no i do not think this would help. in 24 hours your blood level would return to normal. it would be like if your boat was full of water and it were raining, and you take a bucket of water out of it to stop it from sinking, the rain would just fill it back up. that's my take on it anyway. if anything, constant blood donation would leave you weak and without nutrients and iron (both of which are needed for healthy hair growth).