ArticleSleep medicine: X2021
No improvement of sleep from vitamin D supplementation: insights from a randomized controlled trial.
Article in Sleep medicine: X, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 7 papers.
What it found
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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
7 citing papers in PubMed.
- Vitamin D Supplementation and Improvement in Insomnia Symptoms Among Malaysian Women With Vitamin D Deficiency: Protocol for a Randomized Controlled Trial.JMIR research protocols · 2026Article
- The associations of insomnia symptoms and clinical features as well as blood metabolic parameters in adolescents with major depressive disorders.European archives of psychiatry and clinical neuroscience · 2026Article
- Predictors of vitamin D deficiency and quality of life in obese patients with obstructive sleep apnea.Scientific reports · 2026Article
- Vitamin D and Sleep Disorders.Advances in experimental medicine and biology · 2026Review
- Do not sleep on vitamin D: vitamin D is associated with sleep variability in apparently healthy adults.American journal of physiology. Regulatory, integrative and comparative physiology · 2025Article
- Iron Deficiency and Vitamin D Deficiency Are Associated with Sleep in Females of Reproductive Age: An Analysis of NHANES 2005-2018 Data.The Journal of nutrition · 2024Article
- Vitamin D, Menopausal Health and COVID-19: Critical Appraisal of Current Data.Journal of clinical medicine · 2023Review
Corrections and comments
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Authors and funding
4 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundVitamin D has been linked to sleep health in observational studies. Data from randomized controlled trials (RCTs) with vitamin D is scarce.
methodsThis study presents the results of a secondary analysis of 189 vitamin D insufficient participants (47.1% women) in a previously performed RCT, of which 92 were randomized to vitamin D (100,000 IU (2500 μg) as a bolus dose followed by 20,000 IU (500 μg) per week), and 97 to placebo. At baseline and after 4 months at the end of the study serum 25-hydroxyvitamin D (s-25(OH)D) was measured, and the study questionnaire assessing sleep duration, daytime sleepiness, and symptoms of insomnia, was completed.
resultsAt baseline, mean s-25(OH)D was 35.0 ± 11.8 and 35.5 ± 13.3 nmol/L in the vitamin D and placebo groups, respectively. After four months, we found no statistically significant differences between the intervention groups in any of the assessed sleep outcomes, neither when stratified by sex, nor when performed in subgroups based on baseline or end of study s-25(OH)D level or presence of sleep complaints at baseline.
conclusionsWe were not able to demonstrate a significant effect of vitamin D supplementation on sleep in this vitamin D insufficient population.
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Registered trials
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