Vitamin K intake and status are low in hemodialysis patients.
Vitamin K is essential for the activity of γ-carboxyglutamate (Gla)-proteins including matrix Gla28 protein and osteocalcin; an inhibitor of vascular calcification and a bone matrix protein, respectively. Insufficient vitamin K intake leads to the production of non-carboxylated, inactive proteins and this could contribute to the high risk of vascular calcification in hemodialysis patients. To help resolve this, we measured vitamin K(1) and K(2) intake (4-day food record), and the vitamin K status in 40 hemodialysis patients. The intake was low in these patients (median 140 μg/day), especially on days of dialysis and the weekend as compared to intakes reported in a reference population of healthy adults (mean K(1) and K(2) intake 200 μg/day and 31 μg/day, respectively). Non-carboxylated bone and coagulation proteins were found to be elevated in 33 hemodialysis patients, indicating subclinical hepatic vitamin K deficiency. Additionally, very high non-carboxylated matrix Gla28 protein levels, endemic to all patients, suggest vascular vitamin K deficiency. Thus, compared to healthy individuals, hemodialysis patients have a poor overall vitamin K status due to low intake. A randomized controlled trial is needed to test whether vitamin K supplementation reduces the risk of arterial calcification and mortality in hemodialysis patients.
VitaK and Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands.
Ellen C M
EC
Cranenburg
Leon J
LJ
Schurgers
Herma H
HH
Uiterwijk
Joline W J
JW
Beulens
Gerdien W
GW
Dalmeijer
Ralf
R
Westerhuis
Elke J
EJ
Magdeleyns
Marjolein
M
Herfs
Cees
C
Vermeer
Gozewijn D
GD
Laverman
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D002135:Calcium-Binding Proteins / Q000097:blood; D004032:Diet; D019587:Dietary Supplements; D016326:Extracellular Matrix Proteins / Q000097:blood; D005260:Female; D006801:Humans; D008099:Liver / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D018673:Nutrition Policy; D009752:Nutritional Status; D015675:Osteocalcin / Q000097:blood; D011498:Protein Precursors / Q000097:blood; D011516:Prothrombin; D006435:Renal Dialysis; D010837:Vitamin K 1 / Q000008:administration & dosage / Q000097:blood*; D024482:Vitamin K 2 / Q000008:administration & dosage / Q000097:blood*; D014813:Vitamin K Deficiency / Q000097:blood*; D055815:Young Adult; D000097568:Matrix Gla Protein
D015415:Biomarkers; D002135:Calcium-Binding Proteins; D016326:Extracellular Matrix Proteins; D015675:Osteocalcin; D011498:Protein Precursors; D011516:Prothrombin; D010837:Vitamin K 1; D024482:Vitamin K 2; D000097568:Matrix Gla Protein; C008208:acarboxyprothrombin