A total of 182 participants were enrolled in the study, of these 138 received treatment. An attrition rate of approximately 16% was observed, with 116 participants completing the study (Figure
). Qualitative data was available from 114 participants, 59 from the placebo group and 55 from the SMV group. A count of returned tablets indicated that all participants satisfied the 80% compliance requirement at their final visit. The characteristics of the sample (Table
) revealed that the mean age of participants was early 30s, they were educated and had higher than average intelligence, low depression and anxiety levels, and an average BMI (for adult Australians). The two treatment groups did not differ significantly on any examined demographic characteristic, either in the sample as a whole or when split by gender.
Trial design and visit completion. *One participant from the Multivitamin group and one participant from the Placebo group failed to provide qualitative data.
Baseline characteristics of participants (n=114)*
Overview of qualitative data
The qualitative data were divided into “Positive Effects” or “Negative Effects” and coded into four primary domains, in addition to supplementary analysis of any unusual experiences. A total of 21 further emergent themes were found and coded under these main domains (see Table
). Examples of participants’ experiences are detailed below. Statements are provided that best represent the themes revealed from qualitative analysis. As a result, some participants’ responses are not included, while others are quoted more than once.
Experiential themes identified
Summary of positive and negative experiences
In response to the question posed to participants about any positive effects, the majority of participants (60.0%) in the SMV group reported at least one positive experience compared to those in the placebo group (50.8%; Table
). In the area of positive reported effects, the two main statistically significant themes identified in the SMV group over the placebo group were an increase in energy and mental alertness, and an increase in mood and mental/emotional wellbeing. More people in the SMV group reported sleep improvement compared to placebo, but due to low power the result did not reach statistical significance. Curiously, two participants reported a beneficial change in appetite, while one person (placebo group) said their skin was better. Of the negative effects reported, no significant differences were found between SMV and placebo (further detail below).
Differential positive and negative effects experienced by participants
Multivitamin effects on energy levels
A total of 17.2% more participants in the SMV group significantly reported increased energy levels and mental alertness compared to the placebo group (p =.022). Females in the SMV group significantly (p =.020) reported experiences of increased energy and mental alertness than females in the placebo group (22.5% difference). Positive perceived effects on participant’s energy levels commonly reported in the SMV group included:
"“More alert, bright, full of energy”"
"“I found getting up early…easier”"
"“Have felt like I have more energy”"
"“I feel some sort of relaxation and energy”"
"“My energy levels were quite good over the period and I felt happy most of the time”"
"“A general feeling of more alertness particularly in the morning”"
"“I felt physically less tired”"
Multivitamin effects on mood and stress
Compared with the placebo group, a total of 15.1% more participants in the SMV group reported the experience of better mood and emotional state. This difference was statistically significant (p = .027). While nearly 20% more female participants reported an improvement of mood in the SMV compared to control, the result did not reach significance (p =.054). Examples of beneficial experiences reported by the SMV group in the area of enhanced mood and reduced stress were:
"“I feel a bit more carefree and I stress less”"
"“I have felt more relaxed; mood is more stable, less ups and downs”"
"“Stress levels have reduced… Feel calmer”"
"“Mood more uplifted”"
"“Much more calm than before taking this”"
"“Mood-wise I think I am more patient”"
Multivitamin effects on sleep
Another theme that emerged was the experience by some participants of an improvement in their sleep. While 10% more participants in the SMV group reported a positive effect on sleep, this was just outside of significance (p =.087). Examples of beneficial effects in the SMV group:
"“Less tired/easier to fall asleep""
"“Sleep quite peaceful… Increased my sleep during the night”"
"“Felt that tablets assisted in helping to sleep”"
"“Better sleep, less stress, more energy during the day time”"
Perceived negative experiences
Importantly, no major adverse effects or reactions emerged from our thematic analysis, providing additional support for the quantitative finding that SMV was well tolerated by this sample. Overall SMV was well-tolerated with no statistical difference in the number of overall negative effects reported between the placebo (28.8%) and MV (30.9%) groups. Negative mental effects were not different between groups. Specifically, three females reported feeling more ‘moody’ or ‘emotional’ compared to none in the placebo group. Five participants experienced impaired concentration/alertness (two SMV, three placebo) three were more stressed or anxious (two SMV, one placebo), however this was not significantly different between groups.
Several participants reported experiencing mild negative physical reactions that occurred during the study. The most common complaint related to participants feeling dehydrated or need to drink soon after taking the tablets; experiencing heartburn; or an unpleasant taste. While 7% more participants in the SMV than the placebo group reported mild negative gastrointestinal effects, this was just outside of statistical significance (p=.077). Another negative experience included two females in the SMV noting they had a negative gynaecological effect (one perceived an increase in premenstrual symptoms, and the other a change in her menstrual cycle). Two participants in the placebo group and one participant in the multivitamin group reported weight gain. Impaired sleep, dermatological complaints (rash or dry skin/nails) and more frequent illness were each reported by single participants in both groups.
Unusual experiences reported
Six unusual effects were reported by participants, although it cannot be determined whether these experiences were related to either group’s intervention. For the SMV group, three unusual effects were reported: “Early on I felt that I sweated more - under the arms” “Faeces more hard perhaps” “Sensitive to the room temperature when sleeping”.
A total of 3 people in the placebo group reported unusual effects: “I experienced fuzzy eyes” “Several mornings I woke up with a headache” “Kidney-ache occurred for the last six weeks… Quite intense about 4 weeks ago”.