vitamin B7 vitamins B7 vitamin B7 vitamin B-7 vitamin B7 vitamer Any member of a group of vitamers that belong to the chemical structural class called biotins that exhibit biological activity against vitamin B<small>₇</small> deficiency. Vitamin B<small>₇</small> deficiency is very rare in individuals who take a normal balanced diet. Foods rich in biotin are egg yolk, liver, cereals, vegetables (spinach, mushrooms) and rice. Symptoms associated with vitamin B<small>₇</small> deficiency include thinning hair, scaly skin rashes around eyes, nose and mouth, and brittle nails. The vitamers include biotin and its ionized and salt forms. vitamin B7 vitamers B vitamin