Blood cells, either in circulation or within the bone marrow, account for nearly 93% of all cells within the human body. The marrow produces approximately six billion cells per kilogram of body weight per day.
Although blood cells are the most numerous cells in numbers, by weight they are far exceeded by fat cells and muscle cells. The total mass of blood cells in a 70-kg adult male is estimated at 3kg. Interestingly, there are more bacteria on the human body compared to any human cells.
Red cells are the most actively dividing cell in the body. Within a second, 200 million red cells are produced. The marrow is further able to increase its output by six times in anaemic states.
Also, to note is that 4,000 gallons (15.000 L) of fake blood was used over the 8 seasons of Game of Thrones.
Blood & Water 