Vitamin B5 — pantothenic acid, from the Greek pantothen, everywhere — is a water-soluble B vitamin found in virtually all plant and animal tissues, with rich sources including chicken, offal, fish, eggs, potatoes, and wholemeal cereals. It is the core of coenzyme A, the molecule that carries acyl groups in the metabolism of fats, carbohydrates, and proteins — central to releasing energy from food and to synthesising fats and steroid hormones. True deficiency is rare precisely because the vitamin is so widespread, but experimental deprivation causes fatigue, nausea, and neurological symptoms. It is damaged by prolonged boiling and by alkaline conditions, so gentle cooking and varied eating protect intake.