Vitamin K2

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Vitamin K2

Postby schermel » Fri Nov 21, 2014 9:23 am

From what I've read: Necessary for good cardiovascular health. K-1 from leafy greens does not convert very well to K-2. Only natto is a non-meat source.

What's your take on this? Do we need to supplement? Or eat natto (which I hear does not taste very good)? Thanks.
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Re: Vitamin K2

Postby JeffN » Sun Nov 23, 2014 9:28 am

Humans beings are capable of synthesizing adequate amounts of it.

Of course, one must live and eat healthy.

In Health
Jeff

The contribution of vitamin K2 (menaquinones) produced by the intestinal microflora to human nutritional requirements for vitamin K. Am J Gastroenterol. 1994 Jun;89(6):915-23.

http://www.ncbi.nlm.nih.gov/pubmed/8198105

Abstract

BACKGROUND: Coagulopathy manifest by elevation of the prothrombin time (PT) in patients receiving broad spectrum antimicrobials indirectly suggests a role for intestinal microflora synthesized menaquinone (MK) in the maintenance of normal coagulation. Nonetheless, no direct evidence is available to support this contention.

OBJECTIVE: Our objective was therefore to provide evidence that bacterially produced MK may be absorbed by the distal small bowel of humans.

METHODS:Using a cell harvester, Staphylococcus aureus (ATCC 29213) was grown in 12-L batches, harvested, and extracted by high performance liquid chromatography (HPLC) to obtain 8 mg of pure MK. Four normal volunteers were placed on a diet severely restricted in vitamin K1 (median 32-40 U/day), and were given warfarin to maintain an International Normalized Ratio of approximately 2.0. On the 10th day of warfarin administration, naso-ileal intubation was performed and 1.5 mg of MK was delivered into the ileum. PT, factor VII, II and serum vitamin K1 levels were monitored throughout the study.

RESULTS:Mean serum vitamin K1 levels were reduced to 30% of the pre-diet value at the time of MK administration. Within 24 h of ileal MK administration, there was a significant (p < 0.05) increase in the factor VII level of 0.28 +/- 0.10 U/ml (mean +/- SEM) and a significant decrease of 2.5 (+/- 0.1) s in the PT, whereas in the control phase (during which no MK was administered), there were no significant changes in the PT or factor VII at corresponding time intervals.

CONCLUSION:These data provide direct evidence for the absorption of vitamin K2 from the distal small bowel, supporting a definite role for bacterially synthesized vitamin K2 in contributing to the human nutritional requirements of this vitamin.


The production of menaquinones (vitamin K2) by intestinal bacteria and their role in maintaining coagulation homeostasis.
Prog Food Nutr Sci. 1992 Oct-Dec;16(4):307-43.
Conly JM1, Stein K.

http://www.ncbi.nlm.nih.gov/pubmed/1492156

Abstract

Vitamin K is an essential cofactor necessary for the production of clotting factors II, VII, IX, and X in humans and has recently been found to be an essential factor for many other proteins in the body. There are two sources of this essential vitamin, including vitamin K1, or phylloquinone which is primarily found in green leafy vegetables and vitamin K2 or menaquinone which is synthesized by certain intestinal bacteria. The precise contribution of the bacterially synthesized menaquinone to overall vitamin K requirements in man is unknown. This paper reviews the available literature regarding the production and liberation of menaquinones from bacteria, the animal experiments which have been done to examine the absorption of menaquinones and the indirect and direct evidence in humans regarding utilization of menaquinones. The preponderance of the evidence suggests that bacterially synthesized menaquinones, particularly in the ileum can and do play a significant role in contributing to vitamin K requirements in humans to prevent clinically significant coagulopathy, especially during periods of episodic dietary lack of the vitamin.


The contribution of vitamin K2 (menaquinones) produced by the intestinal microflora to human nutritional requirements for vitamin K.
Am J Gastroenterol. 1994 Jun;89(6):915-23.

Abstract

BACKGROUND: Coagulopathy manifest by elevation of the prothrombin time (PT) in patients receiving broad spectrum antimicrobials indirectly suggests a role for intestinal microflora synthesized menaquinone (MK) in the maintenance of normal coagulation. Nonetheless, no direct evidence is available to support this contention.

OBJECTIVE: Our objective was therefore to provide evidence that bacterially produced MK may be absorbed by the distal small bowel of humans.

METHODS: Using a cell harvester, Staphylococcus aureus (ATCC 29213) was grown in 12-L batches, harvested, and extracted by high performance liquid chromatography (HPLC) to obtain 8 mg of pure MK. Four normal volunteers were placed on a diet severely restricted in vitamin K1 (median 32-40 U/day), and were given warfarin to maintain an International Normalized Ratio of approximately 2.0. On the 10th day of warfarin administration, naso-ileal intubation was performed and 1.5 mg of MK was delivered into the ileum. PT, factor VII, II and serum vitamin K1 levels were monitored throughout the study.
RESULTS:
Mean serum vitamin K1 levels were reduced to 30% of the pre-diet value at the time of MK administration. Within 24 h of ileal MK administration, there was a significant (p < 0.05) increase in the factor VII level of 0.28 +/- 0.10 U/ml (mean +/- SEM) and a significant decrease of 2.5 (+/- 0.1) s in the PT, whereas in the control phase (during which no MK was administered), there were no significant changes in the PT or factor VII at corresponding time intervals.

CONCLUSION: These data provide direct evidence for the absorption of vitamin K2 from the distal small bowel, supporting a definite role for bacterially synthesized vitamin K2 in contributing to the human nutritional requirements of this vitamin.
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Re: Vitamin K2

Postby schermel » Sun Nov 23, 2014 11:30 am

Good news! I did try some natto. It wasn't as bad as I thought, but not great. Just finished some steamed potatoes and brussel sprouts! YUM! Thanks very much.
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Re: Vitamin K2

Postby JeffN » Wed May 27, 2020 12:03 pm

The effects of vitamin K-rich green leafy vegetables on bone metabolism: A 4-week randomised controlled trial in middle-aged and older individuals. Bone Rep. 2020 Apr 26;12:100274.
doi: 10.1016/j.bonr.2020.100274.
eCollection 2020 Jun.PMID: 32455149 Free PMC article.

Abstract

Background: High vegetable intake is associated with beneficial effects on bone. However, the mechanisms remain uncertain. Green leafy vegetables are a rich source of vitamin K1, which is known to have large effects on osteoblasts and osteocalcin (OC) metabolism.

Objective: To examine the effects of consumption of two to three extra serves of green leafy vegetables daily on bone metabolism.

Methods: Thirty individuals (mean age 61.8 ± 9.9 years, 67% male) completed three experimental phases in a randomised controlled crossover design, each lasting four weeks, with a washout period of four weeks between phases (clinical trial registration: ACTRN12615000194561). The three experimental phases were: (i) increased dietary vitamin K1 by consuming green leafy vegetables (H-K; ~200 g/d containing 164.3 [99.5-384.7] μg/d of vitamin K1); (ii) low vitamin K1 by consuming vitamin K1-poor vegetables (L-K; ~200 g/d containing 9.4 [7.7-11.6] μg/d of vitamin K1); and (iii) control (CON) where participants consumed an energy-matched non-vegetable control. OC forms, total OC (tOC), carboxylated OC (cOC) and undercarboxylated OC (ucOC), were measured in serum pre- and post-intervention for each experimental phase using a sandwich-electrochemiluminescence immunoassay.
Results: Pre-intervention tOC, ucOC and ucOC:tOC levels were similar between phases (P > .05). Following H-K, but not L-K, tOC, ucOC and ucOC:tOC levels were significantly lower compared to pre-intervention levels (P ≤ .001) and compared to CON (~14%, 31% and 19%, respectively, all P < .05), while cOC remained unchanged.

Conclusions: In middle-aged healthy men and women, an easily achieved increase in dietary intake of vitamin K1-rich green leafy vegetables substantially reduces serum tOC and ucOC suggesting increased entry of OC into bone matrix, where it may improve the material property of bone. In conjunction with previous epidemiological and randomised controlled trial data, these findings suggest that interventions to increase vegetable intake over extended periods should include bone end points including fracture risk.
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Re: Vitamin K2

Postby JeffN » Sun Jul 26, 2020 11:36 am

”In contrast to our hypothesis, active vascular calcification on 18F-NaF PET scan tended to increase after MK-7 supplementation compared with placebo during 6-mo intervention. In addition, no effect of MK-7 supplementation on CT calcification mass was found. Therefore, this study does not support that MK-7 supplementation inhibits vascular calcification.“

The effect of menaquinone-7 supplementation on vascular calcification in patients with diabetes: a randomized, double-blind, placebo-controlled trial

ABSTRACT

Background: Vitamin K occurs in the diet as phylloquinone and menaquinones. Observational studies have shown that both phylloquinone and menaquinone intake might reduce cardiovascular disease (CVD) risk. However, the effect of vitamin K on vascular calcification is unknown.

Objectives: The aim of this study was to assess if menaquinone sup,plementation, compared to placebo, decreases vascular calcification in people with type 2 diabetes and known CVD.

Methods: In this double-blind, randomized, placebo-controlled trial, we randomly assigned men and women with type 2 diabetes and CVD to 360 μg/d menaquinone-7 (MK-7) or placebo for 6 mo. Femoral arterial calcification at baseline and 6 mo was measured with 18sodium fluoride positron emission tomography (18F-NaF PET) scans as target-to-background ratios (TBRs), a promising technique to detect active calcification. Calcification mass on conventional computed tomography (CT) scan was measured as secondary outcome. Dephosphorylated–uncarboxylated matrix Gla protein (dp-ucMGP) concentrations were measured to assess compliance. Linear regression analyses were performed with either TBR or CT calcification at follow-up as the dependent variable, and treatment and baseline TBR or CT calcification as independent variables.

Results: We randomly assigned 35 patients to the MK-7 group (33 completed follow-up) and 33 to the placebo group (27 completed follow-up). After the 6-mo intervention, TBR tended to increase in the MK-7 group compared with placebo (0.25; 95% CI: −0.02, 0.51; P = 0.06), although this was not significant. Log-transformed CT calcification mass did not increase in the intervention group compared with placebo (0.50; 95% CI: −0.23, 1.36; P = 0.18). MK- 7 supplementation significantly reduced dp-ucMGP compared with placebo (−205.6 pmol/L; 95% CI: −255.8, −155.3 pmol/L). No adverse events were reporteD

Conclusion: MK-7 supplementation tended to increase active calcification measured with 18F-NaF PET activity compared with placebo, but no effect was found on conventional CT. Additional research investigating the interpretation of 18F-NaF PET activity is necessary. This trial was registered at clinicaltrials.gov as NCT02839044. Am J Clin Nutr 2019;110:883–890.
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