Lack of enzymes/LOW stomach acid are the main reasons for acid reflux and can also cause gastritis (inflammation of the stomach). When you don't have enough stomach acid, you cannot absorb vitamin B12 and other essential vitamins. This will cause fatigue and other health problems. You may have the H Pylori bacteria, which causes low stomach acid also, but if this is ruled out, i highly recommend trying digestive enzyme supplements with each meal. Some digestive enzymes contain betaine hydrochloride to improve stomach acid.