Vitamins K and D Status in Stages 3–5 Chronic Kidney Disease

TLDR

The study measured vitamin K and D status in 172 stage 3–5 CKD patients using dietary intake, plasma phylloquinone, percent uncarboxylated osteocalcin (%ucOC), PIVKA‑II, vitamin K epoxide reductase SNP, apolipoprotein E genotype, and 25(OH)D, and assessed nutritional status by subjective global assessment. In these patients, suboptimal vitamin K and D status is common and is associated with poorer nutritional markers, higher proteinuria, and adverse mineral metabolism, while higher dietary vitamin K intake and 25(OH)D levels correlate with better weight stability, albumin, and lower PIVKA‑II.

Abstract

Vitamin K, vitamin K-dependent proteins, and vitamin D may be involved in the regulation of calcification in chronic kidney disease (CKD).Vitamin K and D status was measured as dietary intake, plasma phylloquinone, serum percent uncarboxylated osteocalcin (%ucOC), proteins induced by vitamin K absence (PIVKA-II), Vitamin K Epoxide Reductase single-nucleotide polymorphism, apolipoprotein E genotype, and plasma 25-hydroxyvitamin D (25(OH)D) in 172 subjects with stage 3 to 5 CKD. Nutritional status was determined by subjective global assessment.Subclinical vitamin K deficiency criteria was met by 6% (phylloquinone), 60% (%ucOC), and 97% (PIVKA-II) of subjects, whereas 58.3% and 8.6% had 25(OH)D insufficiency and deficiency, respectively. Dietary vitamin K intake was associated with higher phylloquinone and lower PIVKA-II. There were positive correlations between phylloquinone and the presence of stable weight, and the absence of subcutaneous fat loss or muscle wasting. 25(OH)D levels were positively associated with stable weight and albumin (P < 0.001). PIVKA-II levels were associated with apolipoprotein E genotype. Higher %ucOC and lower 25(OH)D were similarly associated with CKD stage, parameters of mineral metabolism, and urine albumin to creatinine ratio.These data indicate that a suboptimal vitamin K and D status is prevalent in patients with CKD. Sufficiency of both vitamins K and D was similarly predicted by measures of overall improved nutritional status. Proteinuria was associated with both a suboptimal vitamin D status as well as worse peripheral vitamin K status.