Research has shown that there is a close relationship between sleep and diet. It has been shown that a vitamin and mineral rich diet is related to better sleep. This relationship can go both ways as poor sleep can also impact on your diet. Specifically, low magnesium levels have been associated with insomnia and adding magnesium to the diet of an individual with insomnia can help with their symptoms. Whilst this is known about insomnia, far less is known about the impact of magnesium on general sleep health. In other words, people who don't have a sleep disorder but could be sleeping better generally.

The aim of this study is to determine whether supplementing with Magnesium in those people who are deficient over a period of 8 weeks improves overall sleep health.

This study will be an open label trial 60 participants will consume 250mg of magnesium supplement daily over a 56-day period. During their participation in this study participants will visit the Sleep Lab on three (3) occasions to pick up or drop off an actiwatch and receive the supplement (visit 2).

Informed consent will be obtained online and be followed by an online demographic screener, sleep screener (SDSCL-25), chronotype screener (MCTQ, HO), standard health screener and 3-day food diary.

On visit 1 participants will receive an actiwatch and undergo a 7 night sleep monitoring period where remote assessment of sleep via Actigraphy watch will be completed (baseline).

On visit 2, 7-10 days following visit 1, participants will arrive at the lab return their actigraphy watch and be provided with a new actiwatch and the supplement. Participants will provide a detailed recall of their diet in the past 24 hours and complete a Gastrointestinal symptoms questionnaire - The questionnaire asks 11 questions, plus a 12th open-ended question, about gastrointestinal experiences, with 5 possible ratings: 'not at all' (score of 0), 'A little' (score of 1), 'a moderate amount' (score of 2), 'quite a lot' (score of 3) and 'a severe amount' (score of 4). Scores can range between 0-44 with a higher score indicating a more negative experience of symptoms.

On visit 3, 56 days following, visit 2, participants will return the actiwatch and any supplements left over then be debriefed and participant payment details will be taken to facilitate their participant payment (£50).

Note: Timings given here are approximates for illustrative purposes and may be subject to change due to unexpected delays.

Inclusion Criteria:

• Healthy male or female adult between the ages of 18 and 39 years of age.
• Have a stable sleep/wake schedule (bedtime between 9pm and 1am and wake time between 6am and 10am at least 5 nights per week)
• Are a fluent English speaker
• Diet which is low in magnesium
• Self-identify as a poor sleeper (i.e. poor sleep quality or unrefreshing sleep).

Exclusion Criteria:

• Have symptoms of COVID-19
• Display evidence of current or recent sleep disorders (e.g. sleep apnea, insomnia, circadian rhythm disorders); an initial screening for sleep disorders will be conducted using the Sleep Disorders Screening Checklist - 25 (SDS-CL). Have a history of seizures or epilepsy
• Have recently (within the last 12 weeks) had an infection and/or used antibiotic medication
• Are pregnant, seeking to become pregnant or lactating
• Are a shift worker or a recent history of shift work in the previous 6 months
• Are participating in other intervention research trials
• Have experienced travel across multiple time zones within the last three months or will be experiencing travel across multiple time zones during the study.
• Have recently been diagnosed and/or treated for a mental health or substance use disorder.
• Are currently unwell with anything that impacts sleep.
• Are taking any medication which has a sedative effect
• Are currently using medication which affects the central nervous system.
• Are currently misusing alcohol or drugs.