The deterioration of bones and muscles is not a question of nutrition, it's owed to the absence of Mother Earth's gravity.
It is very much a question of a working digestion system: the bone and muscle mass wouldn't go anywhere unless normal circulation were carrying it away.
And the cryosleep process must slow down all aspects of "life", or else the victims would die of aspects-left-unfozen (such as thermodynamically driven diffusion being out of synch with muscle-driven circulation). Basically, that means slowing down of many types of ailment as well. Radiation damage wouldn't be stopped as such, but certain other external attacks would, as long as their propagation through the body depended on a working circulation. Calcium loss is one of those.
OTOH, let's remember that artificial gravity staying on for centuries or millennia isn't particularly rare. In "Beyond the Farthest Star", AG had been running for three hundred million years, on a ship deemed simply "dead" by Spock. Apparently, the power consumption of the technology is either extremely low, or then does not apply - once you turn it on, it will provide free gravity until you again briefly apply power to turn it off.