Which of the following is a metabolic function of the skin?

• A. Regulation of body temperature
• B. Detection of touch stimuli
• C. Synthesis of vitamin D
• D. Production of melanin

Answer: (C)

Verified step by step guidance

1. Understand the term 'metabolic function'—it refers to chemical processes that occur within the body to maintain life, such as synthesis, breakdown, or transformation of substances.
2. Review the functions of the skin. The skin has various roles, including protection, sensory reception, thermoregulation, and metabolic functions.
3. Focus on the metabolic function of the skin. The synthesis of vitamin D is a key metabolic process that occurs in the skin when exposed to ultraviolet (UV) light from the sun.
4. Explain the process of vitamin D synthesis: UV light converts 7-dehydrocholesterol in the skin into cholecalciferol (vitamin D3), which is then transported to the liver and kidneys for further activation into its biologically active form, calcitriol.
5. Clarify why the other options are not metabolic functions: Regulation of body temperature is a thermoregulatory function, detection of touch stimuli is a sensory function, and production of melanin is a protective function against UV radiation, not a metabolic process.