What Causes Excessive Urinating After Taking Multivitamin Maxamin Forte?

Am 2o years due to my small size i decided to take multivitamin maxamin forte but since then have been over urinating which made me worry till went for medical check up like ultra sound,UTI but doc said am fine now 4years am still having same problem which has even worsen my weight to 36,help me am really worried and uncomfortable especially excessive urinating.