Health In Focus
  • Vitamin supplements are used to increase energy and improve metabolism. However, high doses of supplements can cause side effects
  • Men who took high doses of vitamin B6 and B12 for ten years were at a higher risk of cancer
  • Lung cancer risk was three times higher among male smokers who also took vitamin B supplement.

Long-term supplementation of high doses vitamin B6 and B12 can increase the risk of lung cancer in men, finds a new research. The risk of lung cancer was even higher among smokers.

Link Between Vitamin B and Lung Cancer

The study was conducted by epidemiologists from The Ohio State University Comprehensive Cancer Center - Arthur G. James Cancer Hospital and Richard J. Solove Research Institute (OSUCCC - James), Fred Hutchinson Cancer Research Center and National Taiwan University.
High Dose Vitamin B Supplements can Increase Risk of Lung Cancer

Vitamin supplements have been thought to reduce cancer risk. The current study was the first to look at the long-term consumption of high dose vitamin B6, B12 and lung cancer.

The research team led by Theodore Brasky, Ph.D., of the OSUCCC - James, analyzed data from more than 77,000 patients participants in the VITamins And Lifestyle (VITAL) cohort study. VITAL, is a long-term prospective observational study designed to evaluate vitamin and other supplements associated with cancer risk.

The study participants aged between 50 and 76 years were recruited in the state of Washington between the years 2000 and 2002. The participants history forB-vitamin usage over the past ten years was recorded at the beginning of the study, Information of the dosage of the vitamin supplements was also obtained.

To analyze the link between B vitamins and lung cancer risk the research team used statistical techniques to adjust for factors including personal smoking history, age, race, education, body size, alcohol consumption, history of cancer, chronic lung disease family history of lung cancer and use of anti-inflammatory drugs.

The study found that the lung cancer risk was higher among male smokers who took more than 20mg of vitamin B6 and 55mg of vitamin B12 a day for ten years.

Male smokers who took higher doses of vitamin B6 were three times more likely to develop lung cancer.

Male smokers who took higher doses of vitamin B12 were four times more likely to develop lung cancer compared to the non-users.

"This sets all of these other influencing factors as equal, so we are left with a less confounding effect of long-term B6 and B12 super-supplementation. Our data shows that taking high doses of B6 and B12 over a very long period of time could contribute to lung cancer incidence rates in male smokers. This is certainly a concern worthy of further evaluation," said Brasky.

The findings of the study relate to doses among those taking multivitamins every day for ten years.

"These are doses that can only be obtained from taking high-dose B vitamin supplements, and these supplements are many times the U.S. Recommended Dietary Allowance," added Brasky.

The findings of the study are published in the Journal of Clinical Oncology.

Two more additional studies will be conducted to further evaluate the high dose of long-term vitamin B6 and B12 supplementation and lung cancer risk. The first study will examine the associations in post-menopausal women to confirm the current finding of no elevated risk in women. The second study will examine long-term supplementation of vitamin B6 and B12 in a second large prospective study of men to determine whether the lung cancer risk in the current study can be replicated.

Vitamin B6 and B12

Vitamins B6 and B12 are vital micro nutrients that keep the red blood cells healthy and also helps to process carbohydrate, protein, and fat. B vitamins are naturally found in meat, fish, cheese, eggs, and milk. Breakfast cereals have also been fortified with vitamin B.

B vitamin supplements are prescribed to boost energy and metabolism. The recommended dose of vitamin B6 is around 1.4mg a day for men and 1.2mg a day for women, while for B12 it is 1.5mcg a day for adults.

Reference :
  1. Long-Term, Supplemental, One-Carbon Metabolism-Related Vitamin B Use in Relation to Lung Cancer Risk in the Vitamins and Lifestyle (VITAL) Cohort - (
  2. Theodore M. Brasky, Emily White, Chi-Ling Chen. Long-Term, Supplemental, One-Carbon Metabolism-Related Vitamin B Use in Relation to Lung Cancer Risk in the Vitamins and Lifestyle (VITAL) Cohort. Journal of Clinical Oncology (2017). DOI: 10.1200/JCO.2017.72.7735

Source: Medindia

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