NCT01426490

The Effects of Vitamin B-6 Status on Homocysteine, Oxidative Stress, One-carbon Metabolism and Methylation: Cross-section, Case-control, Intervention and Follow-up Studies in Colorectal Cancer

• Status: Unknown
• Phase: Phase 2 / Phase 3
• Study type: Interventional
• Enrollment: 300 (estimated)
• Sponsor: Taichung Veterans General Hospital · Academic / Other
• Sex: All
• Age: 18 Years – 85 Years
• Healthy volunteers: Accepted

Summary

Vitamin B-6, folate and homocysteine may play a critical role in the colorectal cancer progression. This is a 4-y study and the specific aims are: 1) to compare vitamin B-6, folate and homocysteine status, oxidative stress, antioxidant activities and DNA methylation between subjects with colorectal polyps and colorectal cancer; 2) to study the effects of vitamin B-6, folate and homocysteine status on oxidative stress, antioxidant activities and DNA methylation in colorectal cancer patients; 3) to evaluate whether folic acid and/or pyridoxine supplementation had a beneficial effect on oxidative stress, antioxidant activities and DNA methylation in patients with colorectal; 4) to compare vitamin B-6, folate and homocysteine status, oxidative stress, antioxidant activities and DNA methylation between colorectal cancer patients and age-, sex-matched healthy subjects; 5) to evaluate the effect of vitamin B-6, folate and homocysteine status, oxidative stress, antioxidant activities and DNA methylation on the risk of colorectal cancer (odds ratio); 6) to follow the effects of vitamin B-6, folate and homocysteine status, oxidative stress, antioxidant activities and DNA methylation on the occurrence of colorectal cancer; 7) to follow the effects of pyridoxine and/or folic acid supplementation on the occurrence of colorectal cancer. This protocol is designed as a hospital-based cross-sectional, case-control, double blinded randomized placebo-controlled intervention and follow-up trial. Three hundred colorectal cancer patients and 300 age-, sex-matched controls who meet the inclusion criteria will be recruited from Taichung General Veterans Hospital. If cancer patients' plasma pyridoxal 5'-phosphate (PLP) level less than 30 nmol/L will be asked to participate the intervention study and will be blinded and randomly assigned to either the 1) control (vitamin C, 100 mg/d); 2) 50 mg vitamin B-6; 3) 400 microgram/d folic acid; or 4) vitamin B-6 (50 mg/d) plus folic acid (400 microgram/d) for 1 year. Data on demography, anthropometry, medical history, food frequency questionnaire and 24-h diet recall will be collected. Cancer patients will have fasting blood drawn before surgery or receiving chemotherapy. Additionally, fasting blood samples will be obtained at month 0, 3, 6, 9 and 12 during intervention period and at month 6, 12, 18, 24, 30, 36, 42 and 48 during follow-up. Hematological, plasma and erythrocyte PLP, plasma pyridoxal and 4-pyridoxic acid, serum and erythrocyte folate, serum vitamin B-12, homocysteine, SAM, SAH, lipid peroxidation indicators (TBARS, oxidized LDL), glutathione, antioxidant enzymatic activities and DNA methylation and MTHFR 677C\>T polymorphism will be measured.

Conditions

• Colorectal Cancer

Interventions

Type	Name	Description
DIETARY_SUPPLEMENT	Vitamin C	Vitamin C, 100 mg/d
DIETARY_SUPPLEMENT	Vitamin B6	Vitamin B6, 50mg/d
DIETARY_SUPPLEMENT	Folic acid	Folic acid 400 microgram/d
DIETARY_SUPPLEMENT	Vitamin B6 plus folic acid	Vitamin B6, 50 mg; folic acid, 400 microgram

Timeline

• Start date: 2011-08-01
• Primary completion: 2015-07-01
• Completion: 2015-07-01
• First posted: 2011-08-31
• Last updated: 2014-02-19

Locations

1 site across 1 country: Taiwan