Cold things allergy. Systems strong?

Hi, I and my wife, we both have allergy from cold things like cold air, eating & drinking cold things and of course from dust. When we wake up from our bed and trying to get some fresh air we start sneezing and end up with cold (running nose). We sneeze continuously which is a big deal. We are able to eat green vegetables but we are not consuming fruits as we need to on daily basis or even weekly basis. Can you please advise if we will start taking some multivitamins that will be great to recover our life from cold things allergy and will make our immune systems strong? If we will then please suggest the best multivitamin supplement in the market for me and for my wife as well. Thanks for your precious time and advice :)