Hair loss can be a number of factors and the first one to consider is your diet. Have you been for blood tests and how is your thyroid and your iron levels? If it is established that these are normal, then one would look at your stress levels and see if they are more than normal. Once all this has been taken into consideration, then we would need to look at family history. Usually if it is a family history then there is not much you can do about it.
I would start by making sure that you are eating healthy – start your day with protein and use good products to keep your scalp clean. I would only use a multivitamin prescribed by a doctor or a trichologist. Also, remember that it takes three to four months before you will see any growth.