Everybody sheds hair, whether you suffer from MPB or not. The range is ~ 50-200 hairs a day, depending on your circumstances. Also, sheds can happen at different times of year and for different reasons. Weather, seasons, stress, diet, medication, etc. can all contribute to the speeding up or slowing down of the hair cycle. If there is no reason for your hair to be falling out (other than normal hair growth cycles), it will grow back when the time comes.
You should read up on anagen, catagen, and telogen hair phases.
Nizoral will help slow down shedding (for most people) if you are shedding at an increased rate because of scalp inflammation or an overgrowth of scalp fungus, which usually causes dandruff. It does a pretty good job of calming the scalp (for most people).
I have been using Nizoral for years and I believe it has slowed down the rate at which I am balding (from dandruff and scalp DHT levels).