Hi, welcome to the forum, your history is suggestive of that you may be having drug allergy to vitamin formulation. You may be hypersensitive to any component of the formulation. From your history it is suggests that you are intolerant to formulations of vitamin esp. if lactose or lactose like base is used.
Abdominal bloating can also be seen due to hyperacidity, air swallowing or intolerance to other foods like gluten, certain wheat etc.
You need to practice correct technique of breathing to avoid air swallowing. You also need to avoid spicy food, caffeine, vinegar, alcohol etc. Semithicone, against prescription, will help.
You need to discontinue the vitamins and go for other brands having different components. See whether you are comfortable with the new drug. I suggest you to consult physician. Take care and regards.
u can be allergic 2 the vitamins check with ur medical doctor he may order a blood test