Number of vitamins required in citric acid cycle is:
Four of the B vitamins are essential in the citric acid cycle and hence energy-yielding metabolism: (1) riboflavin, in the form of flavin adenine dinucleotide (FAD), a cofactor for succinate dehydrogenase; (2) niacin, in the form of nicotinamide adenine dinucleotide (NAD), the electron acceptor for isocitrate dehydrogenase, a-ketoglutarate dehydrogenase, and malate dehydrogenase; (3) thiamin (vitamin B1), as thiamin diphosphate, the coenzyme for decarboxylation in the a-ketoglutarate dehydrogenase reaction; and (4) pantothenic acid, as pa of coenzyme A, the cofactor attached to "active" carboxylic acid residues such as acetyl-CoA and succinyl-CoA Ref: Harper 28th edition, chapter 17.
2
3
4
5