Association of Supplemental Vitamin B Use and Lung Cancer in VITAL Cohort


Key Points

  • Use of vitamin B6 and B12 as individual supplement sources, but not in multivitamins, was associated with an increased risk in men.
  • An increased risk was present for all histologic subtypes except adenocarcinoma.

In a study reported in the Journal of Clinical Oncology, Brasky et al found that the use of individual source supplemental vitamins B6 and B12 was associated with an increased risk of lung cancer among men in the Vitamins and Lifestyle (VITAL) cohort. Several B vitamins, including B6, B9 (folate), and B12, interact with homocysteine and methionine in the one-carbon metabolism pathway, which plays a role in DNA integrity maintenance and regulation of gene expression; this interaction may cause disruption of pathway processes and promote carcinogenesis.

Study Details

The study involved 77,118 participants in the VITAL cohort aged 50 to 76 years of age who were recruited between October 2000 and December 2002; the cohort was designed specifically to examine potential associations between supplement use and cancer risk. A total of 808 incident primary invasive lung cancers were identified. The exposure of primary interest was 10-year average daily dose from individual and multivitamin supplements.

Associations With Lung Cancer

Use of supplemental vitamins B6, folate, and B12 was not associated with an increased lung cancer risk among women. On multivariate analysis, use of vitamin B6 (hazard ratio [HR] = 1.84, 95% confidence interval [CI] = 1.01–3.36) and B12 (HR = 2.42, 95% CI = 1.49–3.95) from individual supplement sources but not from multivitamins was associated with an increased risk of disease in men. Based on 10-year average daily dose, an increased risk was restricted to men in the highest categories of supplemental intake of vitamin B6 (> 20 mg/d; HR = 1.82, 95% CI = 1.25–2.65) and B12 (> 55 µg/d; HR = 1.98, 95% CI = 1.32–2.97) vs nonusers. The risk was higher among men who were cigarette smokers at baseline. The association of supplemental B6 and B12 intake and risk was present for all histologic subtypes except adenocarcinoma, the subtype with the least-strong association with smoking.

The investigators concluded: “This sex- and source-specific association provides further evidence that vitamin B supplements are not chemopreventive for lung cancer and may be harmful.”

The study was supported by National Institutes of Health grants.

Chi-Ling Chen, PhD, of the College of Medicine, National Taiwan University, is the corresponding author of the Journal of Clinical Oncology article.

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.