Infants' vitamin D lack ups infection risk

BOSTON, Dec. 27 (UPI) -- U.S. researchers have linked low vitamin D levels in newborns to higher respiratory infection risks by the age of 3 months.

Researchers at Massachusetts General Hospital in Boston also associated low vitamin D levels and higher risk of wheezing during early childhood but not with higher risks of developing asthma.

"Our data suggest that the association between vitamin D and wheezing, which can be a symptom of many respiratory diseases and not just asthma, is largely due to respiratory infections," study leader Dr. Carlos Camargo said in a statement. "Acute respiratory infections are a major health problem in children. For example, bronchiolitis -- a viral illness that affects small airway passages in the lungs -- is the leading cause of hospitalization in U.S. infants."

The study, scheduled to be published in January's Pediatrics, indicates infants with levels of vitamin D below 25 nanomoles per liter were twice as likely as those with levels 75 nmol/L or higher to develop respiratory infections by 3 months.

Camargo and colleagues looked at children tracked up to age 5 in the New Zealand Asthma and Allergy Cohort Study. Midwives or study nurses gathered a range of measures -- including 922 samples of umbilical cord blood tested for 25-hydroxyvitamin D.