Design:
Monocentric double-blind experiment
Scientific background:
Vitamin B-complex is water-soluble and essential for humans. Vitamin B deficiency is associated with neurologic diseases, heart insufficiency, diminished hormone production and maldigestion. Due to the fact that literature search did not reveal distinct information about natural versus synthetic Vitamin B-complexes this study was initiated to investigate bioavailability and long-term effects of natural Vitamin B-complexes in comparison to synthetic Vitamin B-complexes.
Vitamin B complex was filled in hydroxypropylmethylcellulose capsules (size 0, ivory-coloured). Daily dose = 3 capsules in the morning with 250ml water.
Blinding/Randomization:
The person in charge for manufacturing and blinding arranged an identical packaging of both verum as well as synthetic Vitamin B-complex. Each package consists of 126 capsules per subject and period. Each product was tagged with the subject-number and period (period I and period II).
Study-subjects were blinded by the person in charge for randomization through a sealed envelope. The allocation was in the relation of 1:1 between group A (verum in period I and synthetic Vitamin B-complex in period II) and group B (synthetic Vitamin B-complex in period I and verum in period II). The ultimate subject list was forwarded to the person in charge for randomization after the run-in phase.
Method:
Blood sampling:
Blood (max. 20ml) was collected in a seated position from an antecubital vein.
Time schedule:
Run-in-phase: 3 weeks (no supplementation) Determination of inclusion criteria, nutrition advice, randomization.
Phase I: 6 weeks (supplementation) Group A - natural Vitamin B-complex supplementation every day Group B - synthetic Vitamin B-complex supplementation every day
Blood sampling:
First day:
Fasting value (basic) - Vitamin B-complex supplementation - After 1.5 hours After 4 hours After 7 hours
End of first supplementation:
After 6 weeks
Wash-out period: 2 weeks (without supplementation)
Phase II: 6 weeks (supplementation) Group A - synthetic Vitamin B-complex supplementation every day Group B - natural Vitamin B-complex supplementation every day
Blood sampling:
First day:
Fasting value (basic) - Vitamin B-complex supplementation - After 1.5 hours After 4 hours After 7 hours
End of second supplementation:
After 6 weeks
Wash-out period II: 6 weeks (without supplementation) Final exam - last blood sampling
Drop-out-criteria:
Drawback Compliance (\<80% of Vitamin B-complexes) Supplementation of Vitamin B-complexes during run-in-phase or wash-out periods
Primary-target parameters:
Serum concentrations for vitamins B1, B2, B6, B9 and B12
Secondary-target biomarkers:
Serum concentrations for Total antioxidants, total peroxides, peroxidase-activity, polyphenols and homocysteine.
Biometry:
Comparison of interventions in a cross-over approach descriptive and exploratory.
Group comparison: Parametric and non-parametric cross-over comparison Gaussian distribution - (Kolmogorov-Smirnov-test with Lilliefors-significances, alpha =10%).
Effect size: Two-sided 95%-confidence intervals
Analysis:
Intent-to-treat-analysis Per-protocol-analysis Full analysis set
Vitamin B and Homocysteine analysis was done in a routine laboratory. Antioxidants (TAC), peroxidase-activity (EPA), peroxides (TOC) and polyphenols (PPm) were measured by the use of commercially available microtitre assays at a wavelength of 450 vs. 620 nm. In case of PPm a wavelength of 766nm was used.
Implausible values will be scored as missing values. Missing values are not substituted.
Presentation of results:
Minimum-Median-Quartiles-Maximum-Mean-Standard deviation. Box Plots, Bar graph, tables.
