Hair

Does a vitamin deficiency cause hair loss? Here is the evidence map for iron, biotin, zinc, B12, and protein, and when testing makes sense.

What does your hair say about your health? A complete guide to shedding, thinning, patches, graying, and dandruff, and when to see a doctor.

Hair grows about half an inch a month, so “slow growth” is often breakage or shedding. Learn the causes and what actually helps.

Dandruff is a yeast-and-oil scalp condition, not a hygiene or vitamin problem. Learn what causes flakes and how medicated shampoos work.

Hair thinning is usually gradual pattern loss, not a vitamin emergency. Learn what causes it in men and women, and what treatments can help.

Dry, brittle hair is usually damage from heat, chemicals, or overwashing, not a vitamin problem. Learn the causes, what helps, and when to see a doctor.

A smooth round bald spot is usually alopecia areata, an autoimmune condition, not a vitamin problem. Learn the causes, outlook, and when to see a doctor.

Gray hair is mostly genetics and age, not a vitamin deficiency. Learn what causes graying, the popular myths, and when a doctor visit makes sense.

Hair falling out in clumps is alarming but usually temporary shedding from a known trigger. Learn the causes, the red flags, and when to see a doctor.

Hair loss has many causes, from normal shedding to stress, iron, and hormones. Learn what your shedding means and when to see a doctor.