A new study from King's College London revealed that children born from mothers who take vitamin D supplements during their pregnancy were less likely to develop asthma and respiratory infections.

The study, published in the journal Allergy and Clinical Immunology, showed that vitamin D supplements during pregnancy can positively modify the newborn's immune system, helping the child in preventing childhood asthma.

"For the first time, we have shown that higher Vitamin D levels in pregnancy can effectively alter the immune response of the newborn baby, which could help to protect the child from developing asthma," said lead researcher, Professor Catherine Hawrylowicz from King's College London, in a press release. "Future studies should look at the long-term impact on the immunity of the infant."

For the study, the researchers conducted a clinical trial involving over 50 pregnant women. The participants were randomized at 10- and 18-weeks of pregnancy to high or low doses of vitamin D supplements. One group of participants took a supplement of 4,400 IU vitamin D3 per day during their second and third trimesters, while another group served as the control and were given the recommended daily intake (RDI) of 400 IU/day.

The researchers then took blood samples from the participant's umbilical cord to test the responsiveness of the newborn's innate immune system and T lymphocyte responses. The child's innate immune system serves as the body's first line of defense against infections, while the T lymphocytes provide a longer-lasting protection.

Blood samples from the mothers with higher vitamin D intake responded to mimics of pathogen stimulation by greater innate cytokine responses and greater IL-17A production in response to T lymphocyte stimulation. Due to these responses, which are predicted to improve neonatal defense against infection, the researchers link higher dosage of vitamin D with decrease development of childhood asthma. As a direct result of this, the respiratory health of the child could significantly improve.

According to Centers for Disease Control and Prevention, about 8.4 percent of children below the age of 18 in the United States have asthma.