Question

Which of the following is necessary for the dermal synthesis of Vitamin D ?

• A. Gamma Rays
• B. X-Rays
• C. Infrared rays
• D. Ultraviloet rays

Answer 1

Answer:

D. Ultraviloet rays

• Vitamin D₂ (ergocalciferol) is largely human-made and added to foods
• Vitamin D₃ (cholecalciferol) is synthesized in the skin of humans from 7-dehydrocholesterol and is also consumed in the diet via the intake of animal-based foods.
• Vitamin D is a closely related compound. The synthesis of this vitamin starts when the precursor molecules are activated in the skin by the UV (ultraviolet) rays in the sunlight.
• In the kidneys and the liver, the enzymes then modify the molecule ultimately yielding calcitriol, which is the most active form of vitamin D.
• This calcitriol supplies the homeostasis of body fluids by assisting the process of absorption of calcium in the food.
• As per the synthesis sequence explained, vitamin D is deemed to be a hormone as it is yielded in the body in one location and transported by the blood, and shows effect in the other location.
• Hence, skin is deemed to be an endocrine organ.