Talk to Dermatologist on Hairloss

I want to ask if someone can recommend me a good dermatologist for hairloss who doesnt prescribe tonnes of products to apply on hair and scalp cause i used to have thick hair but due to poor diet my haioss started in last 2 yrs . I got my vit D and ferritine level test done and they were below normal ( very low) so could plz anyone suggest me a good doctor