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. --NeilN ^{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/enwiki/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)