Vitamin D levels at birth and risk of type 1 diabetes in childhood: a case–control study

Aims To assess whether vitamin D levels at birth were associated with risk of having type 1 diabetes up to 10 years of age and the potential modifier effect of ethnic group. Methods The Piedmont Diabetes Registry and the Newborn Screening Regional data were linked to identify cases ( n = 67 incident children aged ≤10 years at diabetes onset, 2002–2012) and up to five controls ( n = 236) matched for birthday and ethnic group. Cards with neonatal blood spot were used and 25-hydroxyvitamin D(3) assessed with tandem mass spectroscopy. Results In conditional logistic regression, OR for unit increment of log vitamin D was 0.78 (95 % CI 0.56–1.10). Vitamin D was significantly lower in migrant than in Italian control newborn babies ( p