A new abstract at the recent ATS congress now clears the 2007 controversy between the Camargo and Gale studies on the effect of vitamin D: Wheezing is not asthma (as the atopy component is missing?).
[… ] Frozen cord blood from 922 infants in the NZ Asthma and Allergy Cohort Study was tested for 25(OH)D. Parents were asked if their child had a history of respiratory infection at age 3m, or history of wheezing at age 15m and then annually thereafter. Current asthma was defined as doctor-diagnosis of asthma by age 5y, plus reported wheeze or inhaler use since age 4y […] After adjustment for season of birth, cord blood 25(OH)D levels were inversely associated with wheeze by age 15m, 3y, and 5y (all p<0.05). The adjusted odds ratio (95%CI) for wheeze by age 5y increased across categories of cord blood 25(OH)D (75+, 25-74, and <25 nmol/L): 1.0 (ref), 1.6 (1.1-2.3), and 2.2 (1.3-3.5). Odds of respiratory infection by age 3m showed a similar pattern: 1.0 (ref), 1.4 (1.0-2.0), and 2.2 (1.3-3.4). [...] By contrast, cord blood 25(OH)D had no association with current asthma at age 5y: 1.0 (ref), 1.2 (0.8-1.8), and 0.9 (0.5-1.6).
In case you still do not believe in suppressive effect of vitamin D, here is an older abstract: