PainPhase 1NCT06415383
The Effects of Vitamin B6 Supplementation on Pain Thresholds and Tolerance
A Phase 1 study testing Vitamin B6 100 MG in people with Pain, run by University of Reading at 1 site in United Kingdom.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Pain
- What is being tested?
- Vitamin B6 100 MG
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 43 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 30 May 2024to 30 Jun 2025
- Phase
- Phase 1
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Over the age of 18 years
- Fluent speaker of English language
Who cannot join
- 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
Show all 9Show fewer
- 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
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Testing the Effects of High-dose Vitamin B6 Supplements on Pain Thresholds and Tolerance in Healthy Adults
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.
Read the 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
- Conditions
- Pain
- Being tested
- Vitamin B6 100 MG, Placebo
- Keywords
- Vitamin B6, GABA, Excitation-Inhibition balance
- Medical subject headings
- Pain
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Vitamin B6 100 MGDrug
Vitamin B6 in for the form of pyridoxal phosphate (PLP)
PlaceboOther
Placebo tablet containing microcrystalline cellulose
| Study group | Role | What they receive |
|---|---|---|
| Vitamin-B6 | Experimental | Participants 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). Receives: Drug: Vitamin B6 100 MG |
| Placebo | Placebo comparator | Participants will consume a Placebo tablet matching the appearance of the Vitamin B6 tablets in the Experimental arm orally once daily for one month. Receives: Other: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Thermal sensory threshold
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.
Measured: This will be done at baseline, 4-5 hours, 3-5 days, 11-13, and 28-35 days after the start of the intervention
Thermal pain threshold
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.
Measured: This will be done at baseline, 4-5 hours, 3-5 days, 11-13, and 28-35 days after the start of the intervention
Electrical pain sensitivity
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.
Measured: This will be done at baseline, 4-5 hours, 3-5 days, 11-13, and 28-35 days after the start of the intervention
Thermal pain tolerance
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.
Measured: This will be done at baseline, 4-5 hours, 3-5 days, 11-13, and 28-35 days after the start of the intervention
Cold immersion pain tolerance
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.
Measured: This will be done at baseline, 3-5 days, 11-13, and 28-35 days after the start of the intervention
Pain wind-up
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.
Measured: This will be done at baseline, 4-5 hours, 3-5 days, 11-13, and 28-35 days after the start of the intervention
Secondary outcomes (4)
State anxiety
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.
Measured: This will be done at baseline, 4-5 hours, 3-5 days, 11-13, and 28-35 days after the start of the intervention
Positive and negative affect
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).
Measured: This will be done at baseline, 4-5 hours, 3-5 days, 11-13, and 28-35 days after the start of the intervention
Sleep quality
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.
Measured: This will be done at baseline, 3-5 days, 11-13, and 28-35 days after the start of the intervention
Dietary intake
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.
Measured: This will be measured at baseline during their first visit only
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 May 2024
- Study start30 May 2024
- Primary completion1 Mar 2025
- Study completion30 Jun 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (4)Papers the sponsor has linked to this study.
- Other trials for PainStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 43 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Reading
- Sponsor type
- University, hospital or other
- Collaborators
- INNOPURE
- Responsible party
- Principal investigator, David Field, University of Reading
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06415383
- Sponsor's protocol ID
- UREC24/13
- Status last verified
- Mar 2026
- First submitted
- 10 May 2024
- Last updated
- 11 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Spielberger, C. D., Gonzalez-Reigosa, F., Martinez-Urrutia, A., Natalicio, L. F., & Natalicio, D. S. (1971). The state-trait anxiety inventory. Revista Interamericana de Psicologia/Interamerican journal of psychology, 5(3 & 4).
Watson D, Clark LA, Tellegen A. Development and validation of brief measures of positive and negative affect: the PANAS scales. J Pers Soc Psychol. 1988 Jun;54(6):1063-70. doi: 10.1037//0022-3514.54.6.1063.
PubMed 3397865Buysse DJ, Reynolds CF 3rd, Monk TH, Berman SR, Kupfer DJ. The Pittsburgh Sleep Quality Index: a new instrument for psychiatric practice and research. Psychiatry Res. 1989 May;28(2):193-213. doi: 10.1016/0165-1781(89)90047-4.
PubMed 2748771Martinez-Gonzalez MA, Garcia-Arellano A, Toledo E, Salas-Salvado J, Buil-Cosiales P, Corella D, Covas MI, Schroder H, Aros F, Gomez-Gracia E, Fiol M, Ruiz-Gutierrez V, Lapetra J, Lamuela-Raventos RM, Serra-Majem L, Pinto X, Munoz MA, Warnberg J, Ros E, Estruch R; PREDIMED Study Investigators. A 14-item Mediterranean diet assessment tool and obesity indexes among high-risk subjects: the PREDIMED trial. PLoS One. 2012;7(8):e43134. doi: 10.1371/journal.pone.0043134. Epub 2012 Aug 14.
PubMed 22905215
Study at a glance
From the registry record, last updated by the sponsor on 11 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Testing the Effects of High-dose Vitamin B6 Supplements on Pain Thresholds and Tolerance in Healthy Adults
- ClinicalTrials.gov ID
- NCT06415383
- Acronym / sponsor ID
- UREC24/13
- Conditions
- Pain
- Keywords
- Vitamin B6, GABA, Excitation-Inhibition balance
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 43 participants (actual)
- Lead sponsor
- University of ReadingUniversity, hospital or other
- Collaborators
- INNOPURE
- Study start
- 30 May 2024 (actual)
- Primary completion
- 1 Mar 2025 (actual)
- Study completion
- 30 Jun 2025 (actual)
- First posted
- 16 May 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Vitamin-B6 | Experimental | Drug: Vitamin 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). |
| Placebo | Placebo comparator | Other: PlaceboParticipants will consume a Placebo tablet matching the appearance of the Vitamin B6 tablets in the Experimental arm orally once daily for one month. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- Over the age of 18 years
- Fluent speaker of English language
Key exclusion criteria (9 listed)
- 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Vitamin B6 100 MGVitamin B6 in for the form of pyridoxal phosphate (PLP) | Drug | Vitamin-B6 |
| PlaceboPlacebo tablet containing microcrystalline cellulose | Other | Placebo |
Primary outcome
Thermal sensory threshold
Time frame: This 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 threshold
Time frame: This 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.
Electrical pain sensitivity
Time frame: This 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 pain tolerance
Time frame: This 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.
Cold immersion pain tolerance
Time frame: This 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.
Pain wind-up
Time frame: This 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.
4 secondary outcomes
State anxiety
Time frame: This will be done at baseline, 4-5 hours, 3-5 days, 11-13, and 28-35 days after the start of the intervention
Positive and negative affect
Time frame: This will be done at baseline, 4-5 hours, 3-5 days, 11-13, and 28-35 days after the start of the intervention
Sleep quality
Time frame: This will be done at baseline, 3-5 days, 11-13, and 28-35 days after the start of the intervention
Dietary intake
Time frame: This will be measured at baseline during their first visit only
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Mar 2026.
- BackgroundSpielberger, C. D., Gonzalez-Reigosa, F., Martinez-Urrutia, A., Natalicio, L. F., & Natalicio, D. S. (1971). The state-trait anxiety inventory. Revista Interamericana de Psicologia/Interamerican journal of psychology, 5(3 & 4).
- Background: PubMed 3397865Watson D, Clark LA, Tellegen A. Development and validation of brief measures of positive and negative affect: the PANAS scales. J Pers Soc Psychol. 1988 Jun;54(6):1063-70. doi: 10.1037//0022-3514.54.6.1063.
- Background: PubMed 2748771Buysse DJ, Reynolds CF 3rd, Monk TH, Berman SR, Kupfer DJ. The Pittsburgh Sleep Quality Index: a new instrument for psychiatric practice and research. Psychiatry Res. 1989 May;28(2):193-213. doi: 10.1016/0165-1781(89)90047-4.
- Background: PubMed 22905215Martinez-Gonzalez MA, Garcia-Arellano A, Toledo E, Salas-Salvado J, Buil-Cosiales P, Corella D, Covas MI, Schroder H, Aros F, Gomez-Gracia E, Fiol M, Ruiz-Gutierrez V, Lapetra J, Lamuela-Raventos RM, Serra-Majem L, Pinto X, Munoz MA, Warnberg J, Ros E, Estruch R; PREDIMED Study Investigators. A 14-item Mediterranean diet assessment tool and obesity indexes among high-risk subjects: the PREDIMED trial. PLoS One. 2012;7(8):e43134. doi: 10.1371/journal.pone.0043134. Epub 2012 Aug 14.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing Vitamin B6 100 MG in people with Pain, run by University of Reading at 1 site in United Kingdom.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 11 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Thermal sensory threshold (time frame: This will be done at baseline, 4-5 hours, 3-5 days, 11-13, and 28-35 days after the start of the intervention). The study lists 6 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06415383, which also lists 4 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 11 Mar 2026.