Vitamin K May Benefit Blood Vessel Health in Dialysis Patients

by | Jan 23, 2014 | 2013, Kidney Health, Vitamin K

Written by Greg Arnold, DC, CSCS. Researchers found that 1080 micrograms of vitamin K-2 caused a 46 % decrease in inactive Matrix Gla Protein, a strong inhibitor of calcification in blood vessels.

The National Institutes of Health estimate that 20 million Americans (1 in 10 American adults) have chronic kidney disease, which costs an average of $70,000 per patient to treat (1). One of the treatment options is dialysis, of which there are two types: hemodialysis (where treatment is done through your bloodstream (2)) and peritoneal dialysis (where treatment is done through your stomach (3)). Patients undergoing hemodialysis are prone to faster rates of blood vessel calcification (4, 5) which increases their risk of death from cardiovascular disease (6, 7).

Now a new study (8) suggests that vitamin K2 may help maintain blood vessel health in hemodialysis patients. In the study, 165 hemodialysis patients were given one of 3 different doses of a form of vitamin K2 (menaquinone) called MK-7 (60 micrograms (59 patients), 720 micrograms (53 patients), or 1080 micrograms (53 patients) per day, 3 days per week) for eight weeks with no placebo group. The patients also completed 3-day food diaries covering a dialysis day, a non-dialysis weekday and a non-dialysis weekend day, including breakfast, lunch, dinner and snacks. Blood samples were provided by the patients before and after the study. MK-7 was chosen because it is a long-chain menaquinone that is quickly absorbed and incorporated into the blood vessel wall, while short-chain menaquinones are much slower to be absorbed (9, 10).

The primary goal of the study was to see if MK-7 would have any effect on the activation of a protein called Matrix Gla Protein (MGP), as it is one of the strongest local inhibitors of vascular calcification in blood vessels. Patients on dialysis have very high levels of inactivated MGP (called “dephosphorylated-uncarboxylated”) so the researchers were hoping that vitamin K2 supplementation would help activate MGP and help maintain blood vessel  health. Three different doses of MK-7 were used, since the best dose to significantly affect MGP activation is currently unknown (11).

By the end of the 8 weeks, those in the highest dose MK-7 group (1080 micrograms) saw a 46% decrease in inactive MGP (3206 to 1719 picomoles/Liter, p < 0.001). Those in the second-highest dose MK-7 group (720 micrograms) saw a 33% decrease (2897 to 1935, p < 0.001). Those in the lowest dose MK-7 group saw a 17% decrease in inactive MGP (2872 to 2306, p < 0.001). Although gastrointestinal side-effects occurred frequently, they were mild and independent of the dose, with 11% of patients complaining of nausea, diarrhea or abdominal discomfort.

While the exact mechanism by which activated Matrix Gla Protein help prevent blood vessel calcification, and admitting that a lack of a placebo group might be considered a limitation of their study, the researchers concluded that “our study shows a dose-dependent decrease in [inactive] MGP by MK-7 supplementation in hemodialysis patients”. They added that decreased MGP levels “may be achieved not only by using high-dose MK-7 supplements, but also by implementing dietary changes to improve vitamin K intake.”

Source: Caluwé, Rogier, et al. “Vitamin K2 supplementation in haemodialysis patients: a randomized dose-finding study.” Nephrology Dialysis Transplantation (2013): gft464.

© The Author 2013. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

Posted January 23, 2014.

Greg Arnold is a Chiropractic Physician practicing in Hauppauge, NY. You can contact Dr. Arnold directly by emailing him at PitchingDoc@msn.com or visiting his web site at www.PitchingDoc.com

References:

  1. Data available on National Institutes of Health’s National Kidney and Urologic Diseases Information Clearinghouse
  2. “Treatment Methods for Kidney Failure: hemodialysis” posted on the National Institutes of Health’s National Kidney and Urologic Diseases Information Clearinghouse website
  3. “Treatment Methods for Kidney Failure: Peritoneal Dialysis” posted on the National Institutes of Health’s National Kidney and Urologic Diseases Information Clearinghouse website
  4. Goodman WG, Goldin J, Kuizon BD et al. Coronary-artery calcification in young adults with end-stage renal disease who are undergoing dialysis. N Engl J Med 2000; 342: 1478–1483
  5. Shroff RC, McNair R, Figg N et al. Dialysis accelerates medial vascular calcification in part by triggering smooth muscle cell apoptosis. Circulation 2008; 118: 1748–1757
  6. Blacher J, Guerin AP, Pannier B et al. Arterial calcifications, arterial stiffness, and cardiovascular risk in end-stage renal disease. Hypertension 2001; 38: 938–942
  7. London GM, Guerin AP, Marchais SJ et al. Arterial media calcification in end-stage renal disease: impact on all-cause and cardiovascular mortality. Nephrol Dial Transplant 2003; 18: 1731–1740
  8. Caluwe R.  Vitamin K2 supplementation in haemodialysis patients: a randomized dose-finding study.  Nephrol Dial Transplant 2013 Nov 26. [Epub ahead of print]
  9. Buitenhuis HC, Soute BA, Vermeer C. Comparison of the vitamins K1, K2 and K3 as cofactors for the hepatic vitamin K-dependent carboxylase. Biochim Biophys Acta 1990; 1034: 170–175
  10. Westenfeld R, Krueger T, Schlieper G et al. Effect of vitamin K2 supplementation on functional vitamin K deficiency in hemodialysis patients: a randomized trial. Am J Kidney Dis 2012; 59: 186–195
  11. Schurgers LJ, Vermeer C. Differential lipoprotein transport pathways of K-vitamins in healthy subjects. Biochim Biophys Acta 2002; 1570: 27–32