Pain, AcuteVicamedNCT06306183
Effect of Vitamin C on Pain Reduction After an Emergency Department Visit
A study testing Vitamin C in people with Pain, Acute, run by Centre Integre Universitaire de Sante et Services Sociaux du Nord de l'ile de Montreal at 4 sites in Canada.
Trial summary
Musculoskeletal (MSK) injuries such as sprains, strains, bruises, and fractures are among the most common reasons people visit the emergency department. These injuries often cause significant pain in the first few days, making it difficult to move, work, or sleep. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Pain, Acute
- What is being tested?
- Vitamin C
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 204 participants
- Where
- 4 sitesCanada
- Study dates
- 1 Sep 2025to Dec 2029
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age ≥ 18 years old
- Presenting to the ED with acute MSK pain of ≤ 48 hours duration at triage
- Verbal numerical rating scale pain intensity at triage of ≥ 4 on a 0-10 scale
- Triaged to the ambulatory section of the ED
- Able to communicate in French or English
Who cannot join
- Usage of Vit C supplements in the last week
- Active cancer
- Treated with opioids for any pain within 24 hours prior to recruitment
- Treatment for chronic pain
- Unable to fill out a pain intensity diary or unavailable for follow-up
- Allergy to milk (lactose in the placebo) or Vit C
Show all 9Show fewer
- Treated with cyclosporine or warfarin
- Pre-existing oxalate nephropathy, liver cirrhosis or hemochromatosis
- Hospitalized after clinician evaluation
Trial locations and contacts
4 sites in 1 country. Contact the study team or a site near you to ask about taking part.
Canada4 sites, 4 recruiting
- Not yet recruiting
Hôtel-Dieu de Lévis
Lévis, Quebec, G6V 3Z1
Emilie Coté, BSc, 418-835-7121, Emilie.Cote.cisssca@ssss.gouv.qc.ca
Patrick Archambault, MD MSc
- Recruiting
Hopital du Sacre-Coeur de Montreal
Montreal, Quebec, H4J 1C5
Martin Marquis, MSc, 514-338-2222 ext. 7584, martin.marquis@crhsc.rtss.qc.ca
Chantal Lanthier, RN, 514-338-2222 ext. 3318, chantal.lanthier@crhsc.rtss.qc.ca
- Not yet recruiting
The Ottawa Hospital - General and Civic Campus
Ottawa, Ontario, K1Y 1J8
Gabriel Sandino-Gold, BSc, 613-798-5555 ext. 17709, gsandino@ohri.ca
- Not yet recruiting
CHU de Québec - Université Laval
Québec, Quebec
Ariane Bluteau, MSc, 418 525-4444 ext. 70542, ariane.bluteau@crchudequebec.ulaval.ca
About this study
Official title: Vitamin C for Acute Musculoskeletal Pain in Emergency Department Patients: A Triple-Blind Randomized Control Trial (VICAMED)
Musculoskeletal (MSK) injuries such as sprains, strains, bruises, and fractures are among the most common reasons people visit the emergency department. These injuries often cause significant pain in the first few days, making it difficult to move, work, or sleep. Usual pain medications like ibuprofen or acetaminophen can help, but they are not safe or effective for everyone. Some people cannot take them because of heart, kidney, stomach, or liver problems. Others still experience strong pain despite treatment. Because of these limits, some patients receive opioids, which can cause side effects and carry a risk of dependence. Safer and more accessible options are needed.
Vitamin C is widely known for supporting the immune system, but research suggests it may also help reduce pain and inflammation. Studies in surgical patients have shown that vitamin C can lower pain levels, reduce the need for opioids, and support healing. These effects may be linked to its antioxidant properties and its role in tissue repair. However, no study has tested whether vitamin C can help people with recent MSK injuries treated in the emergency department.
Read more
The VICAMED study aims to answer this question. Adults arriving with an MSK injury that occurred within the past 48 hours can participate if they have at least moderate pain. Participants are randomly assigned to receive either vitamin C or a placebo. The first dose is given in the emergency department, followed by twice daily capsules for three days. Pain is measured using a simple 0-100 scale, recorded in an electronic or paper diary. A follow-up on day six helps the research team understand each participant's recovery, medication use, and overall experience.
Vitamin C is inexpensive, widely available, and very safe at the doses used in this study. If it proves effective, it could offer a simple, low risk option to help patients manage pain after an MSK injury and reduce the need for opioids in emergency care.
Read the detailed description
Background:
Acute musculoskeletal (MSK) injuries are a major cause of emergency department (ED) visits and frequently result in moderate to severe pain during the first days following presentation. First-line analgesics such as NSAIDs and acetaminophen have important contraindications and safety limitations, particularly in older adults and patients with comorbidities, underscoring the need for safe, accessible, opioid-sparing alternatives. Preclinical studies and postoperative trials suggest that vitamin C (ascorbic acid) may provide analgesic and anti-inflammatory effects through reduction of oxidative stress, protection of neural tissues, and enhanced collagen synthesis. Meta-analyses have reported reductions in postoperative opioid consumption, pain intensity, and inflammatory markers. However, no randomized controlled trial has evaluated vitamin C for acute traumatic MSK pain in the ED.
Objective:
The primary objective is to determine whether a single 900 mg oral dose of vitamin C reduces pain intensity one hour after administration compared with placebo in adults presenting with acute MSK injuries. The main secondary objective is to assess whether 900 mg of vitamin C taken twice daily for three days reduces the time-weighted sum of pain-intensity difference (SPID) over 72 hours.
Methods:
The VICAMED study is a multicentre, triple-blind, randomized, placebo-controlled trial conducted in three university-affiliated EDs in Canada. Eligible participants are adults aged ≥18 years with MSK pain ≤48 hours, triaged to ambulatory care, and reporting pain >3/10. Exclusion criteria include recent vitamin C use, active cancer, recent analgesic intake, chronic pain treatment, and contraindications such as oxalate nephropathy or interactions with cyclosporine or warfarin. Participants receive an initial 900 mg dose of vitamin C or placebo in the ED, followed by twice-daily dosing for three days. Pain intensity is measured using validated 0-100 visual analog scales through electronic or paper diaries. A structured day-six follow-up captures missing data, analgesic use, adverse events, and health-related quality of life (EQ-5D-5L). The primary analysis uses ANCOVA adjusting for site and fracture status. Secondary analyses evaluate SPID72, analgesic consumption, time to significant pain relief, time to pain-free, proportion of days with adequate relief, adverse events, and healthcare utilization.
Based on a minimal clinically important difference of 13 points on a 0-100 pain scale and prior variance estimates, 204 participants are required for the primary outcome. The sample size for SPID72 will be finalized using pilot study data currently being analyzed. The study is powered to detect clinically meaningful differences in both immediate and short-term pain trajectories.
Expected Results:
If vitamin C demonstrates analgesic efficacy in acute MSK injuries, it could represent a safe, inexpensive, widely accessible, and opioid-sparing therapeutic option for ED patients, including those unable to use NSAIDs or acetaminophen. Given its favourable safety profile and over-the-counter availability, vitamin C has strong potential for rapid clinical integration. The research team's established collaborations within national emergency medicine networks will support broad dissemination and facilitate implementation across Canadian EDs.
- Conditions
- Pain, Acute
- Being tested
- Vitamin C, Placebo
- Keywords
- Vitamin C, NSAID, Emergency department, Pain, RCT
- Medical subject headings
- Acute Pain, Emergencies, Pain
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Vitamin CDietary supplement
900 mg vitamin C taken orally twice a day (one in the morning and one in the evening) for a 3-day period after ED discharge for the treatment arm.
PlaceboOther
Placebo taken orally twice a day (one in the morning and one in the evening) for a 3-day period after ED discharge for the treatment arm.
| Study group | Role | What they receive |
|---|---|---|
| Vitamin C | Experimental | 900 mg vitamin C taken orally twice a day Receives: Dietary Supplement: Vitamin C |
| Placebo | Placebo comparator | Placebo taken orally twice a day Receives: Other: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Time-weighted sum of the pain-intensity difference (SPID)
The primary outcome is the time-weighted sum of the pain-intensity difference (SPID) over the three-day treatment period on a 0-100 visual analog scale (VAS), where 0 is no pain and 100 the worst pain imaginable. The SPID accounts for both the magnitude of the pain change and its duration, producing a single value that reflects the patient's overall experience.
Measured: Three days
Secondary outcomes (9)
Difference in pain intensity
The main secondary outcome is the difference in pain intensity, also measured on a 0-100 visual analog scale (VAS), where 0 is no pain and 100 the worst pain imaginable, between groups one hour after taking the first study drug in the ED.
Measured: Three days
Consumption of as-needed pain medication
Participants will be asked the name and the total amount of pain medication taken during the three-day follow-up.
Measured: Three days
Time for significant pain relief
Time for significant pain relief, reported in hours, is define in a 50% reduction in pain intensity.
Measured: Six days
Time to pain-free
Time, reported in hours, when pain reach 0 on a 0-100 visual analog scale (VAS), where 0 is no pain and 100 the worst pain imaginable
Measured: Six days
Percentage of days with adequate relief
To assess the proportion of days with adequate pain control, participants will answer a daily yes/no question regarding whether their pain was adequately relieved.
Measured: Six days
New analgesic prescriptions
Numbered and of new pain medication prescription received during follow-up, even opioids.
Measured: Three days
Adverse events
We will document during the day-six questionnaire if any of the following adverse events were experienced during the three-day period: nausea, vomiting, constipation, dizziness, drowsiness, sweating, weakness, or other adverse events.
Measured: Three days
Quality of life improvement at six days
Health-related quality of life will be assessed using the validated EQ-5D-5L questionnaire.
EuroQol - five dimensions - 5 levels.
It assesses five dimensions (mobility, self-care, usual activities, pain/discomfort, and anxiety/depression) across 5 levels of severity-from no problems to extreme problems-providing a 5-digit health state profile used in clinical research and economic evaluations.
Common Interpretation:
11111: Perfect health (Index 1.0). 55555: Worst health (lowest possible index).
Measured: Six days
Quantity of Healthcare visits
Participants will be asked about the number of all unscheduled or scheduled healthcare visits related to their initial pain condition during the day-6 questionnaire.
Measured: Six days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 Mar 2024
- Study start1 Sep 2025
- Primary completionDec 2028 (estimated)
- Study completionDec 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Pain, AcuteStudies 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 N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Triple-blind randomized placebo-controlled trial
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Investigator
- Enrolment
- 204 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Centre Integre Universitaire de Sante et Services Sociaux du Nord de l'ile de Montreal
- Sponsor type
- University, hospital or other
- Collaborators
- Hopital de l'Enfant-Jesus, The Ottawa Hospital
- Responsible party
- Principal investigator, Raoul Daoust, Centre Integre Universitaire de Sante et Services Sociaux du Nord de l'ile de Montreal
- Investigators
- Raoul Daoust, MD MSc, Principal investigator, Université de Montréal
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06306183
- Sponsor's protocol ID
- 2024-2829
- Acronym
- Vicamed
- Status last verified
- Feb 2026
- First submitted
- 28 Feb 2024
- Last updated
- 2 Mar 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided: IPD could be shared upon request, upon approval by our institution.
Study at a glance
From the registry record, last updated by the sponsor on 2 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Vitamin C for Acute Musculoskeletal Pain in Emergency Department Patients: A Triple-Blind Randomized Control Trial (VICAMED)
- ClinicalTrials.gov ID
- NCT06306183
- Acronym / sponsor ID
- Vicamed / 2024-2829
- Conditions
- Pain, Acute
- Keywords
- Vitamin C, NSAID, Emergency department, Pain, RCT
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 204 participants (estimated)
- Lead sponsor
- Centre Integre Universitaire de Sante et Services Sociaux du Nord de l'ile de MontrealUniversity, hospital or other
- Collaborators
- Hopital de l'Enfant-Jesus, The Ottawa Hospital
- Study start
- 1 Sep 2025 (actual)
- Primary completion
- Dec 2028 (estimated)
- Study completion
- Dec 2029 (estimated)
- First posted
- 12 Mar 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.
Musculoskeletal (MSK) injuries such as sprains, strains, bruises, and fractures are among the most common reasons people visit the emergency department. These injuries often cause significant pain in the first few days, making it difficult to move, work, or sleep. Usual pain medications like ibuprofen or acetaminophen can help, but they are not safe or effective for everyone. Some people cannot take them because of heart, kidney, stomach, or liver problems. Others still experience strong pain despite treatment. Because of these limits, some patients receive opioids, which can cause side effects and carry a risk of dependence. Safer and more accessible options are needed.
Vitamin C is widely known for supporting the immune system, but research suggests it may also help reduce pain and inflammation. Studies in surgical patients have shown that vitamin C can lower pain levels, reduce the need for opioids, and support healing. These effects may be linked to its antioxidant properties and its role in tissue repair. However, no study has tested whether vitamin C can help people with recent MSK injuries treated in the emergency department.
The VICAMED study aims to answer this question. Adults arriving with an MSK injury that occurred within the past 48 hours can participate if they have at least moderate pain. Participants are randomly assigned to receive either vitamin C or a placebo. The first dose is given in the emergency department, followed by twice daily capsules for three days. Pain is measured using a simple 0-100 scale, recorded in an electronic or paper diary. A follow-up on day six helps the research team understand each participant's recovery, medication use, and overall experience.
Vitamin C is inexpensive, widely available, and very safe at the doses used in this study. If it proves effective, it could offer a simple, low risk option to help patients manage pain after an MSK injury and reduce the need for opioids in emergency care.
Detailed description
Background:
Acute musculoskeletal (MSK) injuries are a major cause of emergency department (ED) visits and frequently result in moderate to severe pain during the first days following presentation. First-line analgesics such as NSAIDs and acetaminophen have important contraindications and safety limitations, particularly in older adults and patients with comorbidities, underscoring the need for safe, accessible, opioid-sparing alternatives. Preclinical studies and postoperative trials suggest that vitamin C (ascorbic acid) may provide analgesic and anti-inflammatory effects through reduction of oxidative stress, protection of neural tissues, and enhanced collagen synthesis. Meta-analyses have reported reductions in postoperative opioid consumption, pain intensity, and inflammatory markers. However, no randomized controlled trial has evaluated vitamin C for acute traumatic MSK pain in the ED.
Objective:
The primary objective is to determine whether a single 900 mg oral dose of vitamin C reduces pain intensity one hour after administration compared with placebo in adults presenting with acute MSK injuries. The main secondary objective is to assess whether 900 mg of vitamin C taken twice daily for three days reduces the time-weighted sum of pain-intensity difference (SPID) over 72 hours.
Methods:
The VICAMED study is a multicentre, triple-blind, randomized, placebo-controlled trial conducted in three university-affiliated EDs in Canada. Eligible participants are adults aged ≥18 years with MSK pain ≤48 hours, triaged to ambulatory care, and reporting pain >3/10. Exclusion criteria include recent vitamin C use, active cancer, recent analgesic intake, chronic pain treatment, and contraindications such as oxalate nephropathy or interactions with cyclosporine or warfarin. Participants receive an initial 900 mg dose of vitamin C or placebo in the ED, followed by twice-daily dosing for three days. Pain intensity is measured using validated 0-100 visual analog scales through electronic or paper diaries. A structured day-six follow-up captures missing data, analgesic use, adverse events, and health-related quality of life (EQ-5D-5L). The primary analysis uses ANCOVA adjusting for site and fracture status. Secondary analyses evaluate SPID72, analgesic consumption, time to significant pain relief, time to pain-free, proportion of days with adequate relief, adverse events, and healthcare utilization.
Based on a minimal clinically important difference of 13 points on a 0-100 pain scale and prior variance estimates, 204 participants are required for the primary outcome. The sample size for SPID72 will be finalized using pilot study data currently being analyzed. The study is powered to detect clinically meaningful differences in both immediate and short-term pain trajectories.
Expected Results:
If vitamin C demonstrates analgesic efficacy in acute MSK injuries, it could represent a safe, inexpensive, widely accessible, and opioid-sparing therapeutic option for ED patients, including those unable to use NSAIDs or acetaminophen. Given its favourable safety profile and over-the-counter availability, vitamin C has strong potential for rapid clinical integration. The research team's established collaborations within national emergency medicine networks will support broad dissemination and facilitate implementation across Canadian EDs.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, care provider, investigator)
- Number of arms
- 2
- Model description
- Triple-blind randomized placebo-controlled trial
| Arm | Type | Receives |
|---|---|---|
| Vitamin C | Experimental | Dietary Supplement: Vitamin C900 mg vitamin C taken orally twice a day |
| Placebo | Placebo comparator | Other: PlaceboPlacebo taken orally twice a day |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Age ≥ 18 years old
- Presenting to the ED with acute MSK pain of ≤ 48 hours duration at triage
- Verbal numerical rating scale pain intensity at triage of ≥ 4 on a 0-10 scale
- Triaged to the ambulatory section of the ED
- Able to communicate in French or English
Key exclusion criteria (9 listed)
- Usage of Vit C supplements in the last week
- Active cancer
- Treated with opioids for any pain within 24 hours prior to recruitment
- Treatment for chronic pain
- Unable to fill out a pain intensity diary or unavailable for follow-up
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 C900 mg vitamin C taken orally twice a day (one in the morning and one in the evening) for a 3-day period after ED discharge for the treatment arm. | Dietary supplement | Vitamin C |
| PlaceboPlacebo taken orally twice a day (one in the morning and one in the evening) for a 3-day period after ED discharge for the treatment arm. | Other | Placebo |
Primary outcome
Time-weighted sum of the pain-intensity difference (SPID)
Time frame: Three days
The primary outcome is the time-weighted sum of the pain-intensity difference (SPID) over the three-day treatment period on a 0-100 visual analog scale (VAS), where 0 is no pain and 100 the worst pain imaginable. The SPID accounts for both the magnitude of the pain change and its duration, producing a single value that reflects the patient's overall experience.
9 secondary outcomes
Difference in pain intensity
Time frame: Three days
Consumption of as-needed pain medication
Time frame: Three days
Time for significant pain relief
Time frame: Six days
Time to pain-free
Time frame: Six days
Percentage of days with adequate relief
Time frame: Six days
New analgesic prescriptions
Time frame: Three days
Adverse events
Time frame: Three days
Quality of life improvement at six days
Time frame: Six days
Quantity of Healthcare visits
Time frame: Six days
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Mar 2026.
- Individual participant dataSharing planned: Undecided. IPD could be shared upon request, upon approval by our institution.
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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.
Raoul Daoust, MD MSc principal investigator
Université de Montréal
4 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Vitamin C in people with Pain, Acute, run by Centre Integre Universitaire de Sante et Services Sociaux du Nord de l'ile de Montreal at 4 sites in Canada.
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 5 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: looking for participants now, as of the sponsor's last update on 2 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 4 sites in Canada. 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.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Martin Marquis, MSc (514-338-2222, martin.marquis.cnmtl@ssss.gouv.qc.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Time-weighted sum of the pain-intensity difference (SPID) (time frame: Three days). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 2 Mar 2026.