Overdose?

I am buying a foal and want to get him started on your red cal as soon as possible.  He and his dam presently have not had access to ANY salt or minerals for the last 2 months.  Is it possible to overdose on the red cal in their depleted state.  Should I start slow with small amounts and build up to to free choice?

As long as they have plenty of water they can’t get too much. Thanks for asking!

TheNaturalVet