Hairloss is a symptom of both PCOS and hypothyroid. (Lucky me

)
But, if your calories and weightloss go too low too fast that can also be an issue. So, hairloss sometimes happens with anorexics, bulimics and extreme dieters.
It can also be from malnutrition. B and C vitamins in high doses will help some. Brewers yeast is another natural supplement you can try. Biotin is one of the specific B vitamins that helps with hair and nails. I take Super B Complex and Biotin.
I have lots of new growth. It doesn't always "stick." I do get a sort of fuzzy look from the tiny new hairs...but truth is it does make my hair seem fuller.