I am on the same thing and my doctor said it is normal!!!! no worries
Is this a weight loss question?
Would the pills happen to be yellow? If so, it would be the dye in them that's causing your urine to be yellow. If the pills aren't yellow, you might want to look at other supplements you might be taking. Another thing is if you don't go to the bathroom often and drink plenty of water, your urine becomes more concentrated and can turn a darker color, plus have more of an odor.
B vitamins are water soluble, so if you don't really need them, they will leave the body via the urine. That doesn't mean you aren't absorbing them; it means you have enough.