Yes. Mine are free range and eat a lot less than they did when locked up, but I believe they need it available, as well as oyster shell for layers, and even grit, unless you have a lot of fine granite lying around. Lots of folks on here will disagree with the grit, but I figure that even if they are right, it's not exactly a bank breaker, costs me about $8 for a bag that lasts me 2-3 years.
That's one of those things that is debated on here. Many people say they have been doing it for years and report no trouble with their eggs; others say it does not provide enough calcium, or could injure the bird internally with a sharp edge. I'm not taking sides on that one.