Vitamin D in pregnancy may help to protect children against asthma

Research has revealed that Vitamin D supplements taken during pregnancy can have a positive effect on a newborn's immune system and protect against childhood asthma.

A research team from King’s College London have found that mums-to-be who take Vitamin D supplements during pregnancy can positively alter the immune system of their baby, which could help to protect against asthma and respiratory infections - a known risk factor for developing asthma in childhood. Professor Catherine Hawrylowicz, the study's lead researcher, explains:

"The majority of all asthma cases are diagnosed in early childhood implying that the origin of the disease stems in foetal and early life. Studies to date that have investigated links between vitamin D and immunity in the baby have been observational. 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."

Expectant mums who took part in the research were randomised between 10 - 18 weeks of pregnancy to high or low doses of vitamin D supplements. The team then took umbilical cord bloods from 51 pregnant women to test the responsiveness of the newborn’s innate immune system, which form the body’s first line of defence to infection. The team found that blood samples from babies born to mums supplemented with higher vitamin D3 were linked with an improved neonatal defence to infection.  Given the evidence for strong immune responses in early life being associated with decreased development of asthma, the team believe the effect will likely lead to improved respiratory health in childhood. Dr Samantha Walker, director of research and policy at Asthma UK, says that Vitamin D is a promising area of research for asthma, however, this study is just the first step of many needed to explore this topic:

"Although this study shows that vitamin D supplementation in pregnancy may improve immune responses, much more research is needed to prove whether this does in fact lead to reduced asthma rates later in life. Years of underfunding in [asthma] research mean that we still do not understand what causes asthma, or have the ability to predict which babies will go on to develop asthma. This is urgently needed if we are to develop strategies to treat, and ultimately prevent asthma in children."