Oral B-Complex Vitamin (B6, B9 and B12) Prevents Low Anterior Resection Syndrome in Rectal Cancer Patients With Hyperhomocysteinemia

November 4, 2026 updated by: Qilu Hospital of Shandong University

Oral B-Complex Vitamin (B6, B9 and B12) Supplementation for the Prevention of Low Anterior Resection Syndrome After Sphincter-Preserving Surgery in Rectal Cancer Patients With Hyperhomocysteinemia: A Randomized Controlled Trial

The goal of this clinical trial is to investigate if taking Oral B-Complex Vitamin (B6, B9 and B12) can help prevent low anterior resection syndrome (LARS) in rectal cancer patients with hyperhomocysteinemia after sphincter-preserving surgery for rectal cancer. LARS is a group of bowel problems that can occur after rectal cancer surgery, including frequent bowel movements, an urgent need to have a bowel movement, constipation, and loss of bowel control.

Our previous research suggests that hyperhomocysteinemia increased the occurrence of LARS. Folic acid, vitamin B6 and vitamin B12 are a safe, widely used way to treat hyperhomocysteinemia.

The main questions this study aims to answer are:

  • Does taking Oral B-Complex Vitamin (B6, B9 and B12) lower the rate of LARS 6 months after surgery?
  • How does this treatment affect internal anal sphincter (IAS) function?

Researchers will compare Oral B-Complex Vitamin (B6, B9 and B12) with a placebo (a look-alike tablet that contains no vitamins) to see if Oral B-Complex Vitamin (B6, B9 and B12) can help prevent LARS.

Participants will:

  • Take B-Complex Vitamin (B6, B9 and B12) every day for 6 months
  • Visit the clinic twice ( 3 months and 6 months after surgery) for checkups and tests
  • Complete the LARS score questionnaire 6 months after surgery

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Low anterior resection syndrome (LARS) is a cluster of bowel dysfunction symptoms after sphincter-preserving surgery for rectal cancer, including incontinence, urgency, and frequent bowel movements. The Chinese Expert Consensus on the Diagnosis and Treatment of LARS (2025 edition) reports an incidence of 69.8% at 3 months and 62.3% at 6-9 months after low anterior resection. LARS may persist for years and substantially impair quality of life. LARS is multifactorial, involving reduced rectal capacity and compliance, internal anal sphincter dysfunction and nerve injury. No drug or treatment is currently available to prevent LARS.

Hyperhomocysteinemia (HHcy) is defined as a serum homocysteine (Hcy) level above 15 μmol/L. The pooled prevalence of hyperhomocysteinemia (Hcy >15 μmol/L) in China was 25.9%. The prevalence of hyperhomocysteinemia is higher in cancer patients. Hyperhomocysteinemia increases the risk of various cardiovascular and cerebrovascular diseases, including coronary heart disease and stroke.

Our preliminary data showed that, in a single-center cohort of 530 patients who underwent low anterior resection for rectal cancer at Qilu Hospital of Shandong University between December 2023 and December 2025, hyperhomocysteinemia was present in 105 of 205 patients with LARS (51.2%) and in 95 of 325 patients without LARS (29.2%). This suggests hyperhomocysteinemia may be a risk factor of LARS.

In a Sprague-Dawley rat model of low anterior resection, hyperhomocysteinemia shortened colonic transit time and increased fecal water content. Postoperative supplementation with folic acid, vitamin B6 and vitamin B12 lowered serum Hcy and reversed these changes.

In our prospective single-arm pilot study, 80 patients who met the same eligibility criteria received Oral B-Complex Vitamin treatment. No adverse events were observed. After 6 months, majority of patients' Hcy levels returned to normal. LARS occurrence was much lower than 62.3%.

Study Type

Interventional

Enrollment (Estimated)

277

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

  • Name: Hao Wu, MD, PhD
  • Phone Number: +86 18560086947

Study Locations

    • Shandong
      • Jinan, Shandong, China, 250012
        • Qilu Hospital of Shandong University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 75 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Aged 18 to 75 years
  • Body mass index (BMI) of 18.5 to 28 kg/m2
  • Low anterior resection performed for rectal cancer
  • Serum homocysteine level between 15 and 50 μmol/L both before and after surgery
  • No evidence of tumor recurrence or distant metastasis
  • No short-term postoperative complications at the time of enrollment
  • Able to resume oral intake after surgery
  • Signed written informed consent

Exclusion Criteria:

  • History of, or planned, neoadjuvant or adjuvant radiotherapy or chemotherapy
  • Other severe chronic diseases, such as cardiovascular or cerebrovascular disease, diabetes mellitus or chronic respiratory disease
  • Renal insufficiency, epilepsy, or other gastrointestinal diseases
  • Hyperhomocysteinemia caused by inherited defects, such as cystathionine beta-synthase deficiency, methylenetetrahydrofolate reductase (MTHFR) deficiency or hereditary folate malabsorption, screened by detailed medical and family history; highly suspected cases will be referred for specialist diagnosis and excluded
  • Participation in any other clinical study within the past 3 months

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Oral B-Complex Vitamin (B6, B9 and B12)

Participants will take Oral B-Complex Vitamin (B6, B9 and B12) tablets, one tablet orally twice daily, starting after resumption of oral intake following surgery. Serum homocysteine (Hcy) will be measured at 3 months after surgery: if Hcy remains above 15 μmol/L, the full dose will continue for another 3 months; if Hcy has returned to normal, the dose will be reduced to one tablet once daily.Treatment will continue until the 6-month postoperative visit.

Film-coated oral tablet (0.3 g) registered as a health food in China (filing No. G201937000905), manufactured by Dongying Guangyuan Biotechnology Co., Ltd. Each tablet contains vitamin B6 (pyridoxine hydrochloride) 1.38 mg, folic acid (vitamin B9) 286 μg and vitamin B12 (cyanocobalamin) 3.05 μg. Excipients include corn starch, maltodextrin, microcrystalline cellulose, silicon dioxide, magnesium stearate, calcium carbonate and a film-coating premix.

Placebo Comparator: Placebo

Participants will take placebo tablets identical in appearance, color, odor and packaging to the Oral B-Complex Vitamin (B6, B9 and B12) tablets, one tablet orally twice daily, starting after resumption of oral intake following surgery. The same homocysteine-based dose-adjustment rules as in the experimental arm will apply, and treatment will continue until the 6-month postoperative visit.

Oral placebo tablet (0.3 g) containing corn starch and maltodextrin, with no active vitamins, manufactured by Dongying Guangyuan Biotechnology Co., Ltd. under good manufacturing practice. The placebo tablets are identical in appearance, color, odor and packaging to the Oral B-Complex Vitamin (B6, B9 and B12) tablets.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Incidence of Low Anterior Resection Syndrome (LARS)
Time Frame: 6 months after surgery (3 months after stoma closure for participants whose protective stoma has not been closed by 6 months after surgery)

Proportion of participants with LARS, defined as a total score of 21 or higher on the LARS score questionnaire. The LARS score is a validated 5-item questionnaire on bowel function (Emmertsen and Laurberg, 2012), with a total score ranging from 0 to 42; higher scores indicate worse bowel function (0-20: no LARS; 21-29: minor LARS; 30-42: major LARS).

6 months after surgery (3 months after stoma closure for participants whose protective stoma has not been closed by 6 months after surgery)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
LARS Score
Time Frame: 6 months after surgery (3 months after stoma closure for participants whose protective stoma has not been closed by 6 months after surgery)

Total LARS score (range 0-42; higher scores indicate worse bowel function), compared between groups as a continuous variable.

6 months after surgery (3 months after stoma closure for participants whose protective stoma has not been closed by 6 months after surgery)
Serum Homocysteine Concentration
Time Frame: Baseline (preoperative), and 3 and 6 months after surgery

Serum homocysteine concentration (μmol/L).

Baseline (preoperative), and 3 and 6 months after surgery
Systolic Blood Pressure
Time Frame: 3 and 6 months after surgery

Systolic blood pressure (mmHg) measured in the seated position.

3 and 6 months after surgery
Diastolic Blood Pressure
Time Frame: 3 and 6 months after surgery

Diastolic blood pressure (mmHg) measured in the seated position.

3 and 6 months after surgery
Anal Resting Pressure
Time Frame: 3 and 6 months after surgery

Anal resting pressure (mmHg) measured by anorectal manometry.

3 and 6 months after surgery
Maximum Anal Squeeze Pressure
Time Frame: 3 and 6 months after surgery

Maximum anal squeeze pressure (mmHg) measured by anorectal manometry.

3 and 6 months after surgery
Presence of Rectoanal Inhibitory Reflex
Time Frame: 3 and 6 months after surgery

Proportion of participants with a present rectoanal inhibitory reflex on anorectal manometry.

3 and 6 months after surgery

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Investigators

  • Principal Investigator: Wei Guo, MD, PhD, Qilu Hospital of Shandong University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

December 1, 2026

Primary Completion (Estimated)

December 1, 2027

Study Completion (Estimated)

December 1, 2027

Study Registration Dates

First Submitted

November 4, 2026

First Submitted That Met QC Criteria

November 4, 2026

First Posted (Actual)

November 10, 2026

Study Record Updates

Last Update Posted (Actual)

November 10, 2026

Last Update Submitted That Met QC Criteria

November 4, 2026

Last Verified

November 1, 2026

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data are subject to China's Regulations on the Management of Human Genetic Resources and will not be shared publicly. De-identified data supporting the published results may be made available upon reasonable request to the principal investigator, subject to approval by Qilu Hospital of Shandong University and compliance with applicable Chinese regulations.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

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