Did you know…

In the Rotterdam Study, higher dietary vitamin K2 intake was linked to a 52% reduction in severe aortic calcification and a 41% lower cardiovascular mortality over seven years. Vitamin K1, the form present in green leafy vegetables and the target of most fortification and supplementation, showed no such association. The two forms of vitamin K are not interchangeable for cardiovascular biology.

The claim, in the reference of population cardiology

The Rotterdam Study is one of the most-cited prospective cohorts on cardiovascular epidemiology. Its 2004 analysis of vitamin K intake in 4,807 subjects free of CVD at baseline established the association that has anchored the K2 field ever since:

“Dietary intake of vitamin K2 was inversely associated with aortic calcification, all-cause, and CAD mortality, whereas K1 was not linked with any of these outcomes.”

— Rotterdam Study analysis, 2004

The specific magnitudes: -52% severe aortic calcification, -41% coronary heart disease mortality, in the highest tertile of dietary K2 intake compared to the lowest, over seven years of follow-up.

The mechanism, in one sentence

Matrix Gla Protein (MGP) is a small vitamin-K-dependent protein secreted by vascular smooth muscle cells that, when carboxylated by vitamin K, binds calcium and redirects it away from arterial walls. Uncarboxylated MGP, which is what circulates in vitamin K2 deficiency, cannot bind calcium. The calcium then deposits where it should not.

What the standard fortification does

Vitamin K fortification, where it exists, addresses K1. Warfarin, the anticoagulant that has anchored the vitamin K conversation in cardiology for sixty years, works by blocking the recycling of vitamin K for coagulation and, incidentally, blocks it for MGP activation. Neither the fortification programs, nor the standard supplement, nor the anticoagulation infrastructure, treat K2 as a separate physiological parameter deserving of measurement. It is not measured in any ordinary panel.

This entry is a companion piece to fiches on cardiovascular nutrition and to arguments on the asymmetry between what medicine measures and what it treats.