Not all hair loss is a vitamin problem: read this before buying supplements

Many people start buying iron, zinc, biotin or vitamin D on their own as soon as their hair starts falling. But not all hair loss comes from a vitamin deficiency, and a supplement helps most only when there really is a deficiency — not just because you have hair loss.

Your body sometimes warns you

Sometimes, before a lab result is in, the body gives warning signs such as:

• tiredness and weakness
• brittle nails
• dry skin

These don't mean you definitely have a deficiency, but they're a sign that it's worth checking.

What does the evidence say?

A review in Dermatology and Therapy looked at the role of vitamins and minerals such as iron, zinc, vitamin D and the B vitamins in hair loss. It found that deficiencies can play a part in hair loss and can be corrected — but evidence for supplements in people without a deficiency is limited and conflicting.

Why not self-medicate?

• Without a deficiency, a supplement usually won't improve hair loss.
• Too much of some nutrients, such as vitamin A or selenium, can itself cause hair loss.
• Biotin, found in high doses in many hair, skin and nail supplements, can falsely change some blood-test results — including thyroid tests and the heart test troponin. The U.S. FDA has issued a warning about this.

The right first step

• First find the cause of the hair loss: its pattern, medical history, medicines, diet, stress and hormonal changes.
• If needed, the doctor orders tests such as a full blood count, ferritin (iron stores), thyroid tests and vitamin D.
• If a deficiency is found, the right supplement is prescribed at a set dose and for a set time, then rechecked.

References

• Almohanna HM, Ahmed AA, Tsatalis JP, Tosti A. The Role of Vitamins and Minerals in Hair Loss: A Review. Dermatology and Therapy, 2019 — pmc.ncbi.nlm.nih.gov/articles/PMC6380979
• U.S. Food and Drug Administration. UPDATE: The FDA Warns that Biotin May Interfere with Lab Tests (Safety Communication), 2019 — fda.gov/medical-devices/safety-communications/update-fda-warns-biotin-may-interfere-lab-tests-fda-safety-communication