Low Vitamin D Levels During Pregnancy May Affect Mental Health in Early Childhood

Vitamin D status during prenatal brain development may influence risk of attention deficit and hyperactivity disorder (ADHD) symptoms in childhood, according to two recent studies.

The first study, published in the Australia & New Zealand Journal of Psychiatry, found that there was an association between higher umbilical cord blood vitamin D levels and a reduced risk of ADHD symptoms exhibited in early childhood.

The study subjects included 1,233 members of a Danish population study that is following 2,500 mother and children from birth to their 18th birthday. In this study, vitamin D levels were measured in umbilical cord blood at birth, and child behavior was analyzed at an average of 2.7 years of age.

The mothers who had taken vitamin D, and had a vitamin D level in cord blood of at least 25 nmol/L (10 ng/ml) had children with lower ADHD scores. For every 10 nmol/L (4 ng/ml) increase in umbilical blood vitamin D levels, the likelihood of being among the 10% highest group of ADHD symptoms scale fell by 11%.

These results support the conclusion of another study published in 2015 in the journal Epidemiology.

The study included 1,650 mother-child pairs in Spain and showed that children born to mothers with higher vitamin D levels during pregnancy had lower scores on a ADHD symptoms scale.

Maternal blood was collected at 13 weeks gestation and analyzed for vitamin D content. Children were assessed for ADHD-like symptoms at ages 4-5 using a standardized analytical test.

After adjusting for confounding factors, the number of total ADHD-like symptoms decreased by 11% for every 25 nmol/L (10 ng/ml) increment in maternal vitamin D concentration.

The results of these studies indicate that higher maternal circulating levels of vitamin D in pregnancy are associated with lower risk of developing ADHD-like symptoms in childhood, and suggest a protective effect of prenatal vitamin D.

Mossin MH, Aaby JB, Dalgård C, Lykkedegn S, Christesen HT, Bilenberg N. Inverse associations between cord vitamin D and attention deficit hyperactivity disorder symptoms: A child cohort study. Aust N Z J Psychiatry. 2016.

Morales E, Julvez J, Torrent M, et al. Vitamin D in Pregnancy and Attention Deficit Hyperactivity Disorder-like Symptoms in Childhood. Epidemiology. 2015;26(4):458-65.