How like lightning can a fit human body typically replace blood loss?

And what are the factors that affect the rate? If you maintain your body hydrated with sea and/or fruit juices, and devour regularly your body will will place it as fast as it can, typical within a day for a pint of blood given to a blood mound.
Typically 72 hours and you will have completely regenerate lost blood upto 2 pints. Eating simple carbohydrates will increase this production, but not decrease the time. As the blood constantly have dying cells that want to be replaced.
factors that can affect the rate? Having a spleen.