vitamin B5 vitamin B5 vitamer vitamin B5 vitamers Any member of a group of vitamers that belong to the chemical structural class called pantothenic acids that exhibit biological activity against vitamin B<small>₅</small> deficiency. Deficiency of vitamin B<small>₅</small> is rare due to its widespread distribution in whole grain cereals, legumes and meat. Symptoms associated with vitamin B<small>₅</small> deficiency are difficult to asses since they are subtle and resemble those of other B vitamin deficiencies. The vitamers include (<i>R</i>)-pantothenic acid and its ionized and salt forms. vitamin B5 vitamin B-5 vitamins B5 B vitamin