Are you asking if tortoises can eat sprouts? Bean/alfalfa type sprouts would be ok to feed in moderation as part of a nice, varied diet.
A tortoise's shell becomes soft because the tortoise isn't getting the calcium/vitamin d3 it needs to maintain hard shells. So the body starts to take the calcium from the shell and bones to survive.
Calcium won't work on its own. The calcium joins with the vitamin d3 from the sun to strengthen the bones and shell. That's why I always say a tortoise's number 1 home should be outside. His secondary home can be indoors during cooler weather, but without the sun, you're going to start to see problems.