Background: Research has shown micronutrient capsules can improve mental wellbeing in clinical and nonclinical recipients, including stress and emotion dysregulation. As previous evidence has shown that individuals can struggle with taking capsules, investigation into alternative modalities of taking micronutrients is important. This thesis investigated the effects of orally absorbed broad-spectrum micronutrients on stress and emotion dysregulation.

Method: To assess the effects of this new modality of taking micronutrients, two randomised trials were conducted. The first study (Study 1) was a double-blind, randomised placebo-controlled trial aiming to investigate the efficacy and safety of treating stress and wellbeing with a broad-spectrum micronutrient powder that is absorbed via the oral mucosa. Seventy-two mild to severely stressed students, assessed using the Depression Anxiety Stress Scale 21 (DASS-21), were randomised to placebo or micronutrients and took one dose per day for four weeks. Symptoms of stress, depression, anxiety, irritability, anger, diet, and side effects were measured with online questionnaires every two weeks.

Study 2 researched the effect of the same broad-spectrum micronutrient product tested in Study 1 on emotion dysregulation in 5-to-10-year-old children using a three-phased randomised open-label waitlist-controlled study design. The primary outcome measures were the Revised Clinician-rated Temper and Irritability Scale (CL-ARI) and the Clinical Global Impressions-Improvement Scale (CGI-I). Forty-eight children with moderate to severe symptoms of irritability were randomised to an initial treatment group (ITG) or a waitlist control group (IWLG), who took the micronutrients with a four-week delayed start. The two groups alternated between taking the micronutrients for four weeks or having a four-week break. For the last three months of the trial, both groups took the micronutrients continuously.

Results: In Study 1, there were no group differences on the primary outcome measures of stress (DASS-21) (d = 0.15, p = .525) and self-reported improvement (Modified Clinical Global Impressions Improvement Scale (M-CGI-I), with 17.1% of the micronutrient and 16.2% of the placebo group identifying themselves as ‘much’ to ‘very much’ improved. However, the micronutrient group experienced a statistically significant greater reduction in irritability (d = 0.54, p = .024) and anger (d = 0.62, p = .011) relative to placebo, measured with the Affective Reactivity Scale (ARI) and the Abbreviated Profile of Mood States (POMS), respectively. No group differences were found on the remaining measures, with both groups showing significant improvements, and there were significantly more headaches and drowsiness reported in the micronutrient group. Belief in treatment assignment was significantly correlated to self-reported improvement (r = -0.247, p = .049). Overall, seven (10%) dropped out with no group differences.

In Study 2, at the end of the RCT phase, the micronutrient group showed largely reduced symptoms of irritability compared to the IWLG (CL-ARI; d = 1.25, p < .001), and 67% in the ITG compared to 8% in the IWLG ‘much’ or ‘very much’ improved (CGI-I). Additionally, the micronutrient group showed large improvements in emotional and behavioural difficulties (Strength and Difficulties Questionnaire (SDQ); d = 1.28, p < .001). The IWLG reported significantly more headaches (p = .040) and sweating (p = .037), and overall adherence rates were high (93%). Overall, seven participants (14.5%) dropped out with no group differences.

Conclusion: This new modality of taking micronutrients was no better than the placebo in reducing stress; however, both studies indicated that orally absorbed micronutrients are safe to take, and Study 2 showed that they can effectively improve emotion dysregulation in children. Future double-blinded, randomised, placebo-controlled trials are needed to support these findings