Cholecalciferol in pregnancy and child autism and ADHD
What it found
In this trial in people, high-dose cholecalciferol (vitamin D3) taken during pregnancy did not change the children's risk of autism or ADHD at age 10.
Higher vitamin D levels in the mothers before the trial started were linked to lower risk of autism and ADHD.
What they found
Studies in people
Autism and ADHD rates
Among the 591 children evaluated at age 10, 16 children (2.7%) were diagnosed with autism and 65 (11.0%) with ADHD. Of the 496 children in the vitamin D3 trial, 12 (2.4%) had autism and 58 (11.7%) had ADHD.
High-dose supplement effect
Taking high-dose vitamin D3 during pregnancy was not linked to the risk of autism or ADHD in the children.
Pre-trial vitamin D levels
Higher vitamin D levels in the mothers before the trial started were linked to a lower risk of autism, lower autistic symptom load, and lower risk of ADHD diagnosis.
What the authors conclude
“Higher maternal preintervention 25(OH)D was associated with a decreased risk of autism, lower autistic symptom load, and decreased risk of ADHD diagnosis, but high-dose vitamin D3 supplementation in pregnancy had no effect on risk of autism and ADHD.”
Also in their conclusions
- They conclude that higher maternal preintervention 25(OH)D was associated with a decreased risk of autism, lower autistic symptom load, and decreased risk of ADHD diagnosis.
- They state that high-dose vitamin D3 supplementation in pregnancy had no effect on risk of autism and ADHD.
How it was done
Vitamin D deficiency in pregnancy may increase the risk of autism and attention deficit hyperactivity disorder (ADHD).
The trial was part of a study of 700 healthy mother-child pairs enrolled at week 24 of pregnancy. Of these, 623 mothers were split into two groups: 315 took a high dose of vitamin D3 (2800 IU per day) and 308 took a standard dose (400 IU per day) until one week after giving birth. At age 10, the children were checked for autism and ADHD.
What it can’t tell you
- We summarised it from the abstract only.
- This trial can show cause and effect for the supplement dose tested, but it cannot show whether other doses or timing would make a difference.
- The link between higher pre-trial vitamin D levels and lower risk of autism and ADHD is an association, not proof that raising vitamin D levels causes the risk to drop.
Who paid
- Funding
- Funded by European Research Council (from the PubMed record).
- Authors work at
- University of Copenhagen, Denmark; Copenhagen University Hospital - Mental Health Services CPH, Denmark; University of Southern Denmark, Denmark
The paper
- Title
- High-dose vitamin D3 supplementation in pregnancy and risk of neurodevelopmental disorders in the children at age 10: A randomized clinical trial
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Abstract only
- Cite
- Aagaard K, Møllegaard Jepsen JR, Sevelsted A, et al (2024). High-dose vitamin D3 supplementation in pregnancy and risk of neurodevelopmental disorders in the children at age 10: A randomized clinical trial. The American journal of clinical nutrition. doi:10.1016/j.ajcnut.2023.12.002PubMed 38072183DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error