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Verified by IngredientMD/Thorne/Vitamin D/K2 Liquid
VERIFIED BYingredientMD

Vitamin D/K2 Liquid.

Backed by human trialsThorne, verified Oct 2026Formula verified. Independently reviewed.Independent review. Not commissioned by Thorne.

Vitamin D3 is the lead active here, studied most for filling everyday nutrient gaps. 20 human studies on Vitamin D3 back this formula, each one cited. Who it fits: for everyone, adults.

Full label disclosure
2Active ingredientsWell studiedResearch base30Human studies
Vitamin D/K2 LiquidVerified by IngredientMD
ThorneIngredientMD
The verdict
Backed by human trials
For everyone, adults.
How we verify

The brand submits the formula. We read the supplement facts panel and weigh dose, form and synergy against the clinical evidence. Labs test. IngredientMD verifies. The fee pays for review time, never for the outcome.

The formula
Vitamin D3: Filling everyday nutrient gapsKey driver
Vitamin K2 (MK4): Filling everyday nutrient gapsExtensively studied

How we read this product

Source: Supplement facts
Supplement Facts panel for Vitamin D/K2 Liquid
  1. 01
    We read the label.

    The panel on the left is the one we evaluated, line by line.

  2. 02
    Every active, separately.

    All 2 actives checked against the clinical evidence: dose, form, and what the research actually shows.

  3. 03
    Then the formula as a whole.

    Doses, ratios, and how the ingredients work together. That assessment is the verdict above: "Backed by human trials".

  4. 04
    Earned, not bought.

    The verdict is public and identical whether or not a brand pays. A formula that does not clear the bar gets nothing.

Read by the engine against 2.1 million data points from clinical trials, PubMed and more than a hundred vetted sources. No individual reviewer is named or implied.

The receipts

Well studied
Research base
30
Human studies
1000 iu
Vitamin D3
200 mcg
Vitamin K2 (MK4)
200 mcg per serving clears the studied 45 mcg minimum
Vitamin K2 (MK4), Knapen 2013 + Geleijnse 2004 Rotterdam study

Cross-checked against 1 documented interactions for these actives.

Read the evidenceVitamin D3, the evidence →Vitamin K2 (MK4), the evidence →

Inside the formula

Vitamin D3
20 studies
Filling everyday nutrient gaps
Key driver
Vitamin K2 (MK4)
10 studies
Filling everyday nutrient gaps
Extensively studied
In context

The gap this formula speaks to.

Public health figures the engine matched to this formula's ingredients. Reported by their source, cited and dated, never written by the brand.

The people it speaks toFieldwork 2019

12.3% of US adults

met the fruit intake recommendation and 10.0% the vegetable recommendation in 2019, in the Behavioral Risk Factor Surveillance System across 49 states.

CDC, MMWR, 2022
This formulaNHANES 2017-2018, published 2021

57.6%

During 2017 to 2018, 57.6% of US adults aged 20 and over reported using a dietary supplement in the past 30 days.

CDC National Center for Health Statistics
15 more
The people it speaks to

60.2% of US adults aged 20 and over

took a dietary supplement in the past 30 days, and 38.7% took two or more, in the 2021 to 2023 National Health and Nutrition Examination Survey.

CDC National Center for Health Statistics, 2026
Daily use

59 to 66 days

was the median time it took adults to make a new daily health habit automatic across the studies a 2024 review pooled, with individuals ranging from 4 to 335 days.

Systematic review and meta-analysis, 2024
Vitamin D3

Randomised trial, 2025

Vitamin D3 supplementation changed the inflammatory protein CHI3L1 and oxidative stress markers in adults with a chronic demyelinating condition. These are markers, not clinical outcomes.

Neuropsychopharmacology Reports
Vitamin D3

Meta-analysis, 2024

Across 10 trials in 318 athletes, vitamin D3 raised blood vitamin D by about 14.8 nmol/L and hinted at better muscle strength, though few trials leave that uncertain.

Frontiers in Nutrition
Vitamin K2 (MK4)

Randomised trial, 2024

In a randomised clinical trial, the authors reported fewer nocturnal leg cramp episodes in the vitamin K2 group than in the placebo group over the study period.

JAMA Internal Medicine
Vitamin K2 (MK4)

Systematic review, 2024

A synthesis of vitamin K supplementation trials reports site-dependent effects on bone mineral density and on bone metabolism measures in middle-aged and older adults.

Bone and Joint Research
Vitamin K2 (MK4)

Systematic review, 2025

Pooling trials of vitamin K2 supplementation, the authors report changes in bone turnover biochemical markers in postmenopausal women with reduced bone density.

Frontiers in Endocrinology
Vitamin K2 (MK4)

Systematic review, 2025

A review found vitamin K linked to mood in observational studies, but noted little trial evidence testing it directly.

Medicina
Vitamin D3

Meta-analysis, 2024

Across 20 studies, daily vitamin D3 raised blood vitamin D levels by about 10.4 nmol/L more than the same dose of vitamin D2, roughly 40 percent more.

Advances in Nutrition
Vitamin D3

Meta-analysis, 2014

Across 23 trials of 4,082 adults, vitamin D raised bone mineral density at the femoral neck by about 0.8%, with no measurable change at the spine, hip, or other sites.

Lancet

Population figures from public health data. Context for the category, not a statement about any individual and not a claim about this product.

What this formula earned

Every one of these is a fact the engine could ground.

Each line below was derived from this formula's own record at the time of verification. Nothing here was written by the brand, and nothing can be added that the evidence does not carry.

  • Studied in people20 human studies on Vitamin D3 back this formula, each one cited.
  • A mechanism that is settledHow Vitamin D3 and Vitamin K2 (MK4) work is settled pharmacology.
  • Studied together, not just separatelyVitamin K2 (MK4) and Vitamin D3 have been studied together, not only separately.
  • Recent work on the recordThe most recent study on this record was published in 2026.
  • Why this formatIt is a liquid, so the serving can be adjusted and it suits anyone who would rather not swallow a capsule.
  • The exact form, describedThe label names its forms exactly: Vitamin D3 in a carrier oil, lanolin-derived, Synthetic all-trans menaquinone-4. The record says what each one is and what it suits.
  • Full label disclosureEvery ingredient on this label carries its own declared amount.
  • Where it comes from and how it is madeVitamin D3 is made by more than one route.
  • Positions this formula already qualifies forThis formula already qualifies for positions beyond the one it is sold into, on the evidence it carries.
  • A position nobody is holding yetSome of those positions are ones almost nobody is selling to yet.
What the trials show

What the trials show about timing.

Time-to-effect windows the engine read from the trial record. Each is a window a named study measured, cited and dated, never written by the brand.

  • Vitamin D3about 3 months of daily useBuilds with daily use

    In the trial record, blood vitamin D rises for about 3 months of daily vitamin D3 and then holds at a plateau, near 69 nmol/L at 1,000 IU a day, from a starting level near 41 nmol/L.

    Early

Windows measured in the cited trials. Context for how the active behaves over time, not a statement about any individual and not a claim about this product.

General timing

How each ingredient usually behaves over time.

Two ingredients, from each one's own page.

  • Vitamin D3About six to twelve weeks

    25-hydroxyvitamin D climbs over roughly six to twelve weeks of daily dosing before it plateaus. It's a blood level you watch rather than a feeling.

    Its own page, the plain answer on timing

  • Vitamin K2 (MK4)About four to twelve weeks

    Carboxylation markers move over four to twelve weeks, and the bone studies on this form run six to twenty-four months. Nothing arrives on a daily timescale.

    Its own page, the plain answer on timing

How each ingredient usually behaves over time, from its own page on IngredientMD. General timing for the ingredient, not a measurement of this product.

Chemical form

The same ingredient, carried differently.

What each form is, and where it fits in a formula. Measured findings carry the study that reported them.

  • Cholecalciferol (vitamin D3)

    The animal-sourced form of vitamin D, made in skin under UVB light and produced commercially from lanolin. Fat-soluble, so it travels with dietary fat and is stored in body fat.

    Fits
    Raising and holding vitamin D status, and the form most supplement trials use.
    Trade-off
    Being fat-soluble it accumulates with sustained high dosing, so intakes are set against the tolerable upper level rather than topped up freely.

    In a 12-week double-blind randomised controlled trial in 108 young women in urban Bangalore, most of whom began vitamin D-deficient, daily vitamin D3 at 400, 600 or 800 IU in a fortified wafer raised serum 25-hydroxyvitamin D, parathyroid hormone fell over time, and effects on bone-turnover markers were modest and not dose specific. The 800 IU dose brought 65 percent of participants to sufficiency.

Descriptions of the form itself, read from the cited studies. Not a comparison between products and not a statement about any individual.

Format

Liquid

It is a liquid, so the serving can be adjusted and it suits anyone who would rather not swallow a capsule.

Best forChildren, precise or scaled dosing, and anyone who cannot take solids.

Questions shoppers ask

Is Vitamin D/K2 Liquid independently verified?
Yes. IngredientMD reviewed this formula independently and verified it in Oct 2026. The verdict is earned, not bought: brands can't edit or purchase it.
What's in Vitamin D/K2 Liquid?
Vitamin D/K2 Liquid is built on Vitamin D3, Vitamin K2 (MK4). Each ingredient links to its own evidence page on IngredientMD.
Were ingredient interactions checked?
Yes. The combination was screened against 1 documented interactions for these actives in IngredientMD's interaction database.
Who is IngredientMD?
IngredientMD is an independent supplement-science platform. We analyze ingredients and formulas against clinical research, and we verify products only when they clear our bar. Labs run the tests. We review the results.
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These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. This record is not medical advice. Always consult your healthcare provider before starting any supplement regimen.

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