Comparison of menaquinone-4 and menaquinone-7 bioavailability in healthy women

Abstract

BackgroundVitamin K2 contributes to bone and cardiovascular health. Therefore, two vitamin K2 homologues, menaquinone-4 (MK-4) and menaquinone-7 (MK-7), have been used as nutrients by the food industry and as nutritional supplements to support bone and cardiovascular health. However, little is known about the bioavailability of nutritional MK-4. To investigate MK-4 and MK-7 bioavailability, nutritional doses were administered to healthy Japanese women.FindingsSingle dose administration of MK-4 (420 μg; 945 nmol) or MK-7 (420 μg; 647 nmol) was given in the morning together with standardized breakfast. MK-7 was well absorbed and reached maximal serum level at 6 h after intake and was detected up to 48 h after intake. MK-4 was not detectable in the serum of all subjects at any time point. Consecutive administration of MK-4 (60 μg; 135 nmol) or MK-7 (60 μg; 92 nmol) for 7 days demonstrated that MK-4 supplementation did not increase serum MK-4 levels. However, consecutive administration of MK-7 increased serum MK-7 levels significantly in all subjects.ConclusionsWe conclude that MK-4 present in food does not contribute to the vitamin K status as measured by serum vitamin K levels. MK-7, however significantly increases serum MK-7 levels and therefore may be of particular importance for extrahepatic tissues.

Bioavailability and Chemical/Functional Aspects of Synthetic MK-7 vs Fermentation-Derived MK-7 in Randomised Controlled Trials

“…Only a few studies have investigated the bioavailability and single-dose kinetics of MK-7 [9,15,29,30]. In a recent study, Knapen and colleagues compared the bioavailability of MK-7 in four clinical trials using different formulations of capsules and tablets [28].…”

Vitamin K: an old vitamin in a new perspective

“…Therefore, the small quantities of MK-4 contained in the diet do not contribute to the buildup of vitamin K status or to the degree of carboxylation of vitamin K-dependent proteins. 50 …”

“…4, 5). 48,49 Compared with MK-7, no oral bioavailability has been determined for MK-4 at nutritional doses (e.g., 420 mg MK-4). Therefore, the small quantities of MK-4 contained in the diet do not contribute to the buildup of vitamin K status or to the degree of carboxylation of vitamin K-dependent proteins.…”

Role of nutritional factor menaquinone-7 in bone homeostasis and osteoporosis prevention

“…Serum levels of MK-7 absorbed by intestine were reached to maximal levels at 6 hours after intake, and its levels were detected up to 48 hours after intake with a single dose administration of MK-4 (420 μg; 945 nmol) or MK-7 (420 μg; 647 nmol) [9]. MK-4 was not detectable in the serum of all subjects at any time point, while MK-7 was significantly increased serum MK-7 levels in all subjects [9]. From these findings, it has been assumed that MK-4, which is present in food, may not contribute to the vitamin K status as estimated by serum vitamin K levels [9].…”

“…Bioavailability of MK-4 and MK-7 with nutritional doses has been examined in healthy Japanese women [9]. Serum levels of MK-7 absorbed by intestine were reached to maximal levels at 6 hours after intake, and its levels were detected up to 48 hours after intake with a single dose administration of MK-4 (420 μg; 945 nmol) or MK-7 (420 μg; 647 nmol) [9].…”