<prompt> Which of the following vitamin is synthesised in the body?Nicotinic acidAscorbic acidVitamin-DVitamin-B  <response>: Vitamin D is synthesized in the skin. 7-Dehydrocholesterol an intermediate in the synthesis of cholesterol that accumulates in the skin undergoes a nonenzymatic reaction on exposure to ultraviolet light, yielding previtamin D. This undergoes a fuher reaction over a period of hours to form cholecalciferol, which is absorbed into the bloodstream. Ref: Bender D.A. 2011. Chapter 44. Micronutrients: Vitamins Minerals. In D.A. Bender, K.M. Botham, P.A. Weil, P.J. Kennelly, R.K. Murray, V.W. Rodwell Eds, Harpers Illustrated Biochemistry, 29e. 