Definition and research guide
This page combines a MeSH definition, publication statistics and selected research abstracts. It is a starting point for reading the literature, not a medical textbook or a systematic evidence review.
Content available: 3 complete abstracts (706 words), 9 references. Full article text is not stored or reproduced here; follow the PMID, DOI or PMC links to read the original sources and their access terms.
Definition
A vitamin that includes both cholecalciferols and ergocalciferols, which have the common effect of preventing or curing rickets in animals. It can also be viewed as a hormone since it can be formed in SKIN by action of ultraviolet rays upon the precursors, 7-dehydrocholesterol and ergosterol, and acts on vitamin D receptors to regulate calcium in opposition to parathyroid hormone.
Definition: NLM Medical Subject Headings (MeSH) scope note (Public domain (U.S. National Library of Medicine); attribution requested). View the MeSH record.
Where it fits in the MeSH classification
- Broader topics
- Secosteroids
- Narrower topics
- Cholecalciferol; Ergocalciferols
- See also
- Receptors, Calcitriol
Related concepts
- Cholecalciferol
- Ergocalciferols
- Rickets
- Ultraviolet Rays
- Ergosterol
- Vitamins
- Receptors
- Calcium
- Parathyroid Hormone
Research landscape
PubMed indexes 75,391 records tagged with the MeSH heading “Vitamin D” (counts retrieved 2026-10-31). 16,304 of them (21.6%) were published from 2020 onward, and the busiest period so far is 2010-2019 with 25,336 records.
Reviews account for 12,302 records (16.3%) and meta-analyses for 1,531. Randomized controlled trials number 4,671 (6.2%) as a share of all records on the topic.
Show the data
| Period | Records |
|---|---|
| through 1999 | 22,476 |
| 2000-2009 | 11,275 |
| 2010-2019 | 25,336 |
| 2020 onward | 16,304 |
Publication-type chart data
| Type | Records | Share |
|---|---|---|
| Reviews | 12,302 | 16.3% |
| Meta-analyses | 1,531 | 2.0% |
| Randomized controlled trials | 4,671 | 6.2% |
Method: PubMed query "Vitamin D"[MeSH Terms] with publication-type and date filters, retrieved 2026-10-31.
Reading the evidence in drugs and chemicals
Studies of a chemical or drug can answer very different questions: what it is and how it behaves in cells and animals, how the body handles it, and whether it changes outcomes in people. Laboratory and animal findings often do not carry over to patients, and observational studies of exposures are confounded by who uses a substance and why. Nothing on this page is a recommendation to use, avoid, start or stop any substance or medicine; talk to a qualified clinician or pharmacist about your own situation. Check the dose, the species, the comparison group and whether a patient-relevant outcome was measured.
Evidence from open-access studies
These open-access studies come from PubMed’s best-match results for this heading (papers whose main topic it is), ranked here by citation count, with one recent addition. Each abstract is reproduced in full under its recorded open licence so that you can read the authors’ own words. They illustrate the literature; they are not a systematic summary of it. Citation counts measure attention, not reliability or clinical benefit.
| Study / authors | Year | Source label / design | Europe PMC citations | Licence / source |
|---|---|---|---|---|
| Vitamin D and Health Outcomes: State-of-the-Art Review of Triangulated Evidence and Ongoing Controversies | 2026 | Review article Design not recorded in structured metadata | 8 | cc by PMID 41849024 · DOI · PMC12999768 |
| Vitamin D3 as an immunomodulatory agent: molecular mechanisms, clinical translation, and precision therapeutic strategies | 2026 | Review article Design not recorded in structured metadata | 8 | cc by PMID 41846928 · DOI · PMC12989342 |
| Vitamin D-Mediated Immunoregulation in Degenerative Diseases: Insights into Cardiovascular, Neurodegenerative and Musculoskeletal Disorders | 2026 | Review article Design not recorded in structured metadata | 4 | cc by PMID 41754146 · DOI · PMC12942877 |
Vitamin D and Health Outcomes: State-of-the-Art Review of Triangulated Evidence and Ongoing Controversies [1]
Abstract reading summary — source excerpts
- Opening excerpt
- PURPOSE OF REVIEW: Vitamin D is a pleiotropic hormone with an established role in skeletal integrity and broader actions in immune regulation, inflammation, cellular proliferation, and energy homeostasis.
- Closing excerpt
- Vitamin D should be regarded neither as a universal panacea nor as a trivial supplement, but as a context-dependent hormone whose clinical value lies in outcome-specific correction of deficiency.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (320 words)
PURPOSE OF REVIEW: Vitamin D is a pleiotropic hormone with an established role in skeletal integrity and broader actions in immune regulation, inflammation, cellular proliferation, and energy homeostasis. Despite decades of research, its extra-skeletal effects remain controversial, largely due to discordant findings across observational studies, Mendelian randomization studies (MRS), and randomized controlled trials (RCTs). Unlike many prior reviews, this state-of-the-art review synthesizes triangulated evidence across these study designs to clarify outcome-specific causal relationships and ongoing controversies. RECENT FINDINGS: Triangulated evidence provides strong and consistent support for a causal role of vitamin D in skeletal health, particularly in the prevention and treatment of rickets and osteomalacia, and in fracture risk reduction among vitamin D–deficient and older populations. For selected extra-skeletal outcomes, modest and threshold-dependent benefits are observed, including reductions in cancer mortality, protection against autoimmune disorders, most convincingly multiple sclerosis, and decreased risk of acute respiratory infections, including COVID-19, primarily in individuals with low baseline 25(OH)D concentrations. In contrast, associations with cardiovascular disease, metabolic disorders, obesity, and most neuropsychiatric outcomes are not consistently supported by genetic or interventional evidence, suggesting limited or non-causal effects. Across outcomes, evidence indicates a non-linear relationship between vitamin D status and health, with increased risk concentrated at low 25-hydroxyvitamin D concentrations and limited benefit beyond sufficiency. All-cause mortality shows a modest, threshold-dependent association, with supplementation benefits largely confined to deficient or older populations. Key challenges include assay variability, non-linear dose–response relationships, and RCT designs that frequently enroll vitamin D–replete populations, resulting in substantial methodological heterogeneity and limiting causal inference. Overall, the presented triangulated model may reconcile longstanding inconsistencies by reframing vitamin D as a context-dependent determinant of health. These findings argue against indiscriminate population-wide supplementation and support targeted strategies focused on the identification and correction of deficiency. Vitamin D should be regarded neither as a universal panacea nor as a trivial supplement, but as a context-dependent hormone whose clinical value lies in outcome-specific correction of deficiency.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 41849024 · DOI · PMC12999768
Vitamin D3 as an immunomodulatory agent: molecular mechanisms, clinical translation, and precision therapeutic strategies [2]
Abstract reading summary — source excerpts
- Opening excerpt
- Vitamin D3 (VitD3) deficiency affects over one billion individuals globally, representing a critical modifiable risk factor for immune-mediated diseases.
- Closing excerpt
- This review systematically examines the immunomodulatory mechanisms of Vitamin D3, evaluates clinical translation evidence in psoriasis, systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), type 1 diabetes mellitus (T1DM), inflammatory bowel disease (IBD), and discusses precision medicine strategies and therapeutic potential.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (187 words)
Vitamin D3 (VitD3) deficiency affects over one billion individuals globally, representing a critical modifiable risk factor for immune-mediated diseases. Beyond its classical role in calcium metabolism, Vitamin D3 orchestrates immune homeostasis through vitamin D receptor (VDR) signaling, exerting profound regulatory effects on both innate and adaptive immunity. Mechanistically, Vitamin D3 maintains the balance between antimicrobial defense and inflammatory suppression by inhibiting key pro-inflammatory pathways including nuclear factor κB (NF-κB) and the NOD-like receptor protein 3 (NLRP3) inflammasome, while activating the Nuclear Factor Erythroid 2-Related Factor 2 (Nrf2)-mediated antioxidant defense system. However, the immunomodulatory effects of Vitamin D3 exhibit significant inter-individual variability, with clinical efficacy highly dependent on patient-specific factors including serum 25-hydroxyvitamin D [25(OH)D, calcifediol] levels and VDR gene polymorphisms, driving a paradigm shift from empirical supplementation toward biomarker-guided precision medicine. Novel delivery systems-nanoemulsions, twin-screw extrusion technology, and liposomes-effectively overcome bioavailability and stability limitations of traditional preparations. This review systematically examines the immunomodulatory mechanisms of Vitamin D3, evaluates clinical translation evidence in psoriasis, systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), type 1 diabetes mellitus (T1DM), inflammatory bowel disease (IBD), and discusses precision medicine strategies and therapeutic potential.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 41846928 · DOI · PMC12989342
Vitamin D-Mediated Immunoregulation in Degenerative Diseases: Insights into Cardiovascular, Neurodegenerative and Musculoskeletal Disorders [3]
Abstract reading summary — source excerpts
- Opening excerpt
- Degenerative diseases are characterized by the gradual loss of cellular integrity, tissue function, and regenerative capacity.
- Closing excerpt
- This review explores the relationships between vitamin D and cardiovascular, neurodegenerative, and musculoskeletal diseases, with a focus on the underlying immunological and metabolic mechanisms of actions.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (199 words)
Degenerative diseases are characterized by the gradual loss of cellular integrity, tissue function, and regenerative capacity. Cardiovascular diseases, neurodegenerative disorders, and musculoskeletal deterioration are considered major categories of degenerative diseases, and vitamin D deficiency has been linked with an increased risk of these conditions. Vitamin D has the potential to modulate neurogenerative process by influencing the progression of neuronal survival, neurogenesis, and synaptic plasticity through both genomic and non-genomic mechanisms mediated by vitamin D receptors, which are widely distributed across brain regions and cell types. Additionally, vitamin D regulates brain immunometabolism by modulating microglial and astrocytic inflammatory responses and oxidative stress. Vitamin D has long been recognized as essential for bone health. Beyond its classical role, vitamin D contributes to the maintenance of bone-muscle homeostasis, enhances mitochondrial biogenesis and ATP production while reducing oxidative stress, and facilitates bidirectional bone-muscle crosstalk through myokines and osteokines to coordinate bone remodeling and muscle regeneration. However, despite these mechanistic insights, the beneficial effects of vitamin D on these diseases-such as reduced risk or mitigation of progression-remains inconclusive. This review explores the relationships between vitamin D and cardiovascular, neurodegenerative, and musculoskeletal diseases, with a focus on the underlying immunological and metabolic mechanisms of actions.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 41754146 · DOI · PMC12942877
Key reviews and meta-analyses
The most cited review-type papers among PubMed’s best-match results for this heading, listed with bibliographic details only. Follow the links for the full text and access terms.
- Research article Vitamin D supplementation to prevent acute respiratory infections: a systematic review and meta-analysis of aggregate data from randomised controlled trials [4]
- Research article Vitamin D to prevent exacerbations of COPD: systematic review and meta-analysis of individual participant data from randomised controlled trials [5]
- Research article The Association between Vitamin D Deficiency and Sleep Disorders: A Systematic Review and Meta-Analysis [6]
- Research article The link between COVID-19 and VItamin D (VIVID): A systematic review and meta-analysis [7]
- Research article Vitamin D supplementation and incident preeclampsia: A systematic review and meta-analysis of randomized clinical trials [8]
- Research article Effects of combined calcium and vitamin D supplementation on osteoporosis in postmenopausal women: a systematic review and meta-analysis of randomized controlled trials [9]
References
- Dalamaga M, Emfietzoglou R, Petropoulou D, Kypraiou M, Kounatidis DC, Vallianou NG, et al.. Vitamin D and Health Outcomes: State-of-the-Art Review of Triangulated Evidence and Ongoing Controversies. . 2026. PMID 41849024 · DOI · PMC12999768
- Liu Q, Li Z, Li S, Li Y, Pan H, Tao Y. Vitamin D3 as an immunomodulatory agent: molecular mechanisms, clinical translation, and precision therapeutic strategies. . 2026. PMID 41846928 · DOI · PMC12989342
- Lee GY, Park CY, Han SN. Vitamin D-Mediated Immunoregulation in Degenerative Diseases: Insights into Cardiovascular, Neurodegenerative and Musculoskeletal Disorders. . 2026. PMID 41754146 · DOI · PMC12942877
- Jolliffe DA, Camargo CA, Sluyter JD, Aglipay M, Aloia JF, Ganmaa D, et al.. Vitamin D supplementation to prevent acute respiratory infections: a systematic review and meta-analysis of aggregate data from randomised controlled trials. Lancet Diabetes Endocrinol. 2021. PMID 33798465 · DOI
- Jolliffe DA, Greenberg L, Hooper RL, Mathyssen C, Rafiq R, de Jongh RT, et al.. Vitamin D to prevent exacerbations of COPD: systematic review and meta-analysis of individual participant data from randomised controlled trials. Thorax. 2019. PMID 30630893 · DOI
- Gao Q, Kou T, Zhuang B, Ren Y, Dong X, Wang Q. The Association between Vitamin D Deficiency and Sleep Disorders: A Systematic Review and Meta-Analysis. Nutrients. 2018. PMID 30275418 · DOI · PMC6213953
- Bassatne A, Basbous M, Chakhtoura M, El Zein O, Rahme M, El-Hajj Fuleihan G. The link between COVID-19 and VItamin D (VIVID): A systematic review and meta-analysis. Metabolism. 2021. PMID 33774074 · DOI · PMC7989070
- Fogacci S, Fogacci F, Banach M, Michos ED, Hernandez AV, Lip GYH, et al.. Vitamin D supplementation and incident preeclampsia: A systematic review and meta-analysis of randomized clinical trials. Clin Nutr. 2020. PMID 31526611 · DOI
- Liu C, Kuang X, Li K, Guo X, Deng Q, Li D. Effects of combined calcium and vitamin D supplementation on osteoporosis in postmenopausal women: a systematic review and meta-analysis of randomized controlled trials. Food Funct. 2020. PMID 33237064 · DOI
About this article
- Sources
- NLM Medical Subject Headings (definition, synonyms); NCBI PubMed (counts, identifiers); Europe PMC (open-access abstracts and citation counts).
- Verification
- Every reference was resolved against PubMed on 2026-10-31; title, year and DOI matched.
- Review state
- automated source verified; no human expert review has been recorded yet.
- Version
- 1, last updated 2026-10-31.
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Evidence strength
EvidenceHelix's computed view of the study designs behind this topic: how common meta-analyses, randomized trials and reviews are, how recent the literature is, and a plain-language reading. It describes the design mix of the literature. It is not a quality appraisal of any study, and it is not medical advice.