of vitamin D on asthma-related respiratory outcomes .
[Plasma 25-hydroxycholecalciferol after daily vitamin D administration in comparison with massive single-dose prophylaxis (author's transl)].
The effect of daily administration of 1200 IU vitamin D3 was compared with the response to a single oral dose of 200,000 IU in 21 young infants by determination of the plasma 25-OHCC levels . After about one week the mean value recorded in group 1 was 27 + /- 13 ng/ml ; the corresponding value in group 2 was 127 + /- 78.4 ng/ml . At the second control examination about one month subsequently , the mean values were 61 + /- 26.2 ng/ml and 104 + /- 69.0 ng/ml respectively . The wide range of values found in the single-dose group clearly demonstrates the advantage of daily vitamin D administration for routine prophylaxis against rickets in infancy
Available evidence from this systematic review suggests that high dose vitamin D may prevent  asthma exacerbation .
CONTEXT Observational studies have suggested a relationship between vitamin D status and asthma-related respiratory outcomes .
The benefit of vitamin D supplementation for pulmonary function , symptoms and exacerbations is not well established .
OBJECTIVE To systematic ally review paediatric clinical trials investigating the role of vitamin D on asthma-related respiratory outcomes .