Clinical trial · Observational
NORVIT and WENBIT - Long-term Follow-up
Combined Analyses and Long-term Follow-up in the Two Norwegian Homocysteine-Lowering B-Vitamin Trials NORVIT and WENBIT
- Source
- ClinicalTrials.gov
- Retrieved
- Sep 8, 2026
- Layer
- normalized (units and labels harmonized; values unchanged)
- Run
- ING-CLINICALTRIALS-20260908-000001
Summary
Brief summary (as posted)
Two large homocysteine-lowering B-vitamin intervention trials have been performed in Norway during the period 1998 to 2005, NORVIT and WENBIT. The main objective in these trials was to study the clinical effects of homocysteine-lowering therapy with folic acid and vitamin B12 in patients with established coronary artery disease. Follow-up was terminated for NORVIT on Marc 31st 2004 and for WENBIT October 5th 2005, and none of the two trials proved any protective effect of the B-vitamin intervention on cardiovascular outcomes. There is so far no data on possible long-term effects following years of such B-vitamin treatment. Thus, the main objective of the combinded NORVIT-WENBIT study will will be to evaluate the long-term effect of the B-vitamin intervention on incident life-style diseases including cardiovascular disease, diabetes, osteoporotic fractures and cancer. A secondary object will be the identification of risk phenotypes or genotypes, and if such risk associations are midified by the B-vitamin intervention
Conditions
Conditions (3)
Free-text conditions as registered, with the CancerIndex entity they were reconciled to and the match type.
| Condition (as posted) | Mapped entity | Match | Confidence |
|---|---|---|---|
| Cancer | Malignant Neoplasm | ALIAS | 0.90 |
| Cerebrovascular Stroke | — | UNRESOLVED | — |
| Myocardial Infarction | — | UNRESOLVED | — |
Interventions
Interventions (0)
Data not yet available
Design
Arms and outcomes
Arms (4)
- label
- 1
- description
- Participants in NORVIT and WENBIT allocated to daily oral treatment with folic acid 0.8 mg and vitamin B12 0.4 mg
- label
- 2
- description
- Participants in NORVIT and WENBIT allocated to daily oral treatment with folic acid 0.8 mg, vitamin B12 0.4 mg and B6 40 mg.
- label
- 3
- description
- Participants in NORVIT and WENBIT allocated to daily oral treatment with vitamin B6 40 mg.
- label
- 4
- description
- Participants in NORVIT and WENBIT allocated to daily oral treatment with placebo
Primary outcomes (1)
- measure
- Possible effects of B-vitamin treatment on risk of developing cancer during the trial periods (completed by 2004 and 2005) and during post-trial follow-up.
Eligibility
Eligibility (as posted)
- Sex
- All
- Minimum age
- 27 Years
- Maximum age
- 86 Years
Show eligibility criteria text
Inclusion Criteria: * Randomised in the Norwegian Vitamin Trial (NORVIT) or in the Western Norway B-Vitamin Intervention Trial (WENBIT) Exclusion Criteria: * Withdrawn consent to participate in study cohort for post-trial observational follow-up
References
Publications (14)
- BACKGROUNDBonaa KH, Njolstad I, Ueland PM, Schirmer H, Tverdal A, Steigen T, Wang H, Nordrehaug JE, Arnesen E, Rasmussen K; NORVIT Trial Investigators. Homocysteine lowering and cardiovascular events after acute myocardial infarction. N Engl J Med. 2006 Apr 13;354(15):1578-88. doi: 10.1056/NEJMoa055227. Epub 2006 Mar 12. PMID 16531614
- BACKGROUNDBazzano LA, Reynolds K, Holder KN, He J. Effect of folic acid supplementation on risk of cardiovascular diseases: a meta-analysis of randomized controlled trials. JAMA. 2006 Dec 13;296(22):2720-6. doi: 10.1001/jama.296.22.2720. PMID 17164458
- BACKGROUNDClarke R, Armitage J, Lewington S, Collins R; B-Vitamin Treatment Trialists' Collaboration. Homocysteine-lowering trials for prevention of vascular disease: protocol for a collaborative meta-analysis. Clin Chem Lab Med. 2007;45(12):1575-81. doi: 10.1515/CCLM.2007.346. PMID 18265450
- BACKGROUNDVan Guelpen B, Hultdin J, Johansson I, Hallmans G, Stenling R, Riboli E, Winkvist A, Palmqvist R. Low folate levels may protect against colorectal cancer. Gut. 2006 Oct;55(10):1461-6. doi: 10.1136/gut.2005.085480. Epub 2006 Apr 25. PMID 16638790
- BACKGROUNDHultdin J, Van Guelpen B, Bergh A, Hallmans G, Stattin P. Plasma folate, vitamin B12, and homocysteine and prostate cancer risk: a prospective study. Int J Cancer. 2005 Feb 20;113(5):819-24. doi: 10.1002/ijc.20646. PMID 15499634
- BACKGROUNDCole BF, Baron JA, Sandler RS, Haile RW, Ahnen DJ, Bresalier RS, McKeown-Eyssen G, Summers RW, Rothstein RI, Burke CA, Snover DC, Church TR, Allen JI, Robertson DJ, Beck GJ, Bond JH, Byers T, Mandel JS, Mott LA, Pearson LH, Barry EL, Rees JR, Marcon N, Saibil F, Ueland PM, Greenberg ER; Polyp Prevention Study Group. Folic acid for the prevention of colorectal adenomas: a randomized clinical trial. JAMA. 2007 Jun 6;297(21):2351-9. doi: 10.1001/jama.297.21.2351. PMID 17551129