Newborn vitamin D levels in relation to autism spectrum disorders and intellectual disability: A case-control study in california.
Newborn vitamin D levels do not forecast later autism or intellectual disability.
01Research in Context
What this study did
Doctors checked vitamin D in newborn blood spots. They compared kids later diagnosed with autism or intellectual disability to kids without those diagnoses.
The study used California state records. It matched cases and controls for birth year and sex.
What they found
Vitamin D levels at birth did not predict autism or intellectual disability. The odds ratios stayed near 1.0 after adjusting for other factors.
In plain words: low or high vitamin D in the first days of life did not change later diagnosis risk.
How this fits with other research
Smit et al. (2019) ran a near-identical study the same year. They also found no overall link, giving a direct replication.
Lee et al. (2022) moved the question earlier, looking at moms who took prenatal vitamins in month one of pregnancy. Again, no significant ASD difference appeared.
Mazahery et al. (2019) looks contradictory at first glance. They gave vitamin D supplements to preschoolers and saw small social gains. The key difference: they treated, they did not predict. Newborn status and later pills answer different questions.
Why it matters
You can stop using newborn vitamin D as a red flag for autism risk in well-nourished populations. Focus assessment and early intervention resources on behavioral markers instead of this lab value. When parents ask about vitamins, point them to pediatric guidelines, not fear of autism.
Want CEUs on This Topic?
The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.
Join Free →Remove vitamin D lab requests from your intake checklist for autism risk; rely on behavioral screening tools instead.
02At a glance
03Original abstract
Vitamin D deficiency has been increasing concurrently with prevalence of autism spectrum disorders (ASD), and emerging evidence suggests vitamin D is involved in brain development. Most prior studies of ASD examined vitamin D levels in children already diagnosed, but a few examined levels during perinatal development, the more likely susceptibility period. Therefore, we examined newborn vitamin D levels in a case-control study conducted among births in 2000-2003 in southern California. Children with ASD (N = 563) or intellectual disability (ID) (N = 190) were identified from the Department of Developmental Services and compared to population controls (N = 436) identified from birth certificates. 25-hydroxyvitamin D (25(OH)D) was measured in archived newborn dried blood spots by a sensitive assay and corrected to sera equivalents. We categorized 25(OH) D levels as deficient (<50 nmol/L), insufficient (50-74 nmol/L), and sufficient (≥75 nmol/L), and also examined continuous levels, using logistic regression. The adjusted odds ratios (AOR) and 95% confidence intervals for ASD were 0.96 (0.64-1.4) for 25(OH)D deficiency (14% of newborns) and 1.2 (0.86-1.6) for insufficiency (26% of newborns). The AORs for continuous 25(OH)D (per 25 nmol/L) were 1.0 (0.91-1.09) for ASD and 1.14 (1.0-1.30) for ID. Thus, in this relatively large study of measured newborn vitamin D levels, our results do not support the hypothesis of lower 25(OH)D being associated with higher risk of ASD (or ID), although we observed suggestion of interactions with sex and race/ethnicity. 25(OH)D levels were relatively high (median 84 nmol/L in controls), so results may differ in populations with higher prevalence of low vitamin D levels. Autism Res 2019, 12: 989-998. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: We studied whether vitamin D levels measured at birth were related to whether a child later developed autism (or low IQ). Our results did not show that children with autism, or low IQ, overall had lower vitamin D levels at birth than children without autism. Vitamin D levels were fairly high, on average, in these children born in Southern California.
Autism research : official journal of the International Society for Autism Research, 2019 · doi:10.5402/2012/691486