Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Testing evidence
Evidence status
Testing claimed
Manufacturer statement
Nutricost product page states: “Third-Party Tested †” and “Nutricost products are tested by an independent, accredited lab to help verify that what’s on the label is what’s in the bottle.”
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Testing evidence
Evidence status
Testing claimed
Manufacturer statement
Nutricost product page states: “Third-Party Tested †” and “Nutricost products are tested by an independent, accredited lab to help verify that what’s on the label is what’s in the bottle.”
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Testing evidence
Evidence status
Testing claimed
Manufacturer statement
Carlyle’s own manufacturing page says: “We conduct testing in our microbial lab, examining for purity, potency, and composition, to validate the identity of each of our ingredients.”
Compare the exact K form first, then the labelled K2 amount per day. K1 and D3 are recorded separately, and milligram-scale MK-4 products are not comparable with microgram-scale MK-7. The amount is what the label states, not a dose-adequacy rating. Where directions give a range, the range is shown and daily cost uses the low end (no directions: one unit a day). Read the dose guide ↓
Carlyle’s own manufacturing page says: “We conduct testing in our microbial lab, examining for purity, potency, and composition, to validate the identity of each of our ingredients.”
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Nutricost product page states: “Third-Party Tested †” and “Nutricost products are tested by an independent, accredited lab to help verify that what’s on the label is what’s in the bottle.”
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Micro Ingredients FAQ: "How does Micro Ingredients ensure product safety? We have stringent quality control for our products, and we hire 3rd party lab testers to ensure the quality of our raw materials." Also: "Are your products third-party lab tested? Yes, our products are third-party lab tested for heavy metals and micro-organisms."
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Nutricost product page states: "Third-Party Tested †" and "Nutricost products are tested by an independent, accredited lab to help verify that what’s on the label is what’s in the bottle."
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
NOW product page says: "Made and quality tested in the USA with globally sourced ingredients." NOW's quality page also says it conducts over 31,000 tests each month and partners with outside labs, but I did not find an independently verifiable product-specific COA or certification for this exact product.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Bronson’s Certifications page says: “Every product manufactured by Bronson is put through a rigorous process to ensure purity, potency and integrity… Bronson products consistently comply with the most current regulations to deliver premium supplements verified for quality and safety” and “From raw materials to finished batches, Bronson supplements undergo numerous laboratory tests to ensure quality standards are met.”
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Bronson’s own Certifications page states: “Every product manufactured by Bronson is put through a rigorous process to ensure purity, potency and integrity… Bronson products consistently comply with the most current regulations to deliver premium supplements verified for quality and safety” and “From raw materials to finished batches, Bronson supplements undergo numerous laboratory tests to ensure quality standards are met.”
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
NOW’s product page says: “Made and quality tested in the USA with globally sourced ingredients.” NOW’s quality page also says it performs over 31,000 tests each month and partners with third-party labs for independent verification, but I did not find an independently verifiable COA or certification for this specific MK-7 300 mcg product.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Bronson’s own Certifications page says: “Every product manufactured by Bronson is put through a rigorous process to ensure purity, potency and integrity… Bronson products consistently comply with the most current regulations to deliver premium supplements verified for quality and safety” and “From raw materials to finished batches, Bronson supplements undergo numerous laboratory tests to ensure quality standards are met.” I did not find an independently verifiable COA or a registry entry for this specific Bronson Vitamin K2 100 mcg product; NSF registry checks surfaced other brands/products, not this one.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Amazon listing says the product is 'Laboratory Tested' and Doctor's Best's own product page says 'High quality: the natural vitamin K2 capsules from Doctor's BEST are tested in independent laboratories for quality and purity.' Doctor's Best's 'Natural Vitamin K2 Family' fact sheet also says 'Every batch undergoes thorough testing authenticated by a Certificate of Analysis.'
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Manufacturer site says: "To ensure that all products meet the highest standards, our raw materials are scientifically tested before use, and every formula is tested to confirm its quality." The product page also says Pure Encapsulations is "NSF-GMP registered in the U.S., GMP certified in Canada, and exceeds the standards of the United States Pharmacopeia (USP) for supplement manufacturing."
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Thorne’s product page states: “This product has been third-party tested and certified to verify what's in the package matches what's on the label and to confirm it contains no unsafe levels of contaminants, such as heavy metals, pesticides, and microorganisms.” NSF’s official listing for Thorne under NSF/ANSI Standard 173 confirms Thorne products are officially listed/certified by NSF.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Sports Research product page says "Third Party Tested Certified" and also lists "Third Party Tested" under manufactured-with-care claims for Vitamin K2 as MK7 with Coconut Oil (100 MCG / 60 Softgels and other sizes).
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Solgar product page says “SCIENCE BACKED FORMULAS” and “The Gold Standard,” but I did not find any independent third-party certificate, lab report, or registry entry for this specific vitamin K2 product.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Nature Made’s product page states: “USP has tested and verified ingredients, potency and manufacturing process.” USP’s own verified-products registry lists “Nature Made Vitamin D3 + K2 Softgels” under Nature Made / Softgels / Vitamin.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Life Extension’s own FAQ says: “Does the label accurately list what’s in the bottle? Yes… the ingredients are verified using advanced analytical methods like high performance liquid chromatography and mass spectrometry to ensure every product accurately meets label claims.” It also says Life Extension is “GMP registered with NSF International,” but I did not find an NSF registry page confirming this specific product.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Jarrow’s own product page says: “Raw materials are tested for identity, purity, and potency before production begins. Finished products are tested again. Our in-house analytical labs run full-spectrum analysis so nothing leaves our facility without verification.”
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Manufacturer site states: "To ensure the highest safety and quality, our products undergo rigorous testing for heavy metals and unwanted compounds during production..." and the product image shows a "Certified B Corporation" badge, but I did not find an independently verifiable product-specific COA, independent lab report, or certifying-body registry entry for this Vitamin K2 product.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Seeking Health’s product page says “Third Party Tested,” and its Quality Standards page says “Every ingredient is carefully researched and tested” plus lists “Microbiological Organism Analysis,” “Heavy Metal Analysis,” “Potency Analysis,” and “Residual So…” as part of its facilities/processes. I did not find an independently verifiable COA for this specific product or a registry entry for this specific product.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Nature Made’s product page states: “United States Pharmacopeia (USP) Verified” and “USP has tested and verified ingredients, potency and manufacturing process.” USP’s own Quality Supplements registry lists Nature Made Vitamin D3 + K2 Softgels as a USP Verified product, but I did not find a USP registry entry for this exact Vitamin K2 100 mcg Softgels product.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Life Extension’s own safety page says: “Certificate of Analysis… We are happy to provide a summary of the reports we receive from the contract manufacturers and the independent laboratories that test both our raw materials and final products. We can do this for every supplement…”
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Solaray’s product page says: “This high-quality supplement is produced in our GMP facility certified by NSF featuring ingredients that are triple-tested to meet strict guidelines on potency, purity, and contaminants.” It also says: “TESTED by SuppCo certified. Anonymously purchased and independently tested in ISO 17025 accredited labs—verified to contain exactly what our label claims.”
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Carlyle’s own manufacturing page says: “We conduct testing in our microbial lab, examining for purity, potency, and composition, to validate the identity of each of our ingredients.”
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Nutricost product page states: “Third-Party Tested †” and “Nutricost products are tested by an independent, accredited lab to help verify that what’s on the label is what’s in the bottle.”
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Micro Ingredients FAQ: "How does Micro Ingredients ensure product safety? We have stringent quality control for our products, and we hire 3rd party lab testers to ensure the quality of our raw materials." Also: "Are your products third-party lab tested? Yes, our products are third-party lab tested for heavy metals and micro-organisms."
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Nutricost product page states: "Third-Party Tested †" and "Nutricost products are tested by an independent, accredited lab to help verify that what’s on the label is what’s in the bottle."
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
NOW product page says: "Made and quality tested in the USA with globally sourced ingredients." NOW's quality page also says it conducts over 31,000 tests each month and partners with outside labs, but I did not find an independently verifiable product-specific COA or certification for this exact product.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Bronson’s Certifications page says: “Every product manufactured by Bronson is put through a rigorous process to ensure purity, potency and integrity… Bronson products consistently comply with the most current regulations to deliver premium supplements verified for quality and safety” and “From raw materials to finished batches, Bronson supplements undergo numerous laboratory tests to ensure quality standards are met.”
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Bronson’s own Certifications page states: “Every product manufactured by Bronson is put through a rigorous process to ensure purity, potency and integrity… Bronson products consistently comply with the most current regulations to deliver premium supplements verified for quality and safety” and “From raw materials to finished batches, Bronson supplements undergo numerous laboratory tests to ensure quality standards are met.”
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
NOW’s product page says: “Made and quality tested in the USA with globally sourced ingredients.” NOW’s quality page also says it performs over 31,000 tests each month and partners with third-party labs for independent verification, but I did not find an independently verifiable COA or certification for this specific MK-7 300 mcg product.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Bronson’s own Certifications page says: “Every product manufactured by Bronson is put through a rigorous process to ensure purity, potency and integrity… Bronson products consistently comply with the most current regulations to deliver premium supplements verified for quality and safety” and “From raw materials to finished batches, Bronson supplements undergo numerous laboratory tests to ensure quality standards are met.” I did not find an independently verifiable COA or a registry entry for this specific Bronson Vitamin K2 100 mcg product; NSF registry checks surfaced other brands/products, not this one.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Amazon listing says the product is 'Laboratory Tested' and Doctor's Best's own product page says 'High quality: the natural vitamin K2 capsules from Doctor's BEST are tested in independent laboratories for quality and purity.' Doctor's Best's 'Natural Vitamin K2 Family' fact sheet also says 'Every batch undergoes thorough testing authenticated by a Certificate of Analysis.'
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Manufacturer site says: "To ensure that all products meet the highest standards, our raw materials are scientifically tested before use, and every formula is tested to confirm its quality." The product page also says Pure Encapsulations is "NSF-GMP registered in the U.S., GMP certified in Canada, and exceeds the standards of the United States Pharmacopeia (USP) for supplement manufacturing."
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Thorne’s product page states: “This product has been third-party tested and certified to verify what's in the package matches what's on the label and to confirm it contains no unsafe levels of contaminants, such as heavy metals, pesticides, and microorganisms.” NSF’s official listing for Thorne under NSF/ANSI Standard 173 confirms Thorne products are officially listed/certified by NSF.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Sports Research product page says "Third Party Tested Certified" and also lists "Third Party Tested" under manufactured-with-care claims for Vitamin K2 as MK7 with Coconut Oil (100 MCG / 60 Softgels and other sizes).
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Solgar product page says “SCIENCE BACKED FORMULAS” and “The Gold Standard,” but I did not find any independent third-party certificate, lab report, or registry entry for this specific vitamin K2 product.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Nature Made’s product page states: “USP has tested and verified ingredients, potency and manufacturing process.” USP’s own verified-products registry lists “Nature Made Vitamin D3 + K2 Softgels” under Nature Made / Softgels / Vitamin.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Life Extension’s own FAQ says: “Does the label accurately list what’s in the bottle? Yes… the ingredients are verified using advanced analytical methods like high performance liquid chromatography and mass spectrometry to ensure every product accurately meets label claims.” It also says Life Extension is “GMP registered with NSF International,” but I did not find an NSF registry page confirming this specific product.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Jarrow’s own product page says: “Raw materials are tested for identity, purity, and potency before production begins. Finished products are tested again. Our in-house analytical labs run full-spectrum analysis so nothing leaves our facility without verification.”
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Vitamin K form
MK-7 + MK-4Softgel
Daily dose
600 mcg
Testing evidence
Evidence status
Testing claimed
Manufacturer statement
Manufacturer site states: "To ensure the highest safety and quality, our products undergo rigorous testing for heavy metals and unwanted compounds during production..." and the product image shows a "Certified B Corporation" badge, but I did not find an independently verifiable product-specific COA, independent lab report, or certifying-body registry entry for this Vitamin K2 product.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Seeking Health’s product page says “Third Party Tested,” and its Quality Standards page says “Every ingredient is carefully researched and tested” plus lists “Microbiological Organism Analysis,” “Heavy Metal Analysis,” “Potency Analysis,” and “Residual So…” as part of its facilities/processes. I did not find an independently verifiable COA for this specific product or a registry entry for this specific product.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Nature Made’s product page states: “United States Pharmacopeia (USP) Verified” and “USP has tested and verified ingredients, potency and manufacturing process.” USP’s own Quality Supplements registry lists Nature Made Vitamin D3 + K2 Softgels as a USP Verified product, but I did not find a USP registry entry for this exact Vitamin K2 100 mcg Softgels product.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Life Extension’s own safety page says: “Certificate of Analysis… We are happy to provide a summary of the reports we receive from the contract manufacturers and the independent laboratories that test both our raw materials and final products. We can do this for every supplement…”
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Solaray’s product page says: “This high-quality supplement is produced in our GMP facility certified by NSF featuring ingredients that are triple-tested to meet strict guidelines on potency, purity, and contaminants.” It also says: “TESTED by SuppCo certified. Anonymously purchased and independently tested in ISO 17025 accredited labs—verified to contain exactly what our label claims.”
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
One-time purchase prices; delivery and conditional discounts excluded. Daily cost uses the recorded label serving. Comparison amounts are not personal dose recommendations. Unknown Prime eligibility is not treated as confirmed.
Vitamin K2 forms and labels explained
Compare Vitamin K2 by exact form and daily amount, then check K1, D3 and quality claims separately. Total-vitamin-K Daily Values are useful label context but not a K2 dose target.
MK-7
Menaquinone-7
Typical label unit
mcg
Evidence
Form-specific
Longer persistence and form-specific trials do not make MK-7 a universal winner over MK-4.
MK-4
Menaquinone-4 / menatetrenone
Study units
mcg to mg
Important
45 mg = 45,000 mcg
Therapeutic 45 mg MK-4 evidence must not be transferred to 100 mcg retail MK-4 products.
K1 phylloquinone
Vitamin K1, not K2
Main context
Total vitamin K guidance
Keep separate
K1 and K2 amounts
Regional vitamin K intake references apply to total vitamin K rather than a K2-only requirement.
D3 K2 combination
Two separate vitamins
Record
K2 mcg/day
Also record
D3 mcg and IU/day
A combination label does not prove K2 is required with every vitamin D supplement or that it protects against excessive vitamin D.
All trans MK-7
MK-7 geometric-isomer claim
Useful evidence
Isomer-specific assay
Not enough
Marketing claim alone
All-trans quality can be analytically assessed, but this is not itself proof of superior clinical outcomes.
Vitamin K2 dose: separate K2 from total vitamin K guidance
NIH sets Adequate Intakes for total vitamin K at 120 mcg/day for adult men and 90 mcg/day for adult women, while FDA's label Daily Value is 120 mcg. [1][2] These are not MK-7-specific or K2-specific targets.
Human K2 studies use very different form-specific amounts: 180 or 375 mcg/day MK-7 in long-term bone trials, 360 mcg/day MK-7 in vascular trials, 1.5 mg/day MK-4 in one bone study and 45 mg/day MK-4 in pharmacological osteoporosis treatment. [4][5][6][7][10]
No vitamin K UL is established by the Food and Nutrition Board. [1] Absence of a UL should not be turned into a recommendation for high-dose self-supplementation.
What the Vitamin K2 evidence shows
Bone evidence is mixed. One 180 mcg/day MK-7 trial found less decline in selected bone measures, whereas a 375 mcg/day trial with calcium and D3 improved osteocalcin carboxylation but did not improve BMD or microarchitecture. [4][5] Meta-analyses pool different K2 forms and therapeutic contexts, so their results do not establish a universal consumer dose. [8]
Cardiovascular evidence was inconsistent in earlier controlled-trial reviews. [9] A 2026 randomized trial found slower coronary artery calcium progression with MK-7 360 mcg/day for two years in symptomatic CAD, but whether this improves clinical cardiovascular outcomes remains unknown. [10]
Vitamin K2 evidence by research question
Evidence by goal
Goal
Evidence strength
What was assessed
Typical study context
Main limitation
Postmenopausal bone loss
Mixed MK-7 evidence
MK-7 180 or 375 mcg/day
Two three-year randomized trials in postmenopausal women produced different BMD outcomes.
Different populations and co-interventions; no universal effective MK-7 dose.
Osteoporosis treatment
Therapeutic MK-4 evidence
MK-4 45 mg/day
Japanese studies used 45,000 mcg/day in osteoporosis treatment.
Pharmacological context; cannot be transferred to 100 mcg retail MK-4.
Coronary artery calcification
Promising recent imaging evidence
MK-7 360 mcg/day
2026 randomized trial in symptomatic CAD followed patients for two years.
Surrogate imaging outcome and disease population; clinical-event benefit remains unknown.
Chromatographic and laboratory studies can distinguish isomers and biological activity.
Not a clinical trial proving an all-trans product produces superior health outcomes.
Read the full evidence-by-goal detail
Bone health
K2 can change vitamin-K-dependent bone proteins, but trial outcomes vary by form and population. [4][5] Pharmacological MK-4 at 45 mg/day should not be treated as evidence that ordinary microgram-dose retail MK-4 works the same way. [7]
Vascular calcification
A 2020 systematic review found no consistent benefit across controlled trials, while the 2026 VitaK-CAC trial found slower CAC progression with MK-7 in symptomatic CAD. [9][10] The latter is an imaging outcome, not proof of fewer heart attacks or deaths.
General supplementation
NIH vitamin K recommendations refer to total vitamin K intake. They do not establish that healthy adults universally need a separate K2 supplement. [1]
When to take Vitamin K2
No universal morning-versus-evening advantage was identified. Follow the Supplement Facts directions. Vitamin K is fat-soluble, but product timing instructions should not be turned into a K2 efficacy ranking.
Vitamin K2 safety and anticoagulant cautions
Who should be cautious?If any of the following apply to you, speak to a healthcare professional before taking Vitamin K2 - see the full detail below for why.
People taking warfarin or similar vitamin-K-antagonist anticoagulants
People whose vitamin K intake is being intentionally stabilised for anticoagulation management
People considering milligram-scale MK-4 treatment without clinical supervision
People using high-dose D3 + K2 products who need vitamin D assessed separately
NIH states that vitamin K can have a serious and potentially dangerous interaction with warfarin and similar anticoagulants. People taking them need consistent vitamin K intake and clinician-managed supplement changes. [1]
The Food and Nutrition Board has not established a vitamin K UL because of low observed toxicity potential. [1] That does not make pharmacological MK-4 dosing appropriate for unsupervised use.
Vitamin K2 with D3 and other nutrients
K2 is frequently sold with vitamin D3. One current US example provides 90 mcg MK-7 with 125 mcg (5,000 IU) D3 in one chewable. [16] The D3 amount must be assessed independently.
No NIH source checked establishes a universal requirement that everyone taking ordinary vitamin D also needs K2, and K2 should not be presented as protection from excessive vitamin D. [18]
Who might consider Vitamin K2?
Adults looking at K2 for bone or vascular research questions should match the exact form and population rather than using the largest dose or a total-vitamin-K Daily Value as a shortcut. MK-7 and MK-4 studies are not interchangeable.
People using warfarin or a similar vitamin-K antagonist should treat any vitamin K supplement change as a clinician-managed decision. [1]
How to compare Vitamin K2 testing evidence
Useful K2 testing verifies form identity and potency in the finished product. For MK-7, all-trans and cis/trans isomer proportions can also be measured. Analytical research has shown that method choice and formulation can affect MK-7 quantification. [12] Laboratory evidence also suggests trans and cis MK-7 differ in carboxylative activity. [13]
FDA cGMP controls concern identity, purity, strength, composition and contaminants, but they are not independent finished-batch clinical or all-trans verification. [17]
Testing evidence in this comparison
A testing claim is not the same as a verified report. No public evidence located does not mean a product has not been tested.
Testing review pending0
Recognised certification1
Verified independent evidence0
Manufacturer COA0
Testing claimed22
No public evidence located3
What does vitamin k2 cost?
Current US comparison set, based on the daily serving shown on each label.
$0.06Lowest daily cost
$0.22Median daily cost
$0.80Highest daily cost
Your questions, answered
Is MK-7 better than MK-4?
No universal winner is established. MK-7 and MK-4 have different pharmacokinetics and study histories. MK-7 trials generally use micrograms, whereas osteoporosis-treatment MK-4 studies often use 45 mg/day. [4][7]
What is the Daily Value for Vitamin K2?
FDA's 120 mcg Daily Value is for total vitamin K, not specifically K2 or MK-7. [2] Current K2-specific labels may therefore separately state that a Daily Value for that individual K2 ingredient is not established.
Do I need Vitamin K2 with Vitamin D3?
No NIH source checked established a universal requirement to pair K2 with ordinary vitamin D supplementation. Vitamin D has its own intake and safety guidance. [18]
Can I take K2 with warfarin?
Vitamin K can have a serious interaction with warfarin. NIH advises maintaining consistent vitamin K intake and managing changes with a healthcare provider. [1]
What does all-trans MK-7 mean?
MK-7 can occur in different geometric isomers. Analytical methods can quantify all-trans and cis/trans forms, and laboratory work suggests activity differs. [12][13] This is a quality/form issue, not automatic proof of better clinical outcomes.
