An interventional study of placebo and vitamin K1 in Carboxylation Level and Vitamin K-dependent Proteins, sponsored by Maastricht University Medical Center. Completed at 1 site in Netherlands. Open to participants aged 40 Years to 60 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2010-09-03.
Sponsored by Maastricht University Medical Center · Not applicable, Interventional, and Treatment
Vitamin K is a group name for a number of compounds: K1 is present in chloroplasts in green vegetables, K2 is of microbial origin. Lactic bacteria produce a mixture of higher menaquinones, including menaquinone-7, menaquinone-8, and menaquinone-9. Nothing is known yet about the efficacy of bacterial K2 vitamins for in vivo K function (carboxylation of essential proteins). Therefore, this study was undertaken to study effects of different dosages of bacterial vitamin K2 on carboxylation of extrahepatic proteins.
Vitamin K is a group name for a number of compounds: K1 is present in chloroplasts in green vegetables, K2 is of microbial origin. Lactic bacteria produce a mixture of higher menaquinones, including menaquinone-7, menaquinone-8, and menaquinone-9. Higher menaquinones not only have very long half-life times (over 3 days rather than 1 hour for vitamin K1); K2 vitamins are also transported to extra hepatic tissues such as bone and vessel wall whereas K1 is preferentially transported to the liver. Nothing is known yet about the efficacy of bacterial K2 vitamins for in vivo K function (carboxylation of essential proteins). This study describes a dose-response experiment for different dosages of bacterial K2 which are compared with one selected dose of K1 and placebo. The efficacy is concluded from the carboxylation of the bone Gla-protein osteocalcin and of the vascular Gla-protein matrix-Gla protein (MGP).
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Exclusion Criteria:
The participants of the placebo group will receive daily 1 placebo sachet containing only sucrose
Dietary Supplement: placebo
The participants of this group will receive daily 1 sachet containing 15 µg vitamin K1.
Dietary Supplement: vitamin K1
The participants of this group will receive daily 1 sachet containing 15 µg vitamin K2
Dietary Supplement: vitamin K2
The participants of this group will receive daily 1 sachet containing 30 µg vitamin K2
Dietary Supplement: vitamin K2
The participants of this group will receive daily 1 sachet containing 45 µg vitamin K2.
Dietary Supplement: vitamin K2
1 placebo sachet per day containing only sucrose during 12 weeks
15 µg vitamin K1 per day during 12 weeks
15 µg vitamin K2 per day during 12 weeks
30 µg vitamin K2 per day during 12 weeks
45 µg vitamin K2 per day during 12 weeks
The concentration of the circulating biochemical markers matrix-Gla protein and osteocalcin. Both proteins will be measured in their active form (carboxylated form) and their inactive form (undercarboxylated form).
The main purpose of the study is to investigate the efficacy of different dosages bacterial vitamin K2 and vitamin K1 on carboxylation degree of the vitamin K-dependent proteins osteocalcin and matrix-gla protein.
Time frame: 12 weeks
the number or type of bacteria in the stool
The second purpose of the study is to monitor whether the increased vitamin K intake will change the composition of the intestinal flora, as measured from the collected stools. Vitamin K, notably K2 is produced by a number of colonic bacteria and our principal is interested to learn whether the intake of extra vitamin K will affect the number or type of bacteria in the stool.
Time frame: 12 weeks
This study is completed, as verified in Sep 2010. You cannot join it, but the record below documents what was studied.
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Maastricht University Medical Center