Do supplements work against hair loss? Ferritin, vitamin D and zinc

Supplements are not miracles

Supplements cannot cure hereditary hair loss. No pill counteracts DHT-driven miniaturisation; that takes medical treatment such as Finasteride. Supplements primarily make a difference in one scenario: when the hair loss is caused or worsened by a genuine nutritional deficiency.

If you have no deficiency, extra vitamins rarely produce more hair, and in certain cases (for example too much selenium or vitamin A) an overdose can actually worsen the hair loss. The rule is to measure, not to guess.

Measure before you supplement

Get a blood test before you buy supplements. The most relevant markers are:

• Ferritin (iron stores): ideally above 70 ng/mL for optimal hair growth; a low level is a frequent and overlooked cause, especially in women
• Vitamin D: deficiency is widespread at northern latitudes and is linked to hair loss
• Thyroid function (TSH): the thyroid affects the whole hair cycle
• Zinc and B12 where diet gives cause for suspicion, for example on a vegetarian or vegan diet

The most important nutrients

Iron is a building block for cell division in the follicle, and vitamin D plays a role in the renewal of the hair cycle. Zinc is necessary for tissue repair, and B12 and folate support the rapidly dividing cells in the follicle.

Biotin is often mentioned in advertising, but genuine Biotin deficiency is rare, and supplements only benefit the few with a real deficiency. For most people they are a waste of money. See specific doses and evidence in the section on supplements in Slowing hair loss without surgery.

Diet rather than pills

For most people a varied diet is the best "supplement strategy". Red meat, fish, eggs, pulses and green leafy vegetables cover iron; oily fish and sunlight provide vitamin D; shellfish, meat and seeds deliver zinc. Sufficient protein is the foundation, since hair itself is keratin (protein).

Severe diets and a very one-sided diet are, by contrast, a classic trigger of diffuse hair loss (telogen effluvium).

Put supplements in the right frame

The sober conclusion: correct a demonstrated deficiency, and you can see a noticeable improvement. If you have no deficiency, the solution is not on the supplement shelf. And if you have hereditary hair loss, supplements belong as a support, not as the treatment itself.

If you are in doubt about what is driving your hair loss, start with the overview of the different types of hair loss and a blood test at your doctor.

Marketing vs. evidence

Shelf after shelf of "hair vitamins" promises fuller hair, but most rest on weak or no evidence in people without a deficiency. Biotin is the classic example: the advertising highlights it, but genuine Biotin deficiency is rare, and supplements only benefit the few who really are lacking it.

Be aware, too, that large doses of selenium or vitamin A can paradoxically worsen hair loss. The rule is targeted supplementation after a blood test, not broad-spectrum pills "just in case". See the documented options in their proper context in Slowing hair loss without surgery.