Vitamin D3
Vitamin ·Exploratory record · not publication-reviewed ·Updated July 13, 2026
The sunshine vitamin, essential for calcium absorption, bone health, immune function, and mood regulation. Most people are deficient, especially in northern latitudes.
Exploratory record, not a reviewed medical publication.
See the editorial and medical-review policies for the publication gate.
This generated database record has not completed a claim-level review by a qualified human medical reviewer. Bibliography links and evidence labels are not approval. The page remains available for reference and is excluded from search indexing.
What the research says.
A quick, data-only summary. The full evidence, dosing, and sources are below.
Vitamin D3 is a vitamin most often used for bone health, immune support, mood regulation (primarily in deficient individuals). NutriStack rates the overall evidence as strong. A typical adult dose is 1,000–4,000 IU daily (5,000 IU under medical guidance), commonly taken as d3 (cholecalciferol) preferred over d2 (ergocalciferol). This profile indexes 21 sources.
The bottom line
Evidence rating strong. Most-documented uses: bone health, immune support, mood regulation (primarily in deficient individuals). 21 sources indexed (2017–2024), with 0 interaction records on file.
How it works, mechanistically.
Core mechanism
Converted to calcidiol (25-OH-D) in the liver, then to calcitriol (1,25-OH2-D) in the kidneys. Calcitriol acts as a hormone, binding to vitamin D receptors (VDR) in nearly every cell, regulating calcium/phosphorus absorption and immune cell function.
Dosing & protocol.
What it actually costs.
Real-world pricing across three quality tiers. Assumes Softgel / Oil-Based D3.
Assumes a 1,000-4,000 IU daily maintenance dose. Vitamin D3 remains one of the cheapest supplements in the database on a per-effective-dose basis. Updated 2026-04-02.
The same dose, as food.
How much you'd eat to match a supplemental dose.
Fortified foods help, but oily fish or sunlight usually matter more.
Food alone rarely covers therapeutic vitamin D targets.
Therapeutic-style vitamin D intakes are difficult to get from food alone.
Full safety detail.
Sources, by evidence tier.
Numbered references. Citations throughout the page link here.
Meta-analyses & systematic reviews
13- 1Effect of Vitamin D3 Supplementation on Severe COVID-19: A Meta-Analysis of Randomized Clinical TrialsPMIDSobczak M, Pawliczak R · Nutrients · 2024
Sobczak M, Pawliczak R. Effect of Vitamin D3 Supplementation on Severe COVID-19: A Meta-Analysis of Randomized Clinical Trials. Nutrients. 2024
- 2Comparison of the Effect of Daily Vitamin D2 and Vitamin D3 Supplementation on Serum 25-Hydroxyvitamin D Concentration (Total 25(OH)D, 25(OH)D2, and 25(OH)D3) and Importance of Body Mass Index: A Systematic Review and Meta-AnalysisPMIDvan den Heuvel EG, Lips P, Schoonmade LJ et al. · Advances in nutrition (Bethesda, Md.) · 2024
van den Heuvel EG, Lips P, Schoonmade LJ et al.. Comparison of the Effect of Daily Vitamin D2 and Vitamin D3 Supplementation on Serum 25-Hydroxyvitamin D Concentration (Total 25(OH)D, 25(OH)D2, and 25(OH)D3) and Importance of Body Mass Index: A Systematic Review and Meta-Analysis. Advances in nutrition (Bethesda, Md.). 2024
- 3Long-term supplementation with 3200 to 4000 IU of vitamin D daily and adverse events: a systematic review and meta-analysis of randomized controlled trialsPMIDZittermann A et al. · Eur J Nutr · 2023
Vitamin D3 at 3200-4000 IU/day appears to increase the risk of hypercalcemia (4 per 1000) and some adverse events in a small proportion of individuals
- 4Effects of Whey Protein, Leucine, and Vitamin D Supplementation in Patients with Sarcopenia: A Systematic Review and Meta-Analysis.PMIDChang MC, Choo YJ · Nutrients · 2023
Combined supplementation with whey protein, leucine, and vitamin D improved muscle mass and physical performance in patients with sarcopenia.
- 5What is the impact of daily oral supplementation of vitamin D3 (cholecalciferol) plus calcium on the incidence of hip fracture in older people? A systematic review and meta-analysisPMIDManoj P, Derwin R, George S · International journal of older people nursing · 2023
Manoj P, Derwin R, George S. What is the impact of daily oral supplementation of vitamin D3 (cholecalciferol) plus calcium on the incidence of hip fracture in older people? A systematic review and meta-analysis. International journal of older people nursing. 2023
- 6Vitamin D3 and COVID-19 Outcomes: An Umbrella Review of Systematic Reviews and Meta-AnalysesPMIDPetrelli F, Oldani S, Borgonovo K et al. · Antioxidants (Basel, Switzerland) · 2023
Petrelli F, Oldani S, Borgonovo K et al.. Vitamin D3 and COVID-19 Outcomes: An Umbrella Review of Systematic Reviews and Meta-Analyses. Antioxidants (Basel, Switzerland). 2023
- 7Effect of supplemental vitamin D3 on bone mineral density: a systematic review and meta-analysisPMIDElkhidir AE et al. · Nutr Rev · 2022
Systematic review assessing the effect of vitamin D3 supplementation on bone mineral density across multiple RCTs
- 8The effect of vitamin D supplementation on depressive symptoms in adults: A systematic review and meta-analysis of randomized controlled trialsPMIDCheng YC et al. · Crit Rev Food Sci Nutr · 2022
Vitamin D supplementation reduced depressive symptoms more in those with existing depression (SMD: -0.57) than in the general population
- 9Vitamin D deficiency in children and adolescents with obesity: a meta-analysis.PMIDFiamenghi VI, Mello ED · Jornal de pediatria · 2021
Significantly higher prevalence of vitamin D deficiency in children and adolescents with obesity compared to non-obese peers.
- 10Vitamin D Supplementation and Cardiovascular Disease Risks in More Than 83,000 Individuals in 21 Randomized Clinical Trials: A Meta-analysisPMIDBarbarawi M et al. · JAMA Cardiol · 2019
No significant reduction in major adverse cardiovascular events or cancer incidence; cancer mortality reduced in some subgroups with longer follow-up
- 11Association between vitamin D supplementation and mortality: systematic review and meta-analysis.PMIDZhang Y, Fang F, Tang J et al. · BMJ · 2019
Vitamin D supplementation was associated with a statistically significant reduction in all-cause mortality in a meta-analysis of randomized controlled trials.
- 12Effects of vitamin D supplementation on musculoskeletal health: a systematic review, meta-analysis, and trial sequential analysisPMIDBolland MJ et al. · Lancet Diabetes Endocrinol · 2018
Vitamin D supplementation did not prevent fractures or falls or have clinically meaningful effects on bone mineral density in unselected community-dwelling adults
- 13Vitamin D supplementation to prevent acute respiratory infections: systematic review and meta-analysis of individual participant dataPMIDMartineau AR et al. · BMJ · 2017
Vitamin D supplementation reduced the risk of acute respiratory tract infection (OR 0.88); greatest benefit in those with baseline 25-OHD <25 nmol/L and with daily/weekly dosing
Randomized controlled trials
6- 14Effects of cholecalciferol supplementation on depressive symptoms, C-peptide, serotonin, and neurotrophin-3 in type 2 diabetes mellitus: A double-blind, randomized, placebo-controlled trialPMIDPutranto R, Setiati S, Nasrun MW et al. · Narra J · 2024
Putranto R, Setiati S, Nasrun MW et al.. Effects of cholecalciferol supplementation on depressive symptoms, C-peptide, serotonin, and neurotrophin-3 in type 2 diabetes mellitus: A double-blind, randomized, placebo-controlled trial. Narra J. 2024
- 15Effect of Long-term Vitamin D3 Supplementation vs Placebo on Risk of Depression or Clinically Relevant Depressive Symptoms and on Change in Mood Scores: A Randomized Clinical TrialPMIDOkereke OI et al. · JAMA · 2020
Among 18,353 adults aged 50+, vitamin D3 vs placebo did not result in statistically significant difference in incidence of depression or mood score changes over 5.3 years
- 16Effect of vitamin D3 supplements on development of advanced cancer: secondary analysis of the VITAL randomized clinical trialChandler PD, Chen WY, Ajala ON et al. · JAMA Netw Open · 2020
- 17Vitamin D and calcium supplementation and cancer incidence in postmenopausal women: a randomized clinical trialSource linkedPMIDLappe JM, Travers-Gustafson D, Davies KM et al. · JAMA · 2017
- 18High-dose monthly vitamin D supplementation and cognitive function in older adultsPettersen JA · J Nutr Health Aging · 2017
- 19Vitamin D supplementation improves mood in women with type 2 diabetesSource linkedPMIDPenckofer S, Byrn M, Adams W et al. · J Diabetes Res · 2017
Reviews & position papers
1- 20Immunologic Effects of Vitamin D on Human Health and DiseasePMIDCharoenngam N et al. · Nutrients · 2020
Vitamin D exerts immunomodulatory activities on innate and adaptive immune systems; low 25-OHD associated with increased risk of autoimmune diseases and infections
Common questions.
Quick answers about Vitamin D3, drawn from the data on this page.
What is Vitamin D3?
The sunshine vitamin, essential for calcium absorption, bone health, immune function, and mood regulation. Most people are deficient, especially in northern latitudes.
What is Vitamin D3 used for?
Commonly cited benefits of Vitamin D3 include: Bone health; Immune support; Mood regulation (primarily in deficient individuals); Muscle function. NutriStack rates the overall evidence as strong.
What is a typical dose of Vitamin D3?
A typical adult dose of Vitamin D3 is 1,000–4,000 IU daily (5,000 IU under medical guidance). The commonly recommended form is D3 (cholecalciferol) preferred over D2 (ergocalciferol). These are general ranges, not personalized advice; confirm the right dose with a clinician.
What are the side effects of Vitamin D3?
Reported side effects include hypercalcemia at very high doses, nausea, kidney stones (rare). This is educational information; check with a healthcare professional before use.
How strong is the evidence for Vitamin D3?
NutriStack rates this as Strong, meaning multiple high-quality meta-analyses or systematic reviews converge on the same finding. Full tier criteria are at https://nutristackapp.com/methodology/evidence-tiers.
Deep dives & adjacent profiles.
This page is educational. Do not start, stop, or change a supplement or medication based on it without checking with a qualified healthcare professional.
Use this with your stack
Vitamin D3 in NutriStack.
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