Another B vitamin linked to worse outcomes for cancer

Key Points:

• Both low and excessively high vitamin B12 levels have been linked to increased cancer risk, highlighting the importance of maintaining a balanced intake.
• Some studies suggest that B-vitamin supplements may reduce certain cancer risks, such as skin melanomas, while others indicate that high doses of B6 and B12 supplements may increase lung cancer risk, especially in men and smokers.
• Vitamin B12 is essential for nerve cell development, red blood cell formation, and DNA synthesis, but excess B12 might support the growth of precancerous or cancerous cells, though this is not conclusively proven in humans.
• Elevated blood B12 levels are often observed in cancer patients, but it remains unclear whether high B12 causes cancer, aids its growth, or is a result of cancer; nonetheless, high B12 levels can prompt cancer screening.
• Recent research found that colon cancer patients with very high B12 levels have shorter survival times, and a study identified that vitamin B7 (biotin) may help tumors generate energy for growth.