To reiterate my main points:
AFAIK, the preference for mk-4 that myself, michael rae, and everyone else on planet earth prefers is based on human studies, not "wacky evidence".
Please do not involve any appeals to authority, because a. authority does not matter over evidence and b. you are wrong as the "authorities" tend to disagree and have differing opinions themselves and do not genuinely
favour MK-4 over all the other vit K vitamers. The
non-exclusive use of MK-4 among CRONies can be largely attributed to its potential, unique benefits on bone. It's not like K1 or long-chain vitamers are ignored and not used.
EDIT: as much as dislike to argue based on authority. There "could" be a reason why MK-4 is always studied at mega- and not dietary-doses and why on
clinicaltrials.gov you can only find MK-7/k1 studies that are of relevance to LE (CVD, cancer)
maybe supplementing MK-4 is an insurance policy, if you are consistently consuming chicken. but i'm closer to a vegan+fish diet (low dairy, low meat). so in my case, MK-4 is required. and given that most data seems to indicate MK-4 does everything MK-7 and other forms do... are longer chains necessary? i don't know, but a little bit of cheese as an insurance policy is probably fine.
whether or not the MK-7/8/9/10 will convert in vivo, who knows. getting a bit of both, with focus on mk-4 seems ideal to me.
I don't want to discourage your opinion, but I would again like to emphasise that the evidence from
randomised controlled trials (as of now) only supports phylloquinone for LE related outcomes (CVD /-surrogates, cancer in some cases); key examples being:
Vitamin K supplementation and progression of coronary artery calcium in older men and women. Shea et al.
Beneficial effects of vitamins D and K on the elastic properties of the vessel wall in postmenopausal women: a follow-up study. Braam et al.
Vitamin K supplementation in postmenopausal women with osteopenia (ECKO trial): a randomized controlled trial. Cheung et al. (I did not manage to more than skim this pretty "famous" paper yet)
And the
epidemiology almost always looks at a mix of K2 vitamers, perhaps even favouring long-chain vitamers in a few cases (CVD /-surrogates, cancer):
They all show pretty much the same; Rotterdam study, cross-sectional/prospective analyses of EPIC. To quote the most recent analysis from EPIC-Heidelberg, hot off the presses:
"Both MK-4 and the sum of MK-5 to MK-9 were significantly inversely associated with total cancer mortality when modeled separately (data not
shown)."
Dietary vitamin K intake in relation to cancer incidence and mortality: results from the Heidelberg cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC-Heidelberg). Nimptsch et al.
In the Rotterdam cohort long-chain menaquinones were more abundant and even based solely on this fact are more likely to drive the association (but see also below):
Dietary intake of menaquinone is associated with a reduced risk of coronary heart disease: the Rotterdam Study. Geleijnse et al.
In this study (though, it suffers from a small sample size and cross-sectional design) long-chain vitamers were solely responsbile for beneficial associations:
A high menaquinone intake reduces the incidence of coronary heart disease. Gast et al.
etc, etc.
I do not want to go over the
mechanistic, animal and in vitro data, but there is evidence to suggest that long-chain vitamers are (sometimes considerably) more effective at gamma-carboxylation (still the accepted main mechanism of action of vitamin K derivatives) than either short-chain vitamers and/or K1. In the case of K1 there is very strong evidence for the superiority of MK-7 and we should keep in mind that it was K1 showing the outstanding results in RCTs while MK-7 studies are ongoing (unfortunately no MK-4 studies to my knowledge, hence there will be no conclusive, esp. no head to head, evidence for a long time).
Still no credible evidence shows that MK-4 is superior other than for HCC and osteoporsis (!) Indeed, MK-4 may be similarly effective as MK-7, but I think doubts are justified that it isn't so mcg per mcg and that one would need unnatural, non-dietary mega-doses of MK-4. But if you go with mega-doses e.g. used to treat osteoporosis, you completely break with the "paleo ideology" and the idea of replicating the epidemiology and human biology anyway. If you take low MK-4 doses you could be taking an ineffective dose and I would strongly recommend to add (consume) either MK-7 or high dose K1. Hence I think that either and especially a vitamin K mix is a good "insurance policy".
There is all the reason in the world to favour K1 and MK-7 if osteoporosis is not a concern to you.
Edited by kismet, 28 April 2010 - 03:37 PM.