Brief Trial Information

More detailed trial information will be sent to you once initial eligibility is confirmed.

What is a randomised controlled trial (RCT)?
This double blind, randomised controlled trial is exploring whether or not the micronutrients zinc and vitamin B6 may improve symptoms of generalised anxiety in adult females.

The RCT is viewed as the gold standard for testing whether or not treatments work. Participants will be randomly assigned to one of two groups.  The groups consist of the treatment group (who will receive micronutrients) and the placebo group (who will receive an identical product that contains no micronutrients).

Both groups will take placebo or micronutrients for 6 weeks. At the end of the 6 week trial period, participants will be offered the opportunity to take the micronutrients for a further 6 weeks, regardless of which group they were in. That way, everyone who participates in the study has the chance to try the micronutrient intervention.

Micronutrients are not a proven treatment for symptoms of anxiety and depression. For more information about treatments for symptoms of anxiety and depression, please speak to your GP or mental health professional.

What does participation in the trial involve?

We will be recruiting 120 participants who are experiencing symptoms of generalised anxiety and who are not currently taking any psychiatric medication to take part in this trial. You do not have to be diagnosed with generalised anxiety disorder to participate. Please let us know if you are currently taking any psychiatric medication as we do not want you to stop taking medication in order to be in this trial. Please CONTINUE to take any medications and discuss any decision to stop taking medication with your GP.

Participants (females only) will be recruited nationally throughout New Zealand by self-referral and referral from their GP (we will contact your GP on your behalf).

If you decide to participate in this study, you will enter an eligibility screening process. This screening will be a online questionnaire to collect health, well-being and demographic information. Inclusion and exclusion criteria will also be assessed. If you are eligible, a 45-minute introduction telephone call will be scheduled to explain the study and go over informed consent. Once informed consent is received, from you and your GP, you can progress onto baseline data collection where various online health questionnaires and a urine test will be completed. A 15-minute coaching call will be scheduled to ensure accurate collection of the urine sample. At this stage, you will be randomised into either the active or the placebo condition. 

We will ask you to complete various health questionnaires on-line at day 14, 28 and 42 of the study. These questionnaires will assess your mood, your stress levels and anxiety as well as some questions directed at asking about general health. At the end of the 6-week trial you will be asked to provide another urine sample.

The next phase of the study is the open label phase. During this phase you will be given the opportunity to try the active treatment. You will be sent enough capsules to last 6 weeks. You will be asked to complete health questionnaires in a similar manner to the RCT phase, and provide a 3rd and final urine sample. After the completion of the open label phase, you will be provided with details on how to obtain the nutrients in NZ, should you decide to continue with the supplementation.

Immediately after the open label phase, all participants will enter into the 12-month naturalistic follow up phase. This will allow us to record whether you continue using the supplements and to monitor your health and well-being over a longer period of time. You will be asked to complete various online health questionnaires at 3 months, 6 months and 12 months into this phase.

If you have any questions or concerns about your mental health or treatment for a mental health issue, please speak to your General Practitioner. Referrals to participate in the study can only be made via your GP.

Principal Investigator: Angela Sherwin

PhD student, Mental Health Research Laboratory at the University of Canterbury, New Zealand


  • Bachelor of Science, double major in Psychology and Biology, University of Canterbury, New Zealand.
  • BSc Hons in Psychology, University of Canterbury, New Zealand.

Angela is a mature student, having returned to study after a career in broadcast media. Angela’s interests lie in the biological underpinnings of psychological disorders. She lives in Canterbury with her partner and son, and in her spare times volunteers as a Youthline Counsellor.

Co-Investigator: Professor Julia Rucklidge

Registered Clinical Psychologist


  • Bachelor of Science (McGill University)
  • Master of Science (University of Calgary)
  • Doctor of Philosophy (University of Calgary)

Research interest/experience: Julia’s research interests are centered on the role of nutrition in the expression and treatment of mental illness, from ADHD to depression, to stress following natural disasters. Research methodologies include single case research designs, open label trials and randomised controlled trials. She also has clinical interest and experience in the areas of ADHD, child and adolescent clinical psychology, learning disabilities, youth offending, earthquake research, nutritional interventions, mood disorders.

Additional Research Team Members:

Professor Ian Shaw (Supervisor, University of Canterbury)

Professor Roger Mulder (Medical Supervisor, University of Otago)

A/Prof Joseph Boden (Statistical consultation)

How much does it cost?

There will be no fees or costs throughout the duration of the study.

The placebo and the active treatment are provided to you free of charge. The manufacturing company do not provide any financial support.

How do I take part?

If you’re interested in taking part, you first need to complete an online questionnaire to assess your eligibility. The questionnaire can be found on by clicking here and should take approximately 10 minutes to complete.

After completing the survey, an investigator will contact you regarding your eligibility to participate in the trial as well as send a letter to your General Practitioner for referral into the trial.

Contacting the trial researchers

Once admitted to the trial you will be given contact information for our researcher.

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