New European research has found that children born to mothers who have a vitamin D deficiency during pregnancy may have a higher risk of developing attention-deficit/hyperactivity disorder (ADHD), one of the most common chronic diseases in children.
Carried out by researchers at the University of Turku, Finland, in collaboration with Columbia University, New York, the new study looked at 1,067 children born between 1998 and 1999 diagnosed with ADHD in Finland, and 1,067 children without ADHD who acted as controls.
The researchers also looked at data gathered on the mothers' vitamin D levels during the first and second trimester of pregnancy.
The findings, which were published in the Journal of the American Academy of Child & Adolescent Psychiatry, showed that children whose mothers had a vitamin D deficiency during the first and second trimester had a 34 percent higher risk of ADHD, compared to those whose mothers had sufficient vitamin D levels.
The results also held true even after taking into account the mother's age, socioeconomic status and psychiatric history.
The researches say that the study is the first to investigate the association between low maternal vitamin D levels in early to mid-pregnancy and a higher risk for diagnosed ADHD in the children at the population level. It provides strong evidence of an association between the two.
The current national recommendation in Finland vitamin D intake during pregnancy is 10 micrograms per day throughout the year. However, the study's primary investigator, Professor Andre Sourander, says that despite these recommendations, the vitamin D intake in Finland among mothers in several immigrant groups is not at a sufficient level. He also added that vitamin D deficiency is not only a concern in Finland, but a problem all around the world.