A new study published in the journal ofNature Pediatric Researchrevealed that by the age of 4, low maternal vitamin D may have a major negative impact on the neurocognitive development of children. An important micronutrient that is necessary for bone formation and calcium homeostasis management is vitamin D. In addition to its critical role in skeletal growth, vitamin D has several biological activities that are essential to neurodevelopment and function. These include regulating the metabolism of neurotrophic and neurotoxic factors, regulating gene expression, signaling in cell differentiation and synaptic formation, and providing protection during inflammation of the brain. Among Indians, especially pregnant women, vitamin D deficiency is very common despite the country's abundance of sunshine. There is little research on the connection between a mother's vitamin D levels during pregnancy and the cognitive function of her unborn child. Pregnancy-related hypovitaminosis D can impact fetal brain development and result in neurocognitive problems. After adjusting for confounding factors, this study examined the relationship between vitamin D levels during pregnancy and the neurocognitive functioning of 289 mother-child couples. Prenatal serum 25-hydroxyvitamin D (25(OH)D) concentrations were assessed during the first and third trimesters, and at age 4, the offspring were subjected to a neurocognitive evaluation using the Behavior Rating Inventory of Executive Function—Preschool Version (BRIEF-P), subtests of the Developmental Neuropsychological Assessment-II (NEPSY-II), and the Wechsler Preschool and Primary Scale of Intelligence—Fourth Edition (WPPSI-IV). Data on lifestyle, mother mental health, obstetrics, sociodemographics, and parental intellectual performance were gathered. According to the adjusted regression models, lower Visual-Motor Precision of the NEPSY-II was linked to inadequate 25(OH)D levels during pregnancy. The behavioral and cognitive tests found worse executive functioning in the third trimester was linked to insufficient 25(OH)D levels. In particular, poorer scores were noted in the metacognitive index, inhibition on the BRIEF-P, and working memory on the WPPSI-IV. Overall, sustaining enough prenatal 25(OH)D may encourage the best possible neurocognitive development in the early years. The requirement for appropriate vitamin D during pregnancy is highlighted by the fact that third-trimester deficit was connected to lower executive functioning, working memory, inhibition, and metacognitive skills, while inadequate levels of 25-hydroxyvitamin D throughout pregnancy were linked to poor visual-motor accuracy. Voltas, N., Cendra-Duarte, E., Canals, J., & Arija, V. (2025). Vitamin D status during pregnancy and child neurocognitive functioning at 4 Years. Pediatric Research, 1–10.https://doi.org/10.1038/s41390-025-04258-9