The manufacturer and conventional medical wisdom says to take it without food or other medicines 1/2 - 1 hour before breakfast. That's when the maximum absorption will take place. Taking it when food is present in the gut can reduce absorption up to 40%. Taking it with iron, calcium, or estrogen-containing meds reduces absorption even more radically. It's safest to take these at least 4 hours apart from the Synthroid.
I don't understand why countrycarole's MD would tell her differently.