Functional deficiency of vitamin K in hemodialysis patients in Upper Silesia in Poland (Wyskida K et al.)
Functional vitamin K deficiency (both K1 and K2) is postulated to be one of the most relevant links between chronic kidney disease (CKD) and vascular calcification in hemodialysis (HD) patients. Recommended dietary restrictions in HD patients superimposed on diversity of eating habits across the countries may affect the prevalence of functional vitamin K deficiency.
To that end, research aimed to determine the level of functional vitamin K deficiency and its relation to vitamin K1 intake in HD patients in Upper Silesia in Poland. The results were published in the May issue of Internal Urology and Nephrology.
Protein-induced vitamin K absence or antagonist-II (PIVKA-II) and undercarboxylated matrix Gla protein (ucMGP) were assessed by ELISA in 153 stable, prevalent HD patients and 20 apparently healthy adults (to establish normal ranges for PIVKA-II and ucMGP). Daily phylloquinone intake was assessed using a food frequency questionnaire.
The results showed that PIVKA-II and ucMGP levels were increased in 27.5 and 77.1% of HD patients in comparison with the reference ranges in apparently healthy controls, respectively. In 45% of cases, the increased PIVKA-II level was explained by insufficient phylloquinone intake for Polish population (recommended intake: >55 μ g for women and >65 μg for men). Applying ROC analysis, they showed that vitamin K1 intake below 40.2 μg/day was associated with increased PIVKA-II levels. There was no correlation between vitamin K1 intake and plasma concentration of ucMGP, or between PIVKA-II and ucMGP.
Study authors concluded that Functional vitamin K1 deficiency is explained by low vitamin K1 intake in less than half of HD patients, and that undercarboxylated matrix Gla protein level is a poor surrogate for functional vitamin K1 deficiency.
“The results of this study should increase the knowledge concerning the regional variability of the prevalence of functional vitamin K deficiency in HD patients,” says Dr. Katarzyna Maresz, president of the International Science and Health Foundation. “Moreover, researchers indicated the need for the standardization of methods used for its assessment. It will be interesting to see determination of Vitamin K2, intake not only K1, in this population,” she adds.
Wyskida K, Zak-Golab A, Wajda J, Klein D, Witkowicz J, Ficek R, Rotkegel S, Spiechowicz U, Kocemba Dyczek J, Ciepal J, Olszanecka-Glinianowicz M, Wiecek A, Chudek J. Functional deficiency of vitamin K in hemodialysis patients in Upper Silesia in Poland. Int Urol Nephrol. 2016 May;48(5):765-71. doi: 10.1007/s11255-016-1255-6. Epub 2016 Mar 21.