A new abstract shows
Perinatal data for singleton children who were prescribed anti-asthmatic medication (n = 61 256) were compared with corresponding data for all singleton children born in Sweden … (n = 1 338 319). … Being the first-born child, maternal age above 44 yr, involuntary childlessness for more than 1 yr, maternal smoking during pregnancy, maternal diabetes mellitus of any kind, pre-eclampsia, caesarean section, and instrumental vaginal delivery were all associated with an increased prescription of anti-asthmatic medication during childhood. Preterm birth, low birth weight, being small for gestational age, respiratory problems, mechanical ventilation, and sepsis and/or pneumonia were also associated with increased drug prescriptions. Neonatal phototherapy and/or icterus were risk determinants for children who developed asthma before the age of 12. After controlling for confounders, the odds ratio for phototherapy and/or icterus remained at 1.30 (95% confidence interval 1.16-1.47).
Asthma is a iatrogenic disease – all factors are proxies of increases doctor’s contact. IMHO the question is – Is it vitamin D, paracetamol, antibiotics or anything else how we treat newborns?
AFAIK phototherapy is not related to vitamin D levels (as the “bili light” does not contain the UVA / UVB spectrum), however, most medics will believe that supplementing vitamin D of newborns is useful.