Why does vitamin B12 supplementation trigger acne breakouts in some individuals?Updated 11 hours ago
While vitamin B12 is essential for energy, nerve health, and even skin support, a small subset of individuals—especially those already prone to inflammatory acne—may experience breakouts after supplementation. This reaction is not common.
In fact, clinical observations and available research suggest it's relatively rare. One study estimates that fewer than 1 in 1,000 individuals experience B12-induced acne flares, typically in those with a pre-existing tendency toward inflammatory acne (Kang et al., 2015). In clinical practice, it’s often reported as an occasional finding—seen once or twice a year in high-volume dermatology or nutrition settings.
Why does this happen in some people?
1. Bacterial metabolism changes:
Supplemental B12 alters the behavior of Cutibacterium acnes (formerly Propionibacterium acnes), a dominant skin bacterium. When external B12 is introduced, it suppresses the bacteria’s own B12 production, causing a shift that leads to increased porphyrin production—compounds that can trigger inflammation (Kang et al., 2015).
2. Immune activation:
These porphyrins stimulate the immune system in the skin’s oil glands (pilosebaceous units), contributing to the formation of acne lesions (Colmone, 2015).
3. Potential upregulation of inflammatory pathways:
Vitamin B12 may also activate Toll-like receptor 2 (TLR2), part of the body’s innate immune response, which is linked to inflammatory acne development. This contrasts with acne treatments like isotretinoin, which reduce TLR2 activity (Cheng & Oliver, 2016).
Why doesn’t it happen to everyone?
This response depends on genetics, microbiome composition, and immune sensitivity. Many people benefit from B12 with no skin issues, especially when correcting a deficiency.
What can you do if you're concerned?
If you have a history of inflammatory acne:
Start with low doses of B12 and increase gradually
Choose food-based sources when possible
Work with a healthcare professional to monitor skin responses
References:
Kang D, et al. Sci Transl Med. 2015;7(293):293ra103.
Colmone A. Science. 2015;348(6239):1031.
Cheng JB, Oliver BG. J Invest Dermatol. 2016;136(3):618–621.