Vitamin B5 forms coenzyme A, which your body needs to turn food into energy. The standard supplemental form is calcium pantothenate because it absorbs easily.
Many people take B5 alone or inside a B complex, best with a meal. A derivative called panthenol appears in skin and hair products for topical use.
Large doses far above normal intakes sometimes cause mild diarrhea. The vitamin has no known major drug interactions and a strong safety record at typical supplement amounts.