Condition - Newborns with low vitamin D levels are at increased risk for respiratory infections
Vitamin D is produced by the body in response to sunlight, but achieving adequate levels in winter can be challenging, especially in countries further from the equator. As well as being important for developing and maintaining strong bones, recent evidence suggests that it is also critical for the immune system. During pregnancy and breastfeeding, the infant is entirely dependent on the mother’s supply of vitamin D, so ensuring an adequate level during this critical window is important for an infant’s long-term health.
Results of a study in the January 2011 issue of Paediatrics show that newborn babies’ vitamin D levels predict their risk of respiratory infections. This supports previous studies by the same scientists, which have found that children of women who took vitamin D supplements during pregnancy were less likely to develop wheezing during childhood.
In this new study, the researchers measured the level of vitamin D in samples of umbilical cord blood from more than 922 newborns in New Zealand. The mothers were then asked to complete a questionnaire detailing the incidence of any respiratory problems three and 15 months later, and then annually until the children were five years old.
The results showed that more than 20% of the newborns had very low vitamin D levels (less than 25nmol/L) and more still had vitamin D levels below the optimal range of 75-100nmol/L. What’s more, when the scientists compared the blood test results to the questionnaire data, they found that infants with vitamin D levels below 25nmol/L were twice as likely to have developed respiratory infections as those with levels of 75nmol/L or higher. Lower vitamin D levels were also found to increase the risk of wheezing.
Camargo CA et al. Cord–blood 25–hydroxyvitamin D levels and risk of respiratory infection, wheezing and asthma. Pediatrics 2011; 127(1):e180–7.