Carboxylation Level, Vitamin K-dependent Proteins
Conditions
Brief summary
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.
Detailed description
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).
Interventions
DIETARY_SUPPLEMENTplacebo
1 placebo sachet per day containing only sucrose during 12 weeks
DIETARY_SUPPLEMENTvitamin K1
15 µg vitamin K1 per day during 12 weeks
DIETARY_SUPPLEMENTvitamin K2
15 µg vitamin K2 per day during 12 weeks
Sponsors
Maastricht University Medical Center
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Investigator)
Eligibility
Sex/Gender
ALL
Age
40 Years to 60 Years
Healthy volunteers
Yes
Inclusion criteria
* Healthy men and women between 40 and 60 years old * Subjects of normal body weight and height according to BMI \< 30 * Subjects of Caucasian race * Subject has given written consent to take part in the study
Exclusion criteria
* Subjects with (a history of) metabolic or gastrointestinal disease * Subjects presenting chronic degenerative and/or inflammatory disease * Subjects presenting diabetes mellitus * Abuse of drugs and/or alcohol * Subjects receiving corticoϊd treatment including inhalators * Subjects using oral anticoagulants * Subjects using vitamin K containing multivitamins or vitamin K supplements
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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). | 12 weeks | 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| the number or type of bacteria in the stool | 12 weeks | 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. |
Countries
Netherlands
Outcome results
None listed