Yeah the first moult is known as a ' soft ' moult but the ' hard ' moult is far more taxing on the bird. You can get a great product called ' Calcivet ' from your feed store. Just add to the birds water , it's the easiest way to administer extra calcium.
I use avi-calcium soluble calcium, have used calivet in the past though. Whatever's in stock on planetpoultry.com really. Both are good.
Yeh it was my araucana Mabel's first major mature moult this year, and Beatrice my belgian as well. Both were a little out of sorts, poor Mabel was just covered in spikey pins poor girl. She looks amazing now, and so soft. Perfect winter cuddlin' chicken.