The nurse is teaching a client with early osteoporosis the importance of including vitamin D with calcium supplements. Which information is most important for the nurse to provide to encourage the client's compliance in the management of progressing osteoporosis?

Choice A reason: Avoiding sunscreen is not recommended as it increases the risk of skin cancer; vitamin D can be obtained safely through diet and supplements. Choice B reason: While it is true that vitamin D and calcium are balanced with phosphorus, this statement does not directly encourage compliance with supplementation. Choice C reason: Although calcium uses vitamin D produced by sunlight exposure, relying solely on sunshine is not sufficient, especially for individuals at risk of osteoporosis. Choice D reason: Emphasizing that vitamin D enhances calcium absorption into the bone provides a clear rationale for the client to comply with the supplementation regimen.