Question

Functionally active form of vitamin D is:
A.Cholecalciferol
B.Ergocalciferol
C.Dehydrocholesterol
D.calcitriol

Answer 1

When the human body comes in contact with sunlight skin tends to synthesize Vitamin D in the epidermal layer of the skin. Vitamin D is needed by the human body for the absorption of calcium and phosphorus which are essential for healthy bones.

Complete answer:
When the human body comes in contact with sunlight skin tends to synthesize Vitamin D in the epidermal layer of the skin. Vitamin D is needed by the human body for the absorption of calcium and phosphorus which are essential for the healthy bones. Calcitriol is the functionally active form of vitamin D. It circulates as a hormone in the blood which plays a major role in regulating the concentration of calcium and phosphate, and promoting healthy growth. Vitamin D is also known as sunshine hormone due to its ability to be produced by the human body on exposure to sunlight.
Cholecalciferol is a type of vitamin D that is produced by the skin when it is exposed to sunlight. It is also seen in some foods and can be taken as a dietary supplement. Ergocalciferol is a type of vitamin D that is found in food and used as a dietary supplement. It is used to prevent and also to treat vitamin D deficiency. Dehydrocholesterol is a zoosterol that functions similar to a cholesterol precursor and it is photochemically converted to cholecalciferol which is a type of vitamin D, in the skin.
Therefore, the correct answer is option D i.e. functionally active form of vitamin D is calcitriol.

Additional Information: Epidermal layer is the outermost layer of the skin which protects the body from the outer environment conditions and unwanted pathogens. It consists of melanocytes which are responsible for the production of “Melanin”. The skin colour is determined by the $({{C}_{2}}7{{H}_{4}}4{{O}_{2}})$ and $({{C}_{2}}7{{H}_{4}}4{{O}_{3}})$ are responsible for the production of Melanin. The skin colour is determined by the presence of melanin pigment. More melanin darker the skin colour, lesser the melanin lighter the skin colour.

Note:
Remember that the vitamin D deficiency can cause rickets, which is a bone disorder that can severely compromise the structural integrity of the bone, leading to fractures. Vitamin D deficiency leads to other diseases and disorders also such as asthma and other lung diseases and cardiovascular diseases. Few symptoms of vitamin D deficiency are fatigue, hair loss, back pain, bone pain and so on.