The commonly cited side-effects - cardiac problems, gastrointestinal issues, irregular or absent periods - present a familiar list
Signs that you may be deficient in B12 may include (but are not limited to): weakness, tiredness, or light headedness, heart palpitations and shortness of breath, nerve problems like numbness or tingling, muscle weakness and loss of appetite/weight loss
Prospective, double-blind, randomized, placebo-controlled comparison of acetazolamide versus ibuprofen for prophylaxis against high altitude headache: the Headache Evaluation at Altitude Trial (HEAT)
15 HAD symptoms broadly include weight loss, poor appetite, slow recovery from fatigue, lethargy, irritability, lack of willpower to start new tasks, slowed mental processes, dull affect, and impaired cognitive function