SynthesisEuropean journal of nutrition2023
Long-term supplementation with 3200 to 4000 IU of vitamin D daily and adverse events: a systematic review and meta-analysis of randomized controlled trials.
Synthesis in European journal of nutrition, 2023. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 31 papers, 4 of them syntheses 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
31 citing papers in PubMed, 4 syntheses or guidelines pooled it, 34 citations in OpenAlex.
- The 2024 Endocrine Society Guideline on Vitamin D: Comprehensive Summary and Critical Appraisal.Nutrients · 2026Pooled it
- A systematic review of evidence-based clinical guidelines for vitamin D screening and supplementation over the last decade.Archives of public health = Archives belges de sante publique · 2025Pooled it
- Pooled it
- Optimal methods of vitamin D supplementation to prevent acute respiratory infections: a systematic review, dose-response and pairwise meta-analysis of randomized controlled trials.Nutrition journal · 2024Pooled it
- A 12-week double-blind randomised controlled trial investigating the effect of dietary supplementation with 125The British journal of nutrition · 2024Trial
- Pharmacokinetics Modelling Reveals Inconsistency Between the US and European Vitamin D Safety Guidelines.Biomedicines · 2026Article
- The potential of vitamins in Huntington's disease: bridging mechanistic evidence with translational limitations and future strategies.Metabolic brain disease · 2026Review
- Epigenetic Mechanisms of Vitamin D in the Aging Process: A Narrative Review.International journal of molecular sciences · 2026Review
- From the Vitamin D Paradox to Precision Nutrition: Targeted Supplementation, Assay Pitfalls, and Clinical Decision-Making.Current nutrition reports · 2026Review
- Response to Comment on Wagner et al. Beyond Glucose-Rethinking Prediabetes for Precision Prevention.Diabetes care · 2026Article
- Vitamin D and Hemopoietic Stem Cell Transplantation: Clinical Guidance for GVHD Management and Post-Transplant Outcomes.Cancers · 2026Review
- Comparison of tWo hospital quality Improvement interventions on inappropriate measurement and SupplEmentation of vitamin D: the WISE-D study.BMC geriatrics · 2026Article
- Vitamin D and Diabetes: Exploring the Link, Prevention, and Management.Current medicinal chemistry · 2026Review
- Vitamin D and exercise in obesity: a neurovascular-muscle axis.Frontiers in nutrition · 2026Review
- CYP24A1 Deficiency Presenting With Hypercalcemia and Hypervitaminosis D in Pregnancy: A Case Report.Cureus · 2026Article
- Association between serum 25(OH)D, oxidative balance score, and mortality among individuals with metabolic syndrome: a cohort study.Diabetology & metabolic syndrome · 2025Article
- Rethinking Vitamin D Deficiency: Controversies and Practical Guidance for Clinical Management.Nutrients · 2025Review
- Vitamin D and the aging skin: insights into oxidative stress, inflammation, and barrier function.Immunity & ageing : I & A · 2025Review
- Vitamin D Supplementation in the Czech Republic: Socioeconomic Determinants and Public Awareness Gaps.Nutrients · 2025Article
- Regulation of Renal and Extrarenal Calcitriol Synthesis and Its Clinical Implications.International journal of molecular sciences · 2025Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
4 authors at 2 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
purposeThe upper tolerable intake level for vitamin D in the general population has been set at 4000 international units (IU) daily, but considerable uncertainty remains. We summarized reported harmful effects of a daily vitamin D supplement of 3200-4000 IU in trials lasting ≥ 6 months.
methodsWe performed a systematic review and meta-analysis of randomized controlled trials in several databases and identified 22 trials reporting safety data. Parameters of calcium metabolism, falls, hospitalization, and mortality were assessed.
resultsThe selected trials comprised a total number of 12,952 participants. All trials used supplemental vitamin D
conclusionSupplemental vitamin D doses of 3200-4000 IU/d appear to increase the risk of hypercalcemia and some other adverse events in a small proportion of individuals, indicating that this dose is not completely safe. In future studies, rigorous reporting of safety-related outcomes is needed when using moderately high doses of vitamin D.
Indexed as
Identifiers
What Socratic 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 Socratic graph.