VN: Vitamin B-12 (2011)
To determine if a group of people following a pure vegetarian diet consuming mostly raw fruits and vegetables, carrot juice and dehydrated barley grass juice would be able to avoid vitamin B12 deficiency through natural means without the use of supplementary vitamin B12.
- Adherence for at least two years, preferably over three years, to a diet popularly referred to as the Hallelujah diet
- Not consumer of vitamin B supplements.
- Adherence to the Hallelujah diet for less than two years
- Consumption of vitamin B supplements.
Subjects were recruited at an annual meeting of health ministers, sponsored by Hallelujah Acres. The meeting was a health education seminar open to people who had previously attended a seminar on implementing the Hallelujah diet.
Randomized controlled trial. Three treatment groups for those determined to be B12 deficient:
- Sublingual B12
- Nutritional yeast supplement
- Probiotic supplement.
Subjects who had elevated urinary MMA concentrations were asked to participate in a follow-up of this initial screening and randomly assigned to three treatment groups. Men and women were randomized separately to evenly divide each sex into the three groups. Group one consumed consumed a sublingual cyanocobalamin tablet for three days a week. Group two daily consumed one tablespoon of nutritional yeast. Group three consumed two capsules of one of two selected probiotic supplements.
The Mann-Whitney rank sum test was used to test whether vitamin B12 intake was correlated with the urinary MMA concentrations. Group mean values before and after supplementation were compared by paired Student's T-test.
Timing of Measurements
A short food frequency questionnaire was used to test for correlations between food consumption and B12 status. Adherence to the Hallelujah diet was assessed using this questionnaire. Exposure to chlorine through municipal water supplies and swimming pools was assessed. Blood samples were drawn and processed in accordance with laboratory guidelines. Serum vitamin B12 concentrations were assayed using immunochemiluminometric method. A spot urine sample was collected from each subject.
- MMA concentrations (measured by urinary assay)
- Serum B12.
Hallelujah diet with either sublingual tablets, nutritional yeast or probiotic supplement.
- Initial N: 49 subjects (17 men, 32 women)
- Attrition (final N): 23 subjects (8 men, 15 women)
- Age: Average age 55±9 (SD) years
- Location: US.
- Most subjects followed the diet for 23 to 49 months
- Eight men and 15 women had urinary MMA concentrations above or equal to 4.0mcg per mg creatinine
- 16 subjects had urinary MMA concentrations equal to or above 5.0mcg per mg creatinine
- Two subjects had serum B12 concentrations less than 147pmol per L, but had normal urinary MMA concentrations
- There was no correlation between MMA and intake of vitamin B12 from foods, length of time following a meatless diet, length of time following the hallelujah diet or exposure to chlorinated water
- Sublingual cyanocobalamin (P<0.01) and nutritional yeast (P<0.05) significantly reduced all MMA concentrations
- Seven of eight subjects’ MMA concentrations returned to normal using the sublingual tablet
- Five of eight subjects’ MMA concentrations returned to normal using the nutritional yeast and all eight subjects showed improvement
- The difference in the group mean MMA level before and after supplementation with probiotics was not significant.
- The results are in agreement with the average of all other studies, that about 50% of vegans have below-normal cobalamin status
- Evidence points towards the need for all vegans to supplement their diets with cobalamin or to monitor their vitamin B12 status. There was no correlation with length of time following a vegan diet or within take with cobalamin.
- The small sample of subjects taking the probiotic supplement prevented the improvement in B12 status from being statistically significant. More studies are needed to determine whether a population of bowel flora could be maintained in adult subjects that produced enough cobalamin to meet nutritional requirements.
- While nutritional yeast appears to be an effective mode of delivery of cobalamin, dietary cobalamin and cobalamin supplementation are the only proven method for normalizing cobalamin status
- We showed that urinary MMA assay was more effective than the serum cobalamin assay in identifying individuals at risk of vitamin B12 deficiency and in monitoring improvement of cobalamin status
- Our results indicate that shortly after stopping intake of vitamin B12, its metabolism is unfavorably altered by the lack of vitamin B12, though liver stores are not depleted. This information has not been widely recognized.
- Early detection and supplementation among pure vegetarians is the best way to circumvent permanent neurological damage and disorders.
Quality Criteria Checklist: Primary Research
|1.||Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies)||Yes|
|2.||Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about?||Yes|
|3.||Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice?||Yes|
|4.||Is the intervention or procedure feasible? (NA for some epidemiological studies)||Yes|
|1.||Was the research question clearly stated?||Yes|
|1.1.||Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified?||Yes|
|1.2.||Was (were) the outcome(s) [dependent variable(s)] clearly indicated?||Yes|
|1.3.||Were the target population and setting specified?||???|
|2.||Was the selection of study subjects/patients free from bias?||No|
|2.1.||Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study?||Yes|
|2.2.||Were criteria applied equally to all study groups?||Yes|
|2.3.||Were health, demographics, and other characteristics of subjects described?||No|
|2.4.||Were the subjects/patients a representative sample of the relevant population?||No|
|3.||Were study groups comparable?||Yes|
|3.1.||Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT)||Yes|
|3.2.||Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline?||Yes|
|3.3.||Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.)||Yes|
|3.4.||If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis?||N/A|
|3.5.||If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.)||N/A|
|3.6.||If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")?||N/A|
|4.||Was method of handling withdrawals described?||Yes|
|4.1.||Were follow-up methods described and the same for all groups?||Yes|
|4.2.||Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.)||Yes|
|4.3.||Were all enrolled subjects/patients (in the original sample) accounted for?||Yes|
|4.4.||Were reasons for withdrawals similar across groups?||N/A|
|4.5.||If diagnostic test, was decision to perform reference test not dependent on results of test under study?||N/A|
|5.||Was blinding used to prevent introduction of bias?||No|
|5.1.||In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate?||No|
|5.2.||Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.)||Yes|
|5.3.||In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded?||N/A|
|5.4.||In case control study, was case definition explicit and case ascertainment not influenced by exposure status?||N/A|
|5.5.||In diagnostic study, were test results blinded to patient history and other test results?||N/A|
|6.||Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described?||Yes|
|6.1.||In RCT or other intervention trial, were protocols described for all regimens studied?||Yes|
|6.2.||In observational study, were interventions, study settings, and clinicians/provider described?||N/A|
|6.3.||Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect?||Yes|
|6.4.||Was the amount of exposure and, if relevant, subject/patient compliance measured?||Yes|
|6.5.||Were co-interventions (e.g., ancillary treatments, other therapies) described?||N/A|
|6.6.||Were extra or unplanned treatments described?||N/A|
|6.7.||Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups?||Yes|
|6.8.||In diagnostic study, were details of test administration and replication sufficient?||N/A|
|7.||Were outcomes clearly defined and the measurements valid and reliable?||Yes|
|7.1.||Were primary and secondary endpoints described and relevant to the question?||Yes|
|7.2.||Were nutrition measures appropriate to question and outcomes of concern?||Yes|
|7.3.||Was the period of follow-up long enough for important outcome(s) to occur?||Yes|
|7.4.||Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures?||Yes|
|7.5.||Was the measurement of effect at an appropriate level of precision?||Yes|
|7.6.||Were other factors accounted for (measured) that could affect outcomes?||Yes|
|7.7.||Were the measurements conducted consistently across groups?||Yes|
|8.||Was the statistical analysis appropriate for the study design and type of outcome indicators?||Yes|
|8.1.||Were statistical analyses adequately described and the results reported appropriately?||Yes|
|8.2.||Were correct statistical tests used and assumptions of test not violated?||Yes|
|8.3.||Were statistics reported with levels of significance and/or confidence intervals?||No|
|8.4.||Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)?||N/A|
|8.5.||Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)?||No|
|8.6.||Was clinical significance as well as statistical significance reported?||Yes|
|8.7.||If negative findings, was a power calculation reported to address type 2 error?||No|
|9.||Are conclusions supported by results with biases and limitations taken into consideration?||Yes|
|9.1.||Is there a discussion of findings?||Yes|
|9.2.||Are biases and study limitations identified and discussed?||Yes|
|10.||Is bias due to study's funding or sponsorship unlikely?||Yes|
|10.1.||Were sources of funding and investigators' affiliations described?||Yes|
|10.2.||Was the study free from apparent conflict of interest?||???|