Newborn babies with low vitamin D are six times as likely to develop lung infections with RSV (respiratory syncytial virus), researchers from Utrecht University Medical Center in the Netherlands reported in the journal Pediatrics. RSV is a common virus that causes lung and respiratory tract infections – the majority of children are infected with RSV by the time they are two years old.

RSV is the most common cause of pneumonia and bronchiolitis in infants in America.

Mirjam E. Belderbos, MD. and team, having already suspected that low vitamin D is closely linked to RSV vulnerability, set out to measure vitamin D levels in the cord blood of 156 newborn babies. They were then followed-up for 12 months.

They found that over one quarter of all the infants had serum levels below 20ng/mL when they were born (low vitamin D). These infants were six times as likely to develop RSV lung infection than the 46% newborns whose blood serum levels were 30ng/mL or more.

The authors wrote:

“We demonstrated that 54% of healthy newborns in the Netherlands are born with insufficient concentrations required for maximum health, and that low plasma concentrations are associated with increased risk of RSV lower-respiratory tract infections in the first year of life.”

Most western countries have similar prevalence of newborns and infants with low vitamin D.

They found that infants born in the summer months had significantly higher vitamin D levels than those born in winter. Our bodies produce more vitamin D when our skin is exposed to sunlight.

The authors concluded:

“Vitamin D deficiency in healthy neonates is associated with increased risk of RSV LRTI in the first year of life. Intensified routine vitamin D supplementation during pregnancy may be a useful strategy to prevent RSV LRTI during infancy.”

Vitamin D encourages the absorption and metabolism of phosphorous and calcium. It is a steroid vitamin. Humans who are exposed to a certain amount of sunlight each week do not require vitamin D supplements because sunlight promotes the synthesis of vitamin D in the skin.

We know about five forms of vitamin D – D1, D2, D3, D4, D5. Vitamins D2 (ergocalciferol) and D3 (cholecalciferol) appear to be the ones that matter the most to us.

According to NHANES (National Health and Nutrition Examination Survey), 9% of American kids were vitamin D deficient (<15 ng/mL), while 61% were found to be vitamin D insufficient (from 15 to 29 ng/mL). “Cord Blood Vitamin D Deficiency is Associated With Respiratory Syncytial Virus Bronchiolitis”
Mirjam E. Belderbos, MDa, Michiel L. Houben, MDa, Berry Wilbrink, PhDb, Eef Lentjes, PhDc, Eltje M. Bloemena, Jan L. L. Kimpen, MD, PhDa, Maroeska Rovers, PhDd, Louis Bont, MD, PhD
Pediatrics doi: 10.1542/peds.2010-3054

Written by Christian Nordqvist