Nearly forgot to mention the new study of Jenni Rosendahl who compared high-dose to low-dose vitamin D supplementation effects. The Vitamin D Intervention in Infants (VIDI) study was a randomized controlled 24-month trial of daily 400 IU or 1200IU vitamin D supplementation administered to healthy infants that evaluated the effect of vitamin D supplementation on bone health and infections.
Comparing the first line in table 1 and table 2, I would say sensitization against one of the most common allergen in this age group happens already in the low dose group while the higher dose leads to a 2.2fold increased disease risk.
Would be really important to have any unexposed control group. At least from RCT No1, the risk could be much higher.