Talk:Vitamin K2

Comment
Good article, but tbere is too much about Vitamin K1. — Preceding unsigned comment added by 184.147.122.158 (talk) 16:55, 18 April 2014 (UTC)

'Health effects - Bone density' section begins like this: '''It has been suggested that vitamin K2 may play an important role in maintaining healthy levels of bone mineral density (BMD). However, data on the subject is inconclusive - some clinical trials show no improvement of BMD after vitamin K supplementation. First indications came from patients with femoral neck fractures, who demonstrated an extremely low level of circulating vitamin K. The strong association between vitamin K2 deficiency and impaired bone health was later proved by both laboratory and clinical studies.'''

This is confusing. "... data on the subject is inconclusive..." and "... strong association ... later proved...". One of these statements should be changed to remove the inconsistency. Woodlawn bill (talk) 18:47, 19 May 2014 (UTC)

Poor sourcing
Much of this article is sourced to non-WP:MEDRS. A major cleanup is needed. Alexbrn (talk) 12:37, 27 April 2015 (UTC)
 * Bone density: Removed poor reference and aggregated content. Dr Olive (talk) — Preceding undated comment added 21:40, 9 August 2015 (UTC)

use of reference
current statement " MK-4 has been shown to decrease the incidence of fractures up to 87%.[4 " -- Reference 4 demonstrated that MK-4 + vitamin D + calcium versus no treatment (in a nutritionally deficient group) showed a decrease in fractures; not MK-4 as a single agent.Chemistil (talk) 16:43, 16 January 2017 (UTC)

Does reducing arterial calcification actually reduce all-cause mortality?
Does reducing arterial calcification actually reduce risk? Intriguing prevention information but the dangerous plaque in the blood vessels is the unstable form that has not yet calcified. If you reduce the calcification, are you left with unstable plaques? I haven't found the studies, if they exist, showing that reducing existing calcification results in reduced all-cause mortality. If and when that study is done please include it here. — Preceding unsigned comment added by Ocdcntx (talk • contribs) 02:56, 10 June 2015 (UTC)

new age version of K2
site is going to have trouble very non-sci
 * You know it would have gone much better for you if you discussed this calmly, like an adult, instead of throwing a tantrum. And "Creative Commons Attribution-Noncommercial 3.0 Unported License" is not a license compatible with Wikipedia. --Neil N  talk to me 11:32, 30 November 2015 (UTC)

Redundancy
This article needs clean-up. The two sections on dietary intake should be combined. The Japanese dish, natto, is discussed several times, and is of limited application anyway. — Preceding unsigned comment added by 2602:306:CF99:2080:8D5E:AA2B:98B8:FE58 (talk) 12:12, 17 April 2016 (UTC)

I'm going to delete some stuff
Seeing flaws in the article and unanswered questions on the Talk page, I've gone ahead and deleted some stuff. Here's the version before my edits:


 * https://en.wikipedia.org/w/index.php?title=Vitamin_K2&oldid=757063083

In particular, we should improve the bits about about daily requirements. Are there any RDA's? Or are there just "Adequate Intakes"? And do these mention K2 or just K in general? And where are the studies which were used as the basis for these values? (E.g. When the EU's EFSA sets a value it publishes a really cool overview of the existing studies, which is a secondary source, which is the perfect sort of reference for medical topics on WP.) Great floors (talk) 12:33, 14 January 2017 (UTC)


 * Useful documents:
 * EFSA (Draft) opinion on vitamin k
 * It's still just a draft, so I don't know how much we can use it, but at the very least it's a great guide for finding sources we can use. It mentions that there's no RDA, just an AI, and it's for vitamin K1 not K2 due to lack of evidence.  When the EFSA doc is published it will be probably the best reference for this topic, with regard to WP's criteria for references on medical topics.
 * this ConsumerLab page mentions the US IOM didn't set an RDA, only an AI. No mention of whether it's for K1, K2 or unspecified.  Should be easy to find the official source...
 * This 2012 review of then-existing literature contains plenty of things we could use, and it's a good reference (a "secondary source" - the best kind). It says that (as of 2012) there were no studies on k2 and calcification:
 * Overall, the available observational population-based evidence, based on dietary intake measures, suggests menaquinone intake may be more likely to protect against vascular calcification than phylloquinone intake. Yet currently, the only intervention studies have examined the effect of phylloquinone and provide evidence that phylloquinone supplementation is relevant to vascular calcification (60, 66). However, confirmatory studies are needed. Furthermore, because there are no published intervention studies of menaquinone with a measure of vascular calcification as an outcome
 * For "primary sources" (which WP prefers not to rely on, but sometimes it's ok to mention them if there's nothing else), we have
 * A 26-person study showing K2 supplementation as MK-4 having no benefit unless the subject as K2 deficient. 26 subjects is small.
 * The ongoing VitaK-CAC study, which should finish its 24-month trial near the end of 2017, studying MK-7 (I wonder if the 12-month data has been published somewhere).
 * This 2013 study on postmenopausal women, using MK-7, showing bone strength benefits.
 * Great floors (talk) 12:54, 14 January 2017 (UTC)
 * Summary: The high quality references say there's not enough evidence for the possible benefits of k2. In 2017 we'll have the EFSA's document which will just confirm this, and we'll have the VitaK-CAC study which is only a primary source but it'll be the best study available.  Until then, not much. Great floors (talk) 17:01, 14 January 2017 (UTC)

The Agenda of a Pill Pusher
I am so tired of seeing WP:MEDRS tagged on articles. It leads to WP:DELETIONISM, and it is nothing but a guideline. 174.3.179.14 (talk) 01:22, 31 January 2017 (UTC)
 * As a laborer in the arena of food, supplements and health claims, I am a believer in WP:MEDRS. There is way too much weak science in the from of small, poorly designed, poorly interpreted clinical trials, often, collectively, with contradictory results, to rest Wikipedia entries on a foundation of primary research or wimpy reviews.David notMD (talk) 17:03, 11 March 2017 (UTC)

pork, mk-11
don't know where to put this. a study showing US pork supplies, particularly bacon, are high in mk-11 Bacon.

https://www.ncbi.nlm.nih.gov/pubmed/27191033

Although there's no real information on bioavailabilty for this form. — Preceding unsigned comment added by 174.64.73.23 (talk) 19:37, 27 February 2017 (UTC)

Current state of research Nov 2017: ongoing
The VitaK-CAC trial should be finished by now, so I guess the results will be published soon.

Meanwhile, other trials are also ongoing:


 * The effectiveness of vitamin K supplementation to reduce or hold calcification progression is currently subject of investigation in multiple trials (‘iPACK-HD’. Clinicaltrials.gov identifier: NCT01528800, ‘VitaVasK’. ClinicalTrials.gov identifier: NCT01742273, ‘VitaK-CAC trial’. ClinicalTrials.gov identifier: NCT01002157,‘BASIK2’. ClinicalTrials.gov identifier: NCT02917525). (source)

I haven't looked at them to see if they're as good as the VitaK-CAC trial. Just noting them here. Great floors (talk) 17:11, 27 November 2017 (UTC)


 * Does anyone know where to find the results of these? In particular, the Vitak-cac trial should have finished around November 2017 but I can't find anything recent about it. Great floors (talk) 09:30, 28 March 2018 (UTC)

It seems they have pushed the deadline. Tischbeinahe (talk) 08:10, 24 March 2021 (UTC)

MK-4 (45 mg daily) has been approved by the Ministry of Health in Japan since 1995 for the prevention and treatment of osteoporosis.[5]
This amount 45mg seems very high. Is it 45 micrograms? — Preceding unsigned comment added by 31.125.72.166 (talk) 10:37, 8 January 2020 (UTC)


 * 45ucg is more near the number 69.131.216.185 (talk) 11:18, 20 May 2023 (UTC)

Source completely wrong.
Cited source: Jensen GS, Lenninger M, Ero MP, Benson KF (October 2016). "Consumption of nattokinase is associated with reduced blood pressure and von Willebrand factor, a cardiovascular risk marker: results from a randomized, double-blind, placebo-controlled, multicenter North American clinical trial". Integrated Blood Pressure Control. 9: 95–104. doi:10.2147/ibpc.s99553. PMC 5066864. PMID 27785095.

This study is especially about nattokinase WITHOUT Vitamin K2.

K2 having no effect on or even increases calcification

 * This 2019 study claimes MK7 can actually increase „active calcification“ — whatever that is compared to „normal“ calcification. Tischbeinahe (talk) 08:21, 24 March 2021 (UTC)


 * This lab study showed MK4 increases calcification in certain circumstances.


 * Here‘s one showing no effekt in reducing calcification. Tischbeinahe (talk) 08:30, 24 March 2021 (UTC)


 * Another no effect study.

Tischbeinahe (talk) 08:25, 24 March 2021 (UTC)


 * Note that the patients in those trials either had diabetes type 2, chronic kidney problems or undergoing haemodialysis. What seems clear is that more trials are needed before we can know if K2 is beneficial against vascular calficiation and in which cases. There are many medications and supplements that are good and work fine for patients in general, but can increase risks or even be dangerous for small groups of individuals. 2A07:A880:4601:1052:BB82:59DD:C69A:716D (talk) 13:26, 8 January 2022 (UTC)

Anticoagulants - concern content may be applicable to K1 but not K2
Vitamin K1 is well known to affect blood clotting however from what I have read K2 is generally considered not to have any impact on blood clotting. If a specialist in this area reads this can you please check if any content in the section Anticoagulants is actually relevant to K2 please. Specifically concerned about comment "and high vitamin K intake interferes with anticoagulant effects." — Preceding unsigned comment added by 110.175.166.132 (talk) 04:35, 13 October 2021 (UTC)

What absorbption of the various MK-n forms
The food analysis breaks down by various forms : MK-4, MK-5, MK-6, MK-7, MK-8, MK-9, but it's hard to see how much of each will be absorbed or bioavailable. Can we clarify somewhere. - Rod57 (talk) 12:23, 10 January 2022 (UTC)

Table of food analysis
The original ref (Schurgers-2000, given in column header) is vague on methods and exactly what they tested (eg which "hard cheeses" and which "soft cheese") so we could do with other refs. The 2nd ref (Vermeer-2018, used for cheddar & Camembert) is clearer, and also lists many other named cheeses (and eel!) - we could use that ref more. The MK-n concentrations given in the original ref have been sadly converted to % in this article - which makes them hard to verify. - Rod57 (talk) 13:50, 10 January 2022 (UTC)

Vermeer-2018 also says "Remarkably, the menaquinone content of typical Dutch hard cheeses (Gouda, Edam) was relatively high compared to most soft cheeses as produced in Mediterranean countries. This is in contrast to a recent study from the USA [22], in which soft cheeses were found to contain on average about twice as much menaquinones as hard cheeses. This demonstrates the necessity of having national databases for menaquinone content of food." - Rod57 (talk) 13:58, 10 January 2022 (UTC)

Wiki Education assignment: English 216
— Assignment last updated by Noahjp4 (talk) 01:45, 6 October 2023 (UTC)