Higher neonatal vitamin D levels tied to lower risk of childhood asthma

  • Thorsteinsdottir F & al.
  • Nutrients
  • 21 Mar 2020

  • curated by Sarfaroj Khan
  • UK Clinical Digest
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Takeaway

  • Higher neonatal 25-hydroxyvitamin D3 (25[OH]D3) concentrations may lower the risk of developing childhood asthma at ages 3-9 years.

Why this matters

  • Findings suggest that prenatal vitamin D concentrations are important for the development of foetal lung and immune system and reduce the risk of asthma later in life.

Study design

  • A case-cohort study included 911 children with asthma (cases) and 1423 children from random sub-cohort using data from the Danish biobank and register databases.
  • The effects of neonatal vitamin D status on the development of asthma between age 3-9 years were evaluated across different quantiles (Q1-Q5).
  • Funding: This study was a part of the D-Tect study funded by the Danish Agency for Science, Technology and Innovation, the Ministry of Science, Higher Education, under the instrument “Strategic Research Projects”.

Key results

  • The median 25(OH)D3 concentration was slightly lower in children with asthma (23 [interquartile range (IQR), 14-35] nmol/L) vs children from the sub-cohort (25 [IQR, 14-40] nmol/L).
  • After adjustment for confounders, the risk of developing asthma between age 3-9 years was lower for children in the fifth quintile vs with those in the first quintile (aHR, 0.55; 95% CI, 0.39-0.77).
  • In analyses stratified by sex and season of birth, the association appeared stronger in boys (aHR, 0.53; 95% CI, 0.34-0.83) than girls (aHR, 0.62; 95% CI, 0.36-1.07); and in those born in August-January (HR, 0.51; 95% CI, 0.33-0.79) than those born in February–July (HR, 0.66; 95% CI, 0.43-0.99).

Limitations

  • Risk of residual confounding.