Plus, the study relies on people's recall over 10 years to remember their supplement consumption, which may not be accurate, they say.
For the VITAL cohort, researchers assessed the responses of 77,118 participants who reported their intake of multivitamins, individual vitamin supplements, and any vitamin mixtures, and calculated the prior-to-study 10-year average daily doses for vitamin B6, B9, and B12. It's meant to evaluate vitamin and other mineral supplements in relation to cancer risk.
Brasky said people can easily get enough vitamin B from eating meat, chickpeas and cereal fortified with the vitamin.
A study found men who take high doses of vitamins B6 or B12 over a long period were much more likely to develop the disease. These levels were more than 11 times the recommended daily amount of B6 and 23 times that of B12. For smokers takin B12, the risk was almost fourfold higher. Those who smoke and take high-dose B vitamins should consider cutting back to doses closer to the US RDA (i.e., from a multivitamin) or getting their nutrients from diet. We found that men who took high doses of vitamin B6 and B12 from individual supplements over a long period of time (meaning, doses much higher than the US RDA and much greater than what one would receive from taking a multivitamin over the long term) were at almost 2-fold increased risk of lung cancer compared to men who did not have B6 or B12 intake from any supplemental source.
US Warns Citizens About Traveling to Cancun
Additionally, there is no evidence that criminal organizations have targeted US citizens based on their nationality. The expanded travel advisory hits at the heart of a tourism industry that brings in $20 billion a year for Mexico .
Researchers analyzed data from 77,118 participants in the Vitamins and Lifestyle (VITAL) cohort, a long-term prospective observational study created to evaluate the potential associations between cancer risk and use of vitamin or other mineral supplements. But high-dose supplements nowadays claim to boost energy, among other unproven benefits.
All participants enrolled in the state of Washington between 2000 and 2002, when they were aged 50 to 76. This is the first study to prospectively examine the effects of extended, high-dose B6/B12 supplement use and lung cancer risk.
The alarming findings of the new study appeared in the most recent edition of the Journal of Clinical Oncology. He pointed out, "When we're talking about what to be concerned about most: If you're a male smoker and you want to take B vitamins, you can stop smoking. This is certainly a concern worthy of further evaluation".
Why B vitamins influence cancer risk is not known for sure, but some believe that it is related to how B vitamins interact with the so-called one-carbon-metabolism pathway.