Hair Fall and weakening. Similar stuff?

Hi doctor, I know this is a very common question and there are no specific answers for this but since I'm suffering much, hence, the question, again. I'm suffering fro too much hair fall and I really do not want to visit a doctor for this issue since, I have visited more than 4 and there is no improvement in this case. Also, I have done all the tests as prescribed the doctors and all the reports are fine, except for Vit D, which is pretty low. I am taking Uprise d for that, weekly once. I wanted to know some of the general do's and don'ts which will help me to cope with my problem. Also, this issue started since I shifted to Bangalore, 2 years back. Here, people have hair and skin problems because of the water and pollution. Is there something that you would recommend- like any particular shampoo or oil or similar stuff? Would be great. Thanks, doctor.