Cheap, safe, and correcting a deficiency you probably have.
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.
Vitamin D3 (Vitamin D3 (Cholecalciferol)) is a foundational with evidence grade A, meaning it is well-supported by replicated human trials. We track 17 products containing Vitamin D3. Typical doses range from 0.01 to 0.125 mg per serving. The top-ranked product scores 9.4 out of 10 on our composite scale (dose, evidence, price, testing, transparency). Prices range up to $55.95 per month.
| Product | Brand | Dose | Price/mo | 3rd-party tested | Score |
|---|---|---|---|---|---|
| Vitamin D3 5000 | Nordic Naturals | 0.125 mg | $24.95 | Yes | 9.4 |
| UnoCardio 1000 + Vitamin D | WHC (UnoCardio) | 0.025 mg | $49.95 | Yes | 9.3 |
| Ultimate Omega-D3 2X | Nordic Naturals | 0.025 mg | $55.95 | Yes | 9.1 |
| Vitamin D3+K2 | Nordic Naturals | 0.05 mg | $19.95 | Yes | 8.9 |
| Jarrow Formulas Vitamin D3, 5000 IU (125 mcg) | Jarrow Formulas | 0.125 mg | $12.74 | No | 8.5 |
Scores are editorial judgments, not a scientific standard. See how we score.
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.
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.
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.
Cholecalciferol, converted to 25-OH-D in liver, 1,25-(OH)₂-D in kidney. Nuclear receptor ligand.
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.
~15 days (25-OH-D storage form).
Taking without fat = poor absorption. High-dose D3 without K2 can drive calcium into arteries. D2 form (ergocalciferol) is inferior for raising blood levels.
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/
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.
Regulatory events, evidence grade changes, and key research milestones for Vitamin D3, most recent first. Studies link to the paper; regulatory entries name and link the responsible authority.
Verified 2026-08-02. We update this section as new peer-reviewed trials land.
Vitamin D's best-supported human benefit is a modest reduction in cancer death, not cancer incidence. A 2019 meta-analysis (VITAL and prior trials) and a 2019 BMJ meta-analysis 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 meta-analysis 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 meta-analysis 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/).
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 meta-analysis 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.
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
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. People with sarcoidosis, hyperparathyroidism, or a history of kidney stones should use vitamin D supplements cautiously and check blood calcium levels periodically.
5-year 2000 IU/day showed selective benefits in cancer mortality and cardiovascular events in specific subgroups.
Read study →All products in our catalog that contain Vitamin D3, ranked by our overall score. Ranking is editorial, never paid.
Nordic NaturalsStatus as recorded in the catalog from brand materials; not independently verified by NO1GEVITY.
Editorial score, not proof that this product works. Research-dose calculations are not dosing advice.
WHC (UnoCardio)Undisclosed amounts noted
Status as recorded in the catalog from brand materials; not independently verified by NO1GEVITY.
Editorial score, not proof that this product works. Research-dose calculations are not dosing advice.
Nordic NaturalsStatus as recorded in the catalog from brand materials; not independently verified by NO1GEVITY.
Editorial score, not proof that this product works. Research-dose calculations are not dosing advice.
Nordic NaturalsStatus as recorded in the catalog from brand materials; not independently verified by NO1GEVITY.
Editorial score, not proof that this product works. Research-dose calculations are not dosing advice.
Jarrow FormulasStatus as recorded in the catalog from brand materials; not independently verified by NO1GEVITY.
Editorial score, not proof that this product works. Research-dose calculations are not dosing advice.
Thorne HealthTechMulti-ingredient bundle
Status as recorded in the catalog from brand materials; not independently verified by NO1GEVITY.
Editorial score, not proof that this product works. Research-dose calculations are not dosing advice.
AG1 (Athletic Greens)Multi-ingredient bundle
Status as recorded in the catalog from brand materials; not independently verified by NO1GEVITY.
Editorial score, not proof that this product works. Research-dose calculations are not dosing advice.
Multi-ingredient bundle
Status as recorded in the catalog from brand materials; not independently verified by NO1GEVITY.
Editorial score, not proof that this product works. Research-dose calculations are not dosing advice.
AgeMateMulti-ingredient bundle
Status as recorded in the catalog from brand materials; not independently verified by NO1GEVITY.
Editorial score, not proof that this product works. Research-dose calculations are not dosing advice.
WonderfeelMulti-ingredient bundle
Status as recorded in the catalog from brand materials; not independently verified by NO1GEVITY.
Editorial score, not proof that this product works. Research-dose calculations are not dosing advice.
Multi-ingredient bundle
Status as recorded in the catalog from brand materials; not independently verified by NO1GEVITY.
Editorial score, not proof that this product works. Research-dose calculations are not dosing advice.
Thorne HealthTechMulti-ingredient bundle
Status as recorded in the catalog from brand materials; not independently verified by NO1GEVITY.
Editorial score, not proof that this product works. Research-dose calculations are not dosing advice.
Seed HealthMulti-ingredient bundle
Status as recorded in the catalog from brand materials; not independently verified by NO1GEVITY.
Editorial score, not proof that this product works. Research-dose calculations are not dosing advice.
Aidan ProductsMulti-ingredient bundle
Status as recorded in the catalog from brand materials; not independently verified by NO1GEVITY.
Editorial score, not proof that this product works. Research-dose calculations are not dosing advice.
Elemental vs compound: check label
Status as recorded in the catalog from brand materials; not independently verified by NO1GEVITY.
Editorial score, not proof that this product works. Research-dose calculations are not dosing advice.
Elysium HealthMulti-ingredient bundle
Status as recorded in the catalog from brand materials; not independently verified by NO1GEVITY.
Editorial score, not proof that this product works. Research-dose calculations are not dosing advice.
Seed HealthCFU not stored
Status as recorded in the catalog from brand materials; not independently verified by NO1GEVITY.
Editorial score, not proof that this product works. Research-dose calculations are not dosing advice.
Molecules in the same class, plus the actives most often formulated alongside Vitamin D3 in our catalogue.
See Vitamin D3 in context: the mechanism it acts through, the biomarker it moves, the products that dose it, and the trials that tested it.
View Vitamin D3 on the Longevity Map →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.
The trial dose in published human studies is 0.05 mg per day, with a range of 0.025 to 0.125 mg per day. Always consult a qualified clinician before starting any supplement.
UL is 100 mcg/day (4,000 IU/day; equivalent to 0.1 mg) for adults. Toxicity causes hypercalcemia and hypercalciuria; extremely high serum levels can lead to kidney failure and arrhythmias.
We track 17 products containing Vitamin D3. The top-ranked product scores 9.4 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.
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.
Evidence grades are reviewed when new human RCTs are published. Product counts update automatically as new products are added. Dose ranges reflect published trial data, not brand recommendations. Read how we verify.
Rosita
IM8
Vital Proteins