Given below are two statements, one to labelled as Assertion (A) and other as Reason (R) : Assertion (A|: Human body synthesises all the vitamins required by it. Reason (R) : Vitamins are essential for proper growth of the body. Select the correct answer using the codes given below. Codes:

The assertion is false. The human body cannot make all the vitamins it needs. It synthesises only a few: vitamin D in the skin under UV exposure, vitamin K partly through gut bacteria, niacin from tryptophan, and some B vitamins through intestinal flora. Vitamin C cannot be made by humans at all because we lack the enzyme L-gulonolactone oxidase, so it must come from diet. Vitamin B12 must also come from animal-source foods or fortified food.

The reason is true. Vitamins are micronutrients needed in small amounts as enzyme cofactors and for metabolic processes, and their deficiency stunts growth and causes disorders such as rickets (vitamin D) and scurvy (vitamin C).

Because (A) is false and (R) is true, option D is correct. The topic sits in the Biology and Nutrition segment of General Science, and in Mains it connects to public health programmes such as food fortification and nutrition security.

Trap: Aspirants see that vitamin D is made in the skin and wrongly generalise it to all vitamins, or they mark the reason as false because it sounds obvious. Check each statement separately.