The British Medical Journal recently published an observational study that examined the association between intakes of vitamins K1 and K2 and incidence of coronary heart disease (CHD). The 11-year Norwegian community-based prospective cohort did indeed show a link between K2 intakes and a lower risk of subsequent CHD events, building the evidence that K2’s impact on calcification can greatly improve health outcomes.
According to “Association of dietary vitamin K and risk of coronary heart disease in middle-age adults: the Hordaland Health Study Cohort”[1], the role of vitamin K in the regulation of vascular calcification is established, and that patients with both medial and intimal calcification have a higher cardiovascular risk when compared with similar patients without calcification. Therefore, an inverse association between vitamin K intake and coronary heart disease (CHD) could be expected. The purpose of the current study was to evaluate the association between intake of both K1 and K2 and subsequent CHD events among community-living middle-aged adults in Norway.
The researchers concluded “a higher intake of vitamin K2 was associated with lower risk of CHD, while there was no association between intake of vitamin K1 and CHD.”
The paper is significant because it not only adds to the growing body of evidence substantiating vitamin K2 as a cardiovascular-support nutrient, according to NattoPharma Chief Medical Officer Dr. Hogne Vik, but it helps to clarify the confusion that “vitamin K is vitamin K,” also confirming the need for a K2-specific recommended daily intake (RDI).
“NattoPharma has driven the research confirming vitamin K2’s important health benefits, showing in human studies with healthy[2] and patient participants that the progression of hardening of the arteries can be halted and even regressed with daily supplementation of MenaQ7 Vitamin K2,” says Dr. Vik, noting that this study builds on the body of evidence linking vitamin K status to health concerns such as peripheral arterial disease (PAD)[3], coronary calcification[4], dementia[5], vascular stiffness in chronic kidney disease patients (CKD)[6] and more. “The common link is calcification and the need for adequate vitamin K2 intakes to inhibit this in our circulatory system and tissues. Due to its very molecular structure, vitamin K2 can move beyond the liver to support other systems of the body, such as the bones and vasculature, where K1 cannot. There remains a great deal of confusion that K1 supports both bone and heart health, and this paper helps to identify the difference between the two in that K1 is not linked to cardiovascular health, whereas K2 is linked to both.
“These results mirror what we have seen in epidemiological studies, where populations who consume a lot of dietary Vitamin K2 have healthier hearts and more flexible arteries,” Vik adds. “Recognition of vitamin K2’s benefits as strong and significant elucidated inhibitor of vascular and soft tissue calcification is one of the core reasons a separate RDI should be established.”
Researchers followed participants (2,987 Norwegian men and women aged 46-49 years) in the community-based Hordaland Health Study from 1997 – 1999 through 2009 to evaluate associations between intake of vitamin K and incident (new onset) CHD. Baseline diet was assessed by a past-year food frequency questionnaire. During a median follow-up time of 11 years, we documented 112 incident CHD cases.
In the adjusted analyses, there was no association between intake of vitamin K1 and CHD (HRQ4vsQ1 = 0.92 (95% CI 0.54 to 1.57), p for trend 0.64), while there was a lower risk of CHD associated with higher intake of energy-adjusted vitamin K2 (HRQ4vsQ1 = 0.52 (0.29 to 0.94), p for trend 0.03). Further adjustment for potential dietary confounders did not materially change the association for K1, while the association for K2 was slightly attenuated (HRQ4vsQ1 = 0.58 (0.28 to 1.19)).
Given the limited number of epidemiological studies, and the fact that dietary vitamin K sources and content differ between countries, the researchers noted that further research is warranted.
References:
1 Haugsgjerd TR, Egeland GM, Nygård OK, et al. Association of dietary vitamin K and risk of coronary heart disease in middle-age adults: the Hordaland Health Study Cohort. BMJ Open 2020;10:e035953. doi:10.1136/bmjopen-2019-035953.
2 Knapen MHJ, Braam LAKJLM, Drummen NE, Bekers O, Hoeks APG, Vermeer C. Menaquinone-7 Supplementation Improves Arterial Stiffness in Healthy Postmenopausal Women. A Double-Blind Randomised Clinical Trial. Thromb Haemost. 2015 May;113(5):1135-44.
3 Vissers LET, Dalmeijer GW, Boer JMA, Verschuren WMM, van der Schouw YT, Beulens JWJ. The relationship between vitamin K and peripheral arterial disease. Atherosclerosis 252 (2016) 15e20.
4 Wei FF, Thijs L, Cauwenberghs N, Yang WY, Zhang ZY, Yu CG, Kuznetsova T, et al. Central Hemodynamics in Relation to Circulating Desphospho-Uncarboxylated Matrix Gla Protein: A Population Study. J Am Heart Assoc. 2019;8:e011960. DOI: 10.1161/JAHA.119.011960.
5 Cui C, Sekikawa A, Kuller LH, Lopez OL, Newman AB, Kuipers AL, Mackey RH. Aortic stiffness is associated with increased risk of incident dementia in older adults. J Alzheimer’s Dis. 2018;66(1):297-306.
6 Thamratnopkoon S, Susantitaphong P, Tumkosit M, Katavetin P, Tiranathanagul K, Praditpornsilpa K, Eiam-Ong S. Correlations of Plasma Desphosphorylated Uncarboxylated Matrix Gla Protein with Vascular Calcification and Vascular Stiffness in Chronic Kidney Disease. Nephron. 2017;135(3):167-172.
