Low vitamin K2 tracked with calcified arteries, not with a thickened heart
In short
In a cross-sectional study of 189 maintenance hemodialysis patients, serum vitamin K2 below 2.39 nmol/L and age over 65 remained independent risk factors for aortic arch calcification. But neither vitamin K nor Gas6 correlated with left ventricular hypertrophy. The data support one link — vitamin K status and vascular calcification — and not the claim that K2 keeps heart muscle from thickening. It is cross-sectional, so it is not causal, and the population is dialysis patients rather than healthy lifters.
The design is straightforward. Serum vitamin K2 (MK-7) and the vitamin K-dependent protein Gas6 were measured by ELISA in 189 maintenance hemodialysis patients. Left ventricular mass index split them into 110 with hypertrophy and 79 without, while an aortic arch calcification score sorted the same patients into four severity groups (46, 54, 53, and 36 patients). That puts two different kinds of cardiovascular damage — arteries stiffening with calcium and heart muscle thickening — side by side in one cohort.
What turned up, and what did not?
- What turned up — the worse the calcification, the lower the vitamin K2 and the higher the Gas6. After multivariate analysis, age over 65 and vitamin K2 below 2.39 nmol/L stood as independent risk factors for calcification.
- What did not — no correlation between left ventricular hypertrophy and vitamin K or Gas6. A raw comparison showed lower K2 in the hypertrophy group (P<0.05), but that group was also older with higher BNP and creatinine, and the stated conclusion was no association.
- Read the correlations carefully — vitamin K2 correlated strongly and positively with calcium (r=0.822) and negatively with Gas6 (r=-0.339). Those are single-timepoint coefficients; they do not say which way anything runs.
So should you take K2?
This was not a supplementation trial. Nobody was given K2 to see whether calcification slowed; people who already sat low were compared with people who already sat high, at one moment in time. The population also had calcium and phosphorus metabolism far outside the normal range, which makes transfer to a healthy lifter shaky. When a vitamin D product bundled with K2 says it "keeps calcium out of your arteries," this is usually the tier of evidence behind it: an association observed, not an intervention concluded.
Where does that leave a lifter?
Whenever bone and arteries come up, the order is the same: fill the proven stimulus first, and put supplements on top of it. For bone density the lever confirmed in intervention trials is resistance training, and the dose that gets there is set out separately. Supplements have to clear the twin walls of absorption and evidence, and the polyphenol case shows how often that wall comes down. Your training log is the one number in the room marketing cannot move — see what the calculator says instead.
If you take a warfarin-type anticoagulant, or you have kidney disease or are on dialysis, talk to your clinician before changing vitamin K intake. Vitamin K interferes directly with anticoagulation.
Frequently asked questions
Does vitamin K2 prevent vascular calcification?
This study was an observation at one point in time, not an intervention. It confirmed that vitamin K2 below 2.39 nmol/L was an independent risk factor for aortic arch calcification, which is not evidence that supplementing reduces it.
Is left ventricular hypertrophy linked to vitamin K?
Not in this cohort. A raw comparison found lower vitamin K2 in the hypertrophy group, but the stated conclusion was that neither vitamin K nor Gas6 correlated with left ventricular hypertrophy.
What is Gas6?
It is a vitamin K-dependent protein involved in vascular calcification and cell survival signalling. In this study Gas6 ran higher in the more calcified groups and correlated negatively with vitamin K2 (r=-0.339).
Do these numbers apply to healthy people?
Not directly. The participants were maintenance hemodialysis patients, a group with heavily disrupted calcium and phosphorus metabolism. Whether the same threshold holds in the general population is not something this study answers.
What should a lifter do first for bone and artery health?
Resistance training. It has intervention-level evidence for bone density, and supplements are the layer you add on top. The point is not to invert that order of evidence.
Source: PubMed