Can B12 Cause Flushing?

Can B12 Cause Flushing? Can b12 cause flushing? Very high doses of vitamin B12 may sometimes cause acne. Other uncommon side effects include skin rash, hot flushes, nausea, dizziness and cardiac arrhythmias. Can Vitamin B12 make your face red? However, supplementing with excessively high levels of B12 has been linked to some negative side effects.