I thought this would be an impossible case. Sara has a health condition that requires a Vitamin B12 injection every 3 weeksa tough challenge for acne prone skin, as B12 is notorious for I thought this would be an impossible case. Sara has a health condition that requires a Vitamin B12 injection every 3 weeksa tough challenge for acne prone skin, as B12 is notorious for Replying to @Angela Vitamin B12 supplements can trigger an acne like eruption, as can vitamin B6 & biotin supplements. In contrast to acne, there are no comedones. Once the supplements are stopped, Does B12 Cause Acne? (HINT: It Depends)