Yes, but drinking blood won't recycle blood to near-equal amounts.
That's true, it only provides the nutrients.
In our recycling, we have to add energy. The Ecosphere Two project ran into a problem of carbon dioxide outgassing from the soil. That hasn't been a problem for us because we just separate it and compress it for rocket fuel.
One thing we learned from them was how to use daily expansion of the atmosphere to help move it around. Our enclosed space is larger too.