Question

Your hair is composed of live cells that need vitamins and nutrients.

Answer 1

Not exactly. The part of your hair you see (the shaft) is dead, keratinized cells and does not take up nutrients. The living tissue is in the hair follicle (the bulb) beneath the scalp, and those cells need blood-supplied nutrients to form new hair and support growth.

Key points
- Hair shaft vs. follicle: the shaft is dead; the follicle/bulb is alive and is what needs nutrients.
- Growth cycle: hair grows in anagen (active), then catagen (transition), then telogen (rest/shedding). Nutrition matters while follicles are in anagen.
- Important nutrients: adequate protein, iron, zinc, biotin, vitamins D and B vitamins (including B12), and essential fatty acids. Deficiencies in these can cause thinning or slow growth.
- Supplements: useful if you have a proven deficiency, but not helpful if your diet is adequate. Excess of some vitamins (e.g., vitamin A) can cause hair loss.
- Topical products can protect the shaft or improve scalp health but cannot “feed” dead hair; only the follicle’s blood supply can deliver nutrients.

If you’re worried about hair loss or poor growth, a clinician can check for common causes (iron deficiency, thyroid disease, hormonal issues) and advise whether testing or supplements make sense.