MGH Logo Vitamin D seems to be extremely crucial in the health terrain and those lacking it can face threat for a number of ailments. A latest study suggests that newborns with low vitamin D levels have an increased risk of respiratory infections during infancy and wheezing in early childhood. It was mentioned vitamin D levels may not interfere with the chances of being diagnosed with asthma.

Apart from developing and maintaining strong bones, vitamin D also appears to play an important role in the immune system. At the time of the study, it was observed that children of women who took vitamin D supplements during pregnancy were less likely to develop wheezing during childhood. The current investigation focused on highlighting the probable relation between the actual vitamin D blood levels of newborns and the risk for respiratory infection, wheezing as well as asthma. Investigators thoroughly scrutinized data from the New Zealand Asthma and Allergy Cohort Study that included more than 1,000 children.

Carlos Camargo, MD, DrPH, of the Massachusetts General Hospital (MGH), who led the study, affirmed, “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. 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.”

Midwives or study nurses provided samples of umbilical cord blood, from newborns whose mothers enrolled them in the study. On the other hand, mothers were made to fill in questionnaires that asked about respiratory and other infectious diseases, the incidence of wheezing, and any diagnosis of asthma. The questionnaires were completed after 3 and 15 months as well as every year till the kid aged 5 years. Experts evaluated cord blood samples for levels of 25-hydroxyvitamin D (25OHD), that possibly is the best measure of vitamin D status. While 922 newborns provided cord blood samples, more than 20 percent of them supposedly had 25OHD levels less than 25 nmol/L, which is considered very low.

Camargo, quoted, “There’s a likely difference here between what causes asthma and what causes existing asthma to get worse. Since respiratory infections are the most common cause of asthma exacerbations, vitamin D supplements may help to prevent those events, particularly during the fall and winter when vitamin D levels decline and exacerbations are more common. That idea needs to be tested in a randomized clinical trial, which we hope to do next year.”

The average level of 44 nmol/L may also be regarded as deficient. Lower levels were presumably more common among children born in winter, of lower socioeconomic status and with familial asthma or smoking histories. By 3 months, those with 25OHD levels below 25 nmol/L appeared twice as like to have developed respiratory infections as those with levels of 75 nmol/L or higher. Scientists conclude that lower the neonatal 25OHD level, higher the cumulative risk of wheezing. However no link between 25OHD levels and asthma was registered.

The study will be published in the January 2011 issue of Pediatrics.