just out of interest, I used to have terrible cracked heels. So bad it was embarrasing to be seen without shoes on and they would bleed from the deep cracks.
I was put on Thyroxine about 3 months ago for a low thyroid and the cracked heels have completely repaired themselves.
Turns out that cracked heels are a symptom of Low thyroid and I had battled with the heels ( and low thyroid) for years and years, not knowing that was the problem!
Not saying that everyone with cracked heels has a Thyroid issue.... but hey! you never know