Vitamin K1 and K2 in the Diet of Patients in the Long Term after Kidney Transplantation

Abstract

Vitamin K, especially its K2 form, is considered to be a protective factor against developing vascular changes and bone lesions that are common complications in kidney transplant (KTx) recipients. There is a growing number of studies showing that KTx patients are at risk of vitamin K deficiency. The aim of this study was to evaluate the intake of vitamin K1 and K2 in the diet of patients in the late period after KTx. During a routine visit at one outpatient transplantation clinic in Central Europe, a diet survey questionnaire was filled in by 151 clinically stable KTx recipients and compared with medical history, anthropometric measurements and laboratory tests. Mean vitamin K1 intake was 120.9 ± 49 μg/day and vitamin K2 (MK, menaquinone) intake 28.69 ± 11.36 μg/day, including: MK-4: 25.9 ± 9.9 μg/day; MK-5: 0.1 ± 0.2 μg/day; MK-6: 0.2 ± 0.4 μg/day; MK-7: 0.2 ± 0.23 μg/day; MK-8: 1 ± 1.9 μg/day; MK-9: 0.9 ± 2.3 μg/day; and MK-10: 0.2 ± 0.5 μg/day. Our study showed that KTx recipients’ diets contained adequate amounts of vitamin K1, whereas the intake of vitamin K2 seemed insufficient.

Effect of vitamin K on improving post‑kidney transplant outcomes: a meta‑analysis

“…The present meta-analysis found that vitamin K status or supplementation of vitamin K was not related to systolic blood pressure, diastolic blood pressure, triglycerides, hemoglobin, calcium, or 25-hydroxyvitamin D in patients receiving kidney transplantation. A possible reason may be that the disease conditions were complicated in patients after kidney transplantation, and the change of a single factor (vitamin K) does not greatly influence these vascular and bone health indexes; thus, the benefits of vitamin K alone in improving vascular and bone health would not be notable ( 27 , 33 , 34 ). Heterogeneity of systolic blood pressure, triglycerides, hemoglobin, calcium, and 25-hydroxyvitamin D existed among the analyzed studies; meanwhile, sensitivity analysis found that omitting Boxma et al ( 14 ) and Lees et al ( 19 ) affected the results of systolic blood pressure and hemoglobin, respectively.…”