Si tacuisses

The BAMSE study group published another vitamin paper – mainly on current multivitamin use and allergy.

Our results …. suggest that supplementation with multivitamins during the first years of life may reduce the risk of allergic disease at school age.

Any further conclusion on early exposure of vitamin D, however, is probably impossible for 3 simple reasons:

1. The project started with 4,093 children; at age 8 only 2,423 children are included while even less (2,069) filled in the FFQ question of current intake – that’s not representative for the whole cohort and a poor exposure variable too.

2. The study doesn’t care about seasonal effects – although relevant for reporting allergic symptoms as well as having varying vitamin D levels during the course of a year. There are no validation data for the FFQ – how good is it for the study question and why are there no dose estimates? There are no crude OR’s at all (table 4); what has been the effect of adjusting for various confounders? Maybe the logistic models should not be adjusted for breastfeeding as this might be a causal factor…

3. Vitamin D effects cannot be examined in this study at all. The discussion clearly shows that all babies are exposed to vitamin D

It should be noted, though, that 98% of the children in our study received supplementation of vitamins A and D from 2 wk of age and through the first years of life.

with other vitamin D studies are not even mentioned in the discussion (not even the first large study in the field) this paper is only about current multivitamin effects. The earlier work was more straight on early vitamin D effects – maybe an update of cohort effects would have been more exciting than a largely no-effect new cross-sectional analysis, yea, yea.