Vitamin K for Healthy Bones & a Lean Physique: Rat Study Finds Phylloquinone (K1) & Menaquinone (K2) Ward off Fat Gain and Cut Triglycerides by Half

Until not too long ago, scientists thought vitamin D was all about bone. Every follower of this blog knows that this is a way too narrow perspective on what turned out to be more of a hormone than a vitamin. A recent study (Sogabe. 2011) on the effects of vitamin K supplementation in mice does now suggest that vitamin D's "cofactors" phylloquinone (PK, vitamin K1) and menaquinone-4 (MK-4, vitamin K2) have been similarly mistaken.

Figure 1: Weight of visceral fat pad in g after 85 days of  phylloquinone (PK, vitamin K1) or menaquinone-4 (MK-4, vitamin K2) supplementation (Sogabe. 2011)

Japanese scientists, who wanted to investigate the effect of 85 days of vitamin K supplementation (PK: 600 mg/kg; MK-4: 600 mg/kg) on bone development in mice, were surprised to find that vitamin K did not only improve bone mass and structure, but that...

the addition of PK or MK-4 significantly decreased the total fat accumulation (p < 0.01 and p < 0.05, respectively), and serum triglycerides were reduced by 48% in the PK group and 29% in the MK group compared with the control.

This is an interesting result, which is not related to increases in growth hormone release, as one might expect in view of the bone-building effects of vitamin K. The scientists speculate: "The effect of vitamin K on fat mass could be mediated through adiponectin regulation which itself has been found to be associated with fat mass." This, as well as the dose response relationship (the human equivalence dose for the amount of PK and MK-4 used in the study would be about 7.5g!) warrant further investigation - and, as always, the SuppVersity is the place to read about it, first!