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The Effects of Vitamin B6 Supplementation on Pain Thresholds and Tolerance

Phase 1
Recruiting
Conditions
Pain
Interventions
Drug: Vitamin B6 100 MG
Other: Placebo
Registration Number
NCT06415383
Lead Sponsor
University of Reading
Brief Summary

This clinical trial aims to explore the effect of Vitamin B6 supplementation on pain thresholds and tolerance in healthy adults using thermal and electrical stimulation. Researchers will compare a placebo group to high-dose Vitamin-B6 to see if vitamin B6 increases pain thresholds and tolerance.

Detailed Description

The main questions it aims to answer are:

* How does vitamin B6 affect pain thresholds and tolerance following a single 100mg dose?

* How does vitamin B6 affect pain thresholds following daily supplementation for up to a month?

* Does vitamin B6 supplementation affect measures related to the experience of pain, such as state anxiety, sleep, diet, and mood at different time points

Recruitment & Eligibility

Status
RECRUITING
Sex
All
Target Recruitment
20
Inclusion Criteria
  • Over the age of 18 years
  • Fluent speaker of English language
Exclusion Criteria
  • Under 18 years
  • Presence or history of chronic pain
  • Presence of neuropathic/nerve pain
  • Raynaud's syndrome
  • Using any vitamin supplementations that contain Vitamin B6 at more than the RDA, or combinations of B vitamins.
  • On any medication that is GABA agonistic
  • Any use of analgesic/anti-inflammatory medication up to 48 hours prior to any of the testing sessions.
  • Any heart conditions
  • Newly acquired tattoos on the pain stimulation site

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Vitamin-B6Vitamin B6 100 MGParticipants will consume one high-dose Vitamin B6 100 mg tablet orally once daily for one month. Vitamin B6 will be provided as Pyridoxal-5'-Phosphate (PLP).
PlaceboPlaceboParticipants will consume a Placebo tablet matching the appearance of the Vitamin B6 tablets in the Experimental arm orally once daily for one month.
Primary Outcome Measures
NameTimeMethod
Cold immersion pain toleranceThis will be done at baseline, 3-5 days, 11-13, and 28-35 days after the start of the intervention

Pain tolerance will be measured by recording the number of seconds the participant is willing to keep their hand immersed in a 5 degree celsius cold bath, up to a maximum of 120 sec.

Electrical pain sensitivityThis will be done at baseline, 4-5 hours, 3-5 days, 11-13, and 28-35 days after the start of the intervention

Pain sensitivity will be measured using electrical stimulation. Starting at an initial intensity of 0.3 mA, the intensity of each subsequently applied electrical stimulus will be increased in steps of 0.3 mA each, with a maximum intensity of 10 mA. The procedure will be continued until the participant perceives the applied shock as moderately painful (equivalent to a pain rating of 5 out of 10 or higher). The procedure will be repeated three times. The average intensity (in mA) needed for participants to perceive a moderate pain sensation will be used as outcome measure. Low values will therefore indicate a high sensitivity to electrical stimulation, whereas high values will indicate a low pain sensitivity in response to electrical stimulation.

Thermal sensory thresholdThis will be done at baseline, 4-5 hours, 3-5 days, 11-13, and 28-35 days after the start of the intervention

Sensory threshold will be measured using thermal stimulation (heat stimulation). The starting temperature of the applied probe will be adjusted to the individual's skin temperature and then slowly increased (0.5 deg C/s) until the participant feels a slight warm sensation. For safety, the temperature will never exceed 50 deg C. The procedure will be repeated three times. The average change in temperature (in degree Celsius) needed for participants to perceive a warm sensation will be used as outcome measure. Low values will therefore indicate a high sensitivity to warmth, whereas high values will indicate a low warmth sensitivity.

Thermal pain toleranceThis will be done at baseline, 4-5 hours, 3-5 days, 11-13, and 28-35 days after the start of the intervention

Pain tolerance will be measured using thermal stimulation (heat stimulation). The starting temperature of the applied probe will be adjusted to the individual's skin temperature and then slowly increased (1 deg C/s) until the participant feels that they can't tolerate the heat anymore. For safety, the temperature will never exceed 50 deg C. The procedure will be repeated three times. The average change in temperature (in degree Celsius) needed for participants to reach their pain tolerance will be used as outcome measure. Low values will therefore indicate low pain tolerance, whereas high values will indicate high pain tolerance.

Pain wind-upThis will be done at baseline, 4-5 hours, 3-5 days, 11-13, and 28-35 days after the start of the intervention

Pain sensitisation will be measured using a wind-up paradigm (temporal summation) with thermal stimulation (heat simulation).

The thermal probe will start at 32 deg C and increase in temperature (100 deg C/s) to 49 deg C. After a duration of 800 ms, the temperature will return to baseline. Participants will be asked for a pain rating on a scale form 0 (not painful) to 10 (extremely painful). Subsequently, a series of 10 heat stimuli (identical to the once above, ISI 400 ms) will be applied. Participants will be asked to rate the most intense pain that they felt across the series, using the same 0-10 rating scale. The difference in pain ratings in response to the series and to the single stimulus will be used as the outcome measure. Higher (positive) ratings will indicate a stronger sensitisation to repeated painful stimuli. In contrast, negative values will indicate habituation to repeated painful stimuli.

Thermal pain thresholdThis will be done at baseline, 4-5 hours, 3-5 days, 11-13, and 28-35 days after the start of the intervention

Pain threshold will be measured using thermal stimulation (heat stimulation). The starting temperature of the applied probe will be adjusted to the individual's skin temperature and then slowly increased (1 deg C/s) until the participant feels a slight pain/burning sensation. For safety, the temperature will never exceed 50 deg C. The procedure will be repeated three times. The average change in temperature (in degree Celsius) needed for participants to perceive a slight pain/burning sensation will be used as outcome measure. Low values will therefore indicate high pain sensitivity, whereas high values will indicate low pain sensitivity.

Secondary Outcome Measures
NameTimeMethod
State anxietyThis will be done at baseline, 4-5 hours, 3-5 days, 11-13, and 28-35 days after the start of the intervention

State anxiety will be measured using the State-Trait Anxiety Inventory (STAI), which produces a minimum score of 20 and a maximum score of 80, where higher scores indicate greater anxiety.

Dietary intakeThis will be measured at baseline during their first visit only

Dietary intake will be measured using the Mediterranean Diet Adherence Screener(MEDAS), which produces a score ranging between 0 and 14, where higher scores indicate greater adherence to the Mediterranean diet.

Positive and negative affectThis will be done at baseline, 4-5 hours, 3-5 days, 11-13, and 28-35 days after the start of the intervention

State positive and negative affect will be measured using the The Positive And Negative Affect Schedule Now (PANAS-N) (PANAS-N; adapted from Watson et al., 1988).

Sleep qualityThis will be done at baseline, 3-5 days, 11-13, and 28-35 days after the start of the intervention

Sleep quality will be measured using the Pittsburgh Sleep Quality Index (PSQI), which results in a score ranging between 0 and 21, where higher scores indicate worse sleep quality.

Trial Locations

Locations (1)

University of Reading

🇬🇧

Reading, Berkshire, United Kingdom

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