Could the vitamine b12 deficiency cause sleep apnea?

No: B12 deficiency can cause megaloblastic anemia, sensory ataxia, sub-cortical dementia and neuropathy, but not cause obstructive, central or mixed sleep apnea. (at least not directly) Pulmonary hypertension can be exacerbated by severe anemia, but generally speaking B12 deficincy does not go undiagnosed long enough to produce significant anemia to contribute to this uncommon cause of OSA