Vitamin D is obtained from which sources and what roles does it play in the body?

• A. Vitamin D is obtained exclusively from dairy products and has no role in bone health.
• B. Vitamin D is obtained from sun exposure, fortified foods, and supplements; roles include calcium and phosphorus homeostasis and bone health; deficiency leads to rickets/osteomalacia.
• C. Vitamin D is only produced in response to cold weather and has no effect on calcium.
• D. Vitamin D is produced in the brain and is not related to bones.

Answer: (B)