Attention Deficit Hyperactivity Disorder (ADHD) is a chronic condition including attention difficulty, hyperactivity and impulsiveness. Children of mothers who took vitamin D during pregnancy with
resultant high levels of the vitamin in the umbilical blood have fewer
symptoms of ADHD at the age of 2.5 years.
These were the findings in a new study from the Odense Child Cohort just published in The Australia & New Zealand Journal of Psychiatry
‘Children of mothers who took vitamin D during pregnancy with resultant high levels of the vitamin in the umbilical blood have fewer symptoms of ADHD at the age of 2.5 years’
"And for every 10 nmol/L increase in the vitamin D
concentration in umbilical blood, the risk of a being among the 10%
highest score on the ADHD symptom scale fell by 11%," explains one of
the study's initiators, Professor Niels Bilenberg.
1,233 children from Odense Municipality were monitored in the study.
Vitamin D was measured in umbilical blood, and mothers completed the
Child Behavior Checklist (CBCL) when their child was 2.5 years old. The
CBCL questionnaire can be used to identify early symptoms of ADHD, even
though an ADHD diagnosis cannot be made at that age.
"And the trend was clear: those mothers who had taken vitamin D,
and had a vitamin D level (25OHD) in their umbilical blood over 25
nmol/L, had children with lower ADHD scores," continues Bilenberg. "This
was after we had corrected for other factors that could explain the
link, such as the mother's age, smoking, alcohol, obesity, education,
number of children, psychiatric disease in the parents, child's sex, age
and seasonal variation."
The link between vitamin D and early ADHD symptoms has not been described before, and has therefore attracted attention.
"We were very surprised that the link was so clear," say two of
the study's other authors, medical students Jens Bull Aaby and Mats
Mossin, "as there was no previous awareness that this link could be
identified at such an early age. It's impossible to say with which
children will develop ADHD later on, but it will be interesting to
further follow up those children who were at the highest end versus the
normal range of the ADHD scale."
The study offers no explanation as to how vitamin D can protect
against ADHD, but other studies have shown that vitamin D plays an
important role in the early development of the brain.
"We had an idea about it," says Aaby, "but we cannot say with
certainty that vitamin D protects against early symptoms of ADHD. Our
study only indicates that there is a link that we cannot explain in any
Facts: Odense Børnekohorte is a joint study between Odense
University Hospital, the Psychiatric Service of the Region of Southern
Denmark, Odense Municipality, and the University of Southern Denmark. In
the study, 2,500 mothers and their children are being monitored from
early pregnancy to the child's 18th birthday. The children are now three to five
years old and a number of follow-up studies are planned.