The most meaningful (and exciting) new data on vitamin K is on it’s relationship with coronary heart disease (CHD), but it’s a bit confusing.
A cross-sectional study published in Atherosclerosis in 2009 indicated menaquinone reduced coronary calcification, but maybe not phylloquinone (1). This supported a hypothesis made earlier that menaquinone, but not phylloquinone reduced risk of cardiovascular disease (2).
However, an intention-to-treat analysis in Am J Clin Nutr also published this year found phylloquinone supplementation appeared to slow coronary artery calcification (3). This study was performed on older adults with preexisting calcification (3).
One more piece of the puzzle is another not-yet-published September cohort study from Nutr Metab Cardiovasc Dis (4). The study followed 16,057 women ages 49-79 who did not have CHD at baseline (4). Questionnaires were used to determine estimation of vitamin K intake and multivariates were reduced as needed (4). According to its conclusions, menaquinones may have preventative effects against CHD, but not phylloquinone (4).
Eventually more studies will be needed to shed more light on the roles of both phylloquinone and menaquinone and, ultimately, the research will reveal best intake levels for CHD prevention.
1. Beulens JW, Bots ML, Atsma F et al. High dietary menaquinone intake is associated with reduced coronary calcification. Atherosclerosis 2009;203:489-93.
2. Erkkila AT, Booth SL. Vitamin K intake and atherosclerosis. Curr Opin Lipidol 2008;19:39-42.
3. Shea MK, O'Donnell CJ, Hoffmann U et al. Vitamin K supplementation and progression of coronary artery calcium in older men and women. Am J Clin Nutr 2009;89:1799-807.
4. Gast GC, de Roos NM, Sluijs I et al. A high menaquinone intake reduces the incidence of coronary heart disease. Nutr Metab Cardiovasc Dis 2009;19:504-10.