An interventional study of Oral B-Complex Vitamin (B6, B9 and B12) and Placebo in Low Anterior Resection Syndrome, Hyperhomocysteinemia and Rectal Cancer, sponsored by Qilu Hospital of Shandong University. Not yet recruiting at 1 site in China. Open to participants aged 18 Years to 75 Years. Per ClinicalTrials.gov, last updated 2026-11-10.
Sponsored by Qilu Hospital of Shandong University · Not applicable, Interventional, and Prevention
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:
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:
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%.
82 studies on the registry are indexed under Low Anterior Resection Syndrome; 38 are open to participants now.
This study's planned enrollment of 277 is above the median of 72 across 56 interventional studies indexed under Low Anterior Resection Syndrome.
Browse Low Anterior Resection Syndrome studies →Qilu Hospital of Shandong University is the lead sponsor of 310 studies on the registry; 188 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Neoadjuvant treatment is given before the main treatment (usually surgery), often to shrink a tumour. Adjuvant treatment is given after it, to lower the chance of the cancer coming back.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Metastases
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Adjuvant and neoadjuvant
Neoadjuvant treatment is given before the main treatment (usually surgery), often to shrink a tumour. Adjuvant treatment is given after it, to lower the chance of the cancer coming back.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Dietary Supplement: Oral B-Complex Vitamin (B6, B9 and B12)
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.
Other: Placebo
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.
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.
Incidence of Low Anterior Resection Syndrome (LARS)
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).
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)
LARS Score
Total LARS score (range 0-42; higher scores indicate worse bowel function), compared between groups as a continuous variable.
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)
Serum Homocysteine Concentration
Serum homocysteine concentration (μmol/L).
Time frame: Baseline (preoperative), and 3 and 6 months after surgery
Systolic Blood Pressure
Systolic blood pressure (mmHg) measured in the seated position.
Time frame: 3 and 6 months after surgery
Diastolic Blood Pressure
Diastolic blood pressure (mmHg) measured in the seated position.
Time frame: 3 and 6 months after surgery
Anal Resting Pressure
Anal resting pressure (mmHg) measured by anorectal manometry.
Time frame: 3 and 6 months after surgery
Maximum Anal Squeeze Pressure
Maximum anal squeeze pressure (mmHg) measured by anorectal manometry.
Time frame: 3 and 6 months after surgery
Presence of Rectoanal Inhibitory Reflex
Proportion of participants with a present rectoanal inhibitory reflex on anorectal manometry.
Time frame: 3 and 6 months after surgery
Plan to share: No — 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.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Nov 2026. You cannot join it, but the record below documents what was studied.
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