Yes, these ones are totally okay. I recommend everyone has them in their chicken first aid kit; they’ve saved my egg bound hen for sure. I’ve recently read when they’ve come in handy for vent prolapses, too.
I personally do only supplement (the vitamin) if there is an instance of egg binding or...
Just because I have the picture on hand, here is what I use - they’re available at most drug or grocery stores. These exact ones are petites so I have to give 1 and 1/2 to get to 600mg.
What works for us, especially when we start getting soft eggs or egg bound hens, which is pretty consistent in 1 hen in our flock, is restricting all treats and limiting feed to layer pellets. Ensuring oyster shell is available on the side and in the event of soft eggs being laid or egg binding...