The impact of vitamin D supplementation on ADHD: Study

A new study in Finland investigated whether low maternal vitamin D levels during pregnancy played a role in attention-deficit/hyperactivity disorder ADHD diagnosis in offspring. 

Researchers from the University of Turku, Finland, and Columbia University, New York studied 1,067 children born in Finland between 1998 and 1999 diagnosed with ADHD and the same number of matched controls. The data was collected before the current national recommendation in Finland for the intake of vitamin D during pregnancy, which is 10 micrograms per day throughout the year.

Maternal vitamin D status was determined by collecting about 2 million samples of maternal sera from the Finnish Maternity Cohort (FMC), which collects data on virtually every pregnancy in Finland. After being absorbed through the skin or ingested, vitamin D metabolizes into 25-hydroxyvitamin D [25(OH)D], which can be measured to determine a participant’s vitamin D level. Researchers utilized quantitative immunoassay to calculate maternal vitamin D status during the first trimester of pregnancy.

Elevated Risk 

The study, published in The Journal of the American Academy of Child & Adolescent Psychiatry​, found that low vitamin D levels during pregnancy increase the risk of ADHD diagnosis in childhood. 

Researchers reported that the risk of ADHD was 34% higher in children whose mother had a vitamin D deficiency during pregnancy than in those children whose mother's vitamin D level was sufficient during the first and second trimesters. 

"Alongside genotype, prenatal factors such as vitamin D deficiency during pregnancy, can influence the development of ADHD,"​ said MD Minna Sucksdorff from the University of Turku, Finland.

While many nutritional deficiencies are on the decline across the globe, vitamin D is one deficiency that remains prevalent. Head researcher Professor Andre Sourander said low vitamin D levels is still a global problem despite the recommendations. In Finland, for example, mothers' vitamin D intake among several immigrant groups is not at a sufficient level.

Significant implications 

"This research offers strong evidence that a low level of vitamin D during pregnancy is related to attention deficiency in offspring. As ADHD is one of the most common chronic diseases in children, the research results have a great significance for public health,"​ added Sourander.

The study is part of a larger research project that aims to discover the connections between the mother's health during pregnancy and ADHD in offspring. The goal is to produce information for developing preventative treatments and measures for identifying children with ADHD risk.

While the role of supplements in ADHD sufferers remains unclear, the authors did note that if these findings can be replicated in independent samples, it could have major public health implications.

Vitamin D supplementation in children with ADHD may improve cognitive function

A 2018 study published in the Annals of Pharmacotherapy​ found that vitamin D deficiency was significantly greater in children with ADHD. The research also demonstrated that vitamin D supplementation improved cognitive function in the conceptual level, inattention, opposition, hyperactivity, and impulsivity domains.

Source: Journal of the American Academy of Child & Adolescent Psychiatry ​

(2019) DOI: https://doi.org/10.1016/j.jaac.2019.11.021​

“Maternal Vitamin D Levels and the Risk of Offspring Attention-Deficit/Hyperactivity Disorder”​

Authors: M. Sucksdorff et al.