Vitamin D3 · Vitamin D3 (Cholecalciferol)
Cheap, safe, and correcting a deficiency you probably have.
Short answer
Vitamin D3 (Vitamin D3 (Cholecalciferol)) is a foundational with evidence grade A, meaning it is well-supported by replicated human trials. We track 17 produkter containing Vitamin D3. Typical doses range from 0.02 to 1 mg per portion. The top-ranked product scores 8.6 out of 10 on our composite scale (dose, evidence, price, testing, transparency). Prices range up to $55.95 per månad.
Top Vitamin D3 produkter
| Product | Varumärke | Dose | Pris/mo | 3rd-party tested | Poäng |
|---|---|---|---|---|---|
| Ultimate Omega-D3 2X | 0.025 mg | $55.95 | Yes | 8.6 | |
| Vitamin D3+K2 | 0.05 mg | $19.95 | Yes | 8.3 | |
| UnoCardio 1000 + Vitamin D | 0.025 mg | $49.95 | Yes | 7.9 | |
| Vitamin D3 5000 | 0.125 mg | $24.95 | Yes | 7.6 | |
| Basic Nutrients 2/Day | 0.05 mg | $32.00 | Yes | 7.4 |
Scores are editorial judgments, not a scientific standard. Se how we score.
What it is
A hormone your skin makes from sunlight. Most people outside the tropics who don't tan or eat a lot of oily fish are deficient, especially in winter.
Why people take it
Correcting deficiency (blood 25-OH-D < 30 ng/mL) reduces bone-fracture risk and probably respiratory infection risk. The evidence gets weaker the higher you push blood levels.
Our verdict
Test-then-treat is the right approach. If your level is <30 ng/mL, supplement 2000 to 5000 IU/day. Above 50 ng/mL, more isn't better.
Structure & class
Cholecalciferol, converted to 25-OH-D in liver, 1,25-(OH)₂-D in kidney. Nuclear receptor ligand.
Mechanism & clinical data
VITAL trial (2018) showed limited benefit at 2000 IU/day in a general (mostly D-sufficient) population but strong evidence for fracture prevention in deficient older adults. K2 co-supplementation prevents arterial calcium deposition at high doses.
Pharmacokinetics
~15 days (25-OH-D storage form).
Dose & forms
What to watch out for
Taking without fat = poor absorption. High-dose D3 without K2 can drive calcium into arteries. D2 form (ergocalciferol) is inferior for raising blood levels.
Säkerhet limits and interactions
When a product exceeds the UL or contains an ingredient with clinically significant interactions, a "Review advised" flag appears on its product page and links here.
Source: https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/
Where this dose comes from
The trial dose above is our editorial pick from the published human trials for this ingredient. We choose the dose that the best-available studies used on the endpoint most relevant to longevity. The range shows the lowest and highest doses tested in published trials. The landmark studies below are the papers we read to set it. You can click through and check our work.
When new trials publish, our automated sweeps flag them. If a new study materially changes the dose, we update it through editorial review and record the old dose, new dose, and the triggering study in every affected product's recommendation history. The dose is never changed automatically.
Regelverk status
Timeline
Regelverk events, evidence grade changes, and key research milestones for Vitamin D3, most recent first. Every entry links to its primär source.
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EU Court sharpens the bar for botanical health claimsA Court of Justice of the European Union ruling in april 2025 further tightened the requirements for how botanical ingredients (herbs, plant extracts) can be marketed with health claims in the EU, effectively removing much of the flexibility of the on-hold list.
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EU report identifies 117 supplement substances as potential health risksThe HoA Working Group on Food Supplements (26 European countries) published its first report evaluating 117 substances used in food supplements. Of these, 65 were assessed as likely novel foods, 6 were already regulated, 34 had insufficient data, and 12 were prioritized for Article 8 restriction under Regulation (EC) No 1925/2006. The 12 priority substances include ashwagandha, curcumin, melatonin, piperine, St. John's wort, coumarin, p-synephrine, maca, holy basil, Melaleuca, black cohosh, and L-tryptophan. The report drew on 1,500 RASFF alerts reviewed between 2017 and mid-2022.
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VITAL Trial 20185-year 2000 IU/day showed selective benefits in cancer mortality and cardiovascular events in specific subgroups.
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FDA authorises health claim for calcium + vitamin D and osteoporosisThe FDA published a final rule (73 FR 56477) amending 21 CFR 101.72 to include vitamin D in the calcium and osteoporosis health claim. The authorised claim states: "Adequate calcium and vitamin D throughout life, as part of a well-balanced diet, may reduce the risk of osteoporosis." Foods must contain at least 200 mg calcium and 80 IU vitamin D per portion. The rule became effective januari 1, 2010.
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EU Health Claims Regulation adoptedRegulation (EC) No 1924/2006 laid down harmonised rules for nutrition and health claims made on foods, including supplements. Only claims listed in the EU Register of authorised claims can be used. Rejected botanical claims are held in a separate on-hold list.
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EU introduces the Novel Food RegulationRegulation (EC) No 258/97 required any food or food ingredient without a history of consumption in the EU before 15 maj 1997 to be authorised before being placed on the market. This is the framework that captures NMN, spermidine as a supplement ingredient, urolithin A, and many other longevity actives.
Vitamin D3 regulates calcium absorption and immune signaling, cutting cancer death risk modestly but not preventing cancer or heart disease itself.
Verified 2026-08-02. We update this section as new peer-reviewed trials land.
Best-supported claim
Vitamin D's best-supported human benefit is a modest reduction in cancer death, not cancer incidence. A 2019 metaanalys (VITAL and prior trials) and a 2019 BMJ metaanalys of 50 trials and 74,655 participants both found vitamin D supplementation significantly reduced cancer death risk (RR 0.85) with no effect on all-cause or cardiovascular mortality (https://pmc.ncbi.nlm.nih.gov/articles/PMC6689821/). For fracture and fall prevention, a metaanalys of 32 studies found daily doses of 800-1,000 IU (not higher or lower doses) reduced osteoporotic fracture risk by 13% and fall risk by 9% (https://pmc.ncbi.nlm.nih.gov/articles/PMC9081312/). A separate metaanalys of 42 RCTs found vitamin D reduced all-cause mortality by 6% (RR 0.94) specifically in trials with over 3 years of follow-up, in people with baseline vitamin D insufficiency, and with cholecalciferol (D3) rather than ergocalciferol (D2) (https://pmc.ncbi.nlm.nih.gov/articles/PMC3857784/).
Not supported by the evidence base
Vitamin D is widely marketed as broad protection against cancer, heart disease, and infections, but the largest and best-designed trial to date, VITAL, directly contradicts the primary-prevention claim. In 25,871 healthy adults followed for a median 5.3 years, vitamin D3 at 2000 IU/day did not significantly reduce total invasive cancer incidence (HR 0.96) or major cardiovascular events (HR 0.97) (https://www.nejm.org/doi/full/10.1056/NEJMoa1809944). VITAL's companion fracture study, also 25,871 participants, found no significant reduction in total fractures (HR 0.98) despite marketing claims that vitamin D strongly protects bone health in the general population (https://www.nejm.org/doi/full/10.1056/NEJMoa2202106). A 2023 metaanalys of 17 studies and 38,598 older adults found vitamin D did not significantly reduce fall risk in the general older population (OR 1.01, not significant), showing the fall-prevention benefit is concentrated in specific subgroups, not universal.
Typical dose
800-2000 IU/day (20-50 mcg), with 800-1000 IU/day showing the strongest fracture and fall-prevention signal; higher doses reserved for confirmed deficiency under medical guidance
Säkerhet
Vitamin D3 is generally safe at standard supplemental doses. Excess intake (typically above 4,000 IU/day sustained) can cause hypercalcemia, with symptoms including nausea, weakness, and kidney stones. VITAL and other large trials found no significant increase in serious adverse events at 2000 IU/day. Personer with sarcoidosis, hyperparathyroidism, or a history of kidney stones should use vitamin D supplements cautiously and check blood calcium levels periodically.
Interactions worth flagging
- corticosteroids
- thiazide diuretics
- digoxin
- certain weight-loss drugs that reduce fat absorption (orlistat)
Three recent studies to know
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Vitamin D Supplements and Prevention of Cancer and Cardiovascular DiseaseLäs studie →
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Association between vitamin D supplementation and mortality: systematisk översikt and metaanalysLäs studie →
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Effect of Vitamin D Supplementation on Risk of Fractures and Falls According to Dosage and Serum ConcentrationLäs studie →
Landmark studies
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VITAL Trial 2018
5-year 2000 IU/day showed selective benefits in cancer mortality and cardiovascular events in specific subgroups.
Läs studie →
Found in these produkter (17)
Alla produkter in our catalog that contain Vitamin D3, ranked by our overall score. Ranking is editorial, never paid.
Buying guides and comparisons
Related ingredients
Se alla in Foundational →Molekyler in the same class, plus the actives most often formulated alongside Vitamin D3 in our catalogue.
Frequently asked questions
What is Vitamin D3?
A hormone your skin makes from sunlight. Most people outside the tropics who don't tan or eat a lot of oily fish are deficient, especially in winter.
What dose of Vitamin D3 should I take?
The trial dose in published human studies is 0.05 mg per dag, with a range of 0.025 to 0.125 mg per dag. Always consult a qualified clinician before starting any supplement.
Is Vitamin D3 safe?
Taking without fat = poor absorption. High-dose D3 without K2 can drive calcium into arteries. D2 form (ergocalciferol) is inferior for raising blood levels.
What is the best Vitamin D3 supplement?
We track 17 produkter containing Vitamin D3. The top-ranked product scores 8.6 out of 10 on our composite scale, which evaluates dose, evidence, price, third-party testing, and transparency. See the comparison table above. Scores are editorial judgments, not a scientific standard.
What is the evidence grade for Vitamin D3?
Vitamin D3 has evidence grade A, meaning it is well-supported by replicated human trials. Grade A means replicated human RCTs with hard endpoints. Grade B means human RCTs with biomarker outcomes. Grade C means mixed or small human trials. See our evidence grading methodology.
Data verification
Bevisning grades are reviewed when new human RCTs are published. Product counts update automatically as new produkter are added. Dose ranges reflect published trial data, not brand recommendations. Read how we verify.