I was living in a province before but now that I moved here in the city for work, I usually having colds and coughs every time I'm exposed to low temperatures.. I find the city polluted, and the thing is I used to eat a lot of vegetables in the province but here in the city I eat seldom. I'm taking ascorbic acid once or twice a day depending on my daily activity.. would it be effective for me? or shall I take multivitamins? thank you so much