Vitamin B5 (Pantothenic Acid), another of the B complex vitamins, is a yellow viscous oil found usually as the calcium or sodium salt—that is, calcium pantothenate. It is present in all living cells and is very important to metabolism where it functions as part of the molecule called coenzyme A or CoA. Pantothenic acid is found in yeasts, molds, bacteria, and plant and animal cells, as well as in human blood plasma and lymph fluid.

B5 is stable to moist heat and oxidation or reduction (adding or subtracting an electron), though it is easily destroyed by acids (such as vinegar) or alkalis (such as baking soda) and by dry heat. Over half of the pantothenic acid in wheat is lost during milling, and about one-third is degraded in meat during cooking. In many whole foods, vitamin B5 is readily available.

Pantothenic acid is synthesized by bacterial flora in the intestines. Pantothenic acid, as a constituent of coenzyme A, plays a key role in the metabolism of carbohydrates, proteins and fats, and is therefore important for the maintenance and repair of all cells and tissue. It is involved in reactions that supply energy, in the synthesis of such vital compounds as sterols (cholesterol), hormones (growth, stress and sex hormones), neurotransmitters acetylcholine), phospholipids (components of cell membranes), porphyrin (component of hemoglobin, the oxygen-carrying red blood cell pigment) and antibodies, and in the metabolism of drugs (sulfonamides). It is released from coenzyme A in food by a series of enzyme reactions and then absorbed into the portal circulation and transported to the tissues, where resynthesis of the coenzyme occurs. It stimulates the adrenal glands and increases the production of cortisone for healthy nerves and skin. Another essential role of pantothenic acid is its participation in acyl carrier protein, an enzyme involved in the synthesis of fatty acids.

Vitamin B5 plays an important role in the secretion of hormones, such as cortisone because of the role it plays in supporting the adrenal gland. These hormones assist the metabolism, help to fight allergies and are beneficial in the maintenance of healthy skin, muscles and nerves. Pantothenic acid is also used in the release of energy as well as the metabolism of fat, protein and carbohydrates. It is used in the creation of lipids, neurotransmitters, steroid hormones and hemoglobin. Some are of the opinion that pantothenic acid is also helpful to fight wrinkles as well as graying of the hair.

With Vitamin B5 in short supply symptoms like fatigue, headaches, nausea, tingling in the hands, depression, personality changes and cardiac instability have been reported. Frequent infection, fatigue, abdominal pains, sleep disturbances and neurological disorders, including numbness, paresthesia (abnormal sensation such as "burning feet" syndrome), muscle weakness and cramps are also possible indications that this nutrient is in short supply. Biochemical changes include increased insulin sensitivity, lowered blood cholesterol, decreased serum potassium, and failure of adrenocorticotropin to induce eosinopenia.

It does not appear to be toxic in high dosage, although diarrhea, digestive disturbances and water retention have been reported on dosage exceeding 10 g a day. Taking 1,500 mg a day over an extended period may cause sensitivity to the teeth.

Pantothenic acid can be lost in cooking - particularly with roasting or milling, as well as when exposed to acids like vinegar, or alkali such as baking soda. It is also destroyed to a large degree in canning.

Beef, brewer’s yeast, eggs, fresh vegetables, kidneys, legumes, liver, mushrooms, nuts, pork, royal jelly, saltwater fish, torula yeast, whole rye flour, and whole wheat.