ArticleBiological psychology2021
Vitamin D levels in children with attention deficit hyperactivity disorder: Association with seasonal and geographical variation, supplementation, inattention severity, and theta:beta ratio.
Article in Biological psychology, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 6 papers, 1 of them a synthesis that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
6 citing papers in PubMed, 1 synthesis or guideline pooled it, 10 citations in OpenAlex.
- Effects of the δ-aminolevulinic acid dehydratase polymorphism rs1800435 on blood lead levels: a new systematic review and meta-analysis.Scientific reports · 2025Pooled it
- Review
- Fat-soluble vitamin deficiency in children with neurodevelopmental disorders: a cross-sectional study.BMC medicine · 2026Article
- Vitamin D insufficiency and sleep disturbances in children with ADHD: a case-control study.Frontiers in psychiatry · 2025Article
- Co-Occurrence of Tic Disorders and Attention-Deficit/Hyperactivity Disorder-Does It Reflect a Common Neurobiological Background?Biomedicines · 2022Review
- Vitamin D and the Central Nervous System: Causative and Preventative Mechanisms in Brain Disorders.Nutrients · 2022Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
8 authors at 4 institutions in 1 country.
Funding
Abstract
We examined seasonal and geographic effects on vitamin D [25(OH)D] levels, association with attention-deficit/hyperactivity disorder (ADHD) symptom severity, and effects of supplementation in 222 children age 7-10 with rigorously diagnosed ADHD. 25(OH)D insufficiency rates were 47.2 % in Ohio and 28.5 % 400 miles south in North Carolina. Nadir of 25(OH)D levels was reached by November in Ohio, not until January in NC. Thirty-eight children with insufficiency/deficiency took vitamin D (1000-2000 IU/day for a month); levels rose 52 %. Although inattention did not correlate with 25(OH)D at screen nor improve significantly with supplementation, inattention improvement after supplementation correlated with 25(OH)D increase (rho = 0.41, p = 0.012). A clinically significant proportion of children with ADHD have insufficient 25(OH)D even at summer's end, more so in the winter and north of the 37th parallel. The significant correlation of inattention improvement with 25(OH)D increase suggests further research on 25(OH)D as ADHD treatment.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.