Which of the following vitamins is considered to be a hormone?

Explanation

Prohormone: Vitamin D is considered a prohormone because the body can synthesize it in the skin when exposed to sunlight.

Activation: The body then converts this inactive form of vitamin D into the active hormone, called calcitriol, primarily in the kidneys.

Function: This hormone's main function is to regulate calcium and phosphorus levels in the blood, which is vital for bone health.