Vitamin B supplements have been shown in recent research to possibly reduce the risk of certain cancers. The evidence is nuanced and varies depending on the type of cancer, the specific vitamin B required, and individual factors such as genetics and overall health. We're taking this opportunity to review the available research on how the B vitamins do (and don't) seem to impact various cancers.
Some forms of vitamin B play critical roles in DNA repair, gene regulation, and immune function—all factors that impact cancer development. For example, vitamin B6 has been consistently linked to a 30–50% reduction in colorectal cancer risk, likely due to its involvement in one-carbon metabolism, which is essential for DNA synthesis and methylation, and its anti-inflammatory and antioxidant properties. High preoperative vitamin B6 levels are also associated with increased survival in colorectal cancer patients.
Vitamin B3 (nicotinamide) has garnered attention for its potential to reduce the risk of skin cancer recurrence. In a major 2025 study among 33,000 veterans, those taking B3 supplements experienced a 53% reduction in new skin cancers, with participants consuming 500 milligrams twice daily for at least 30 days.
Findings for Various B Vitamins
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B6: Most consistently associated with reduced risk of colorectal, breast, nasopharyngeal, and pancreatic cancers. Also offers benefits for alleviating chemotherapy-related side effects.
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B3: Shown to significantly lower the recurrence of skin cancer.
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B9 (Folate): Associated with decreased risk of some breast cancers, especially in women with BRCA1 mutations. However, excessive intake may be linked to increased risk in other cancers or stages.
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B12: Evidence is mixed, with some studies observing no risk reduction and, in rare cases, potential increases in risk with high-dose supplementation.
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B complex: May boost your mood and reduce symptoms of depression and anxiety, even in people without B vitamin deficiencies.
Vitamin B supplements, particularly B6 and B12, have shown protective effects against certain types of cancer in recent research. While there is promising evidence, the use of B supplements is not universally recommended for cancer prevention because:
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Effects depend on the type of vitamin B, dosage, individual genetics, and the specific cancer.
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Excessive supplementation, especially at very high doses, has in some cases been linked to adverse outcomes or increased cancer risk.
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Most professional guidelines still stress the importance of obtaining B vitamins from a balanced diet rather than from high-dose supplements, except when medically necessary.
So in the end, is supplementing with vitamin B going to radically reduce your risk of cancer? Probably not. But that's never been the reason to supplement with B's.
The best reason to take B vitamins (like our CoEnzyme-B Complete) is because they're critical for converting food into the actual energy your body uses on a cellular level. The modern American diet doesn't include nearly enough of the whole, live foods necessary. What's worse, the nutrient density of the foods we are eating has been decreasing over time.
Beating cancer isn't a great reason to take B's, but having enough energy to keep up with daily routines certainly is.
Sources:
https://pmc.ncbi.nlm.nih.gov/articles/PMC11900642
https://www.sciencedirect.com/science/article/pii/B9780323902564000011
https://askjoedimatteo.com/products/niacinamide?_pos=1&_sid=f31a7268d&_ss=r
https://askjoedimatteo.com/products/methylation-essentials?_pos=1&_sid=f99b38a9a&_ss=r
https://www.healthline.com/health/nutrition/folate
https://www.mayoclinic.org/drugs-supplements-vitamin-b12/art-20363663
https://askjoedimatteo.com/products/coenzyme-b-complete?_pos=1&_sid=a37e7de79&_ss=r
