Nearly half of all British adults take a vitamin or supplement weekly, according to a recent YouGov survey. While supplements can support overall health—particularly when paired with a balanced diet—experts warn that excessive intake of certain nutrients may harm hair health.
Dr Ali, a hair-loss specialist, cautions that high doses of popular supplements can trigger telogen effluvium, a temporary condition in which more hair than usual enters the shedding phase.
“Supplements aren’t harmless just because they’re available over the counter,” Dr Ali explains. “In excessive amounts, some can disrupt the hair cycle, leading to increased shedding, brittleness, and breakage.”
Supplements to Watch
Certain nutrients, when consumed in excess, have been linked to hair shedding and other side effects:
- Selenium: Often included in hair-growth formulas and valued for immune support, too much selenium can irritate hair follicles. Dr Ali notes, “Excess selenium may cause brittle strands, patchy thinning, and toxicity signs such as nausea, vomiting, and nail discoloration.”
- Vitamin E: Present in seeds, nuts, and plant oils, the recommended daily allowance is about 15mg for adults. “While vitamin E benefits hair in appropriate doses, over-supplementation has been associated with increased shedding in some individuals,” Dr Ali warns.
- Zinc: Essential for immune function and cell growth, zinc is frequently found in hair-loss remedies. “Your body can’t make zinc naturally, but high intake over time may worsen hair loss rather than prevent it. Maintaining balance is key,” advises Dr Ali.
- Vitamin A: Vital for vision and skin health, excessive Vitamin A is a known contributor to hair loss. Dr Ali adds, “Over-supplementation can also cause vomiting, dizziness, and blurred vision.”
Protecting Your Hair and Health
Experts emphasize a measured approach to nutrition:
- Prioritize food first: Aim to meet nutrient needs through a varied, balanced diet whenever possible.
- Check labels and totals: Consider all sources of a nutrient, including multivitamins, single supplements, and fortified foods, to avoid toxicity.
- Avoid mega-doses: More is not always better—high doses of supplements are not a shortcut to healthier hair.
- Test before supplementing: If you’re concerned about deficiencies or hair loss, consult a clinician for blood tests before taking large doses.
Hair loss can result from stress, illness, hormonal changes, medications, and supplements. “Vitamins and minerals can support healthy hair—but stick to evidence-based doses and seek personalised guidance before combining multiple supplements,” Dr Ali concludes.
