Minerals for Hair, Skin and Nails: Iron, Zinc, Selenium, Silica and What Evidence Exists

What the research found

1. Iron

   Mixed

   Women with nonscarring hair loss had lower ferritin values in a meta-analysis; this compares levels, it is not a supplement trial [3]

2. Zinc

   Insufficient evidence for supplements

   People with alopecia areata had lower serum zinc than controls [4]

3. Selenium

   Evidence of harm at high amounts

   Too much causes hair and nail loss [5]

4. Silica

   Insufficient evidence

   One small trial reported less hair and nail brittleness compared with baseline [6]

Hair loss and the role of status

The NHS lists iron deficiency among causes of temporary hair loss, alongside illness, stress, cancer treatment and weight loss. [2] Pattern baldness is a different, permanent type that usually runs in the family. [2] It advises seeing a GP to find the cause before thinking about a commercial hair clinic. [2]

A review of vitamins and minerals in hair loss says deficiency may be a modifiable risk factor, and that large double-blind placebo-controlled trials are required to determine the effect of supplementation on hair growth. [1]

Iron

A systematic review pooled 36 studies (10,029 participants) and found women with nonscarring alopecia had lower ferritin values than women without it. [3] The review itself opens by saying there is no clear-cut evidence in the literature of an association between iron deficiency and nonscarring alopecia. [3] Whether iron pills regrow hair in women with low ferritin is not answered by this study. Iron testing and deficiency are covered at anemia and iron deficiency. Very high iron doses can be fatal, particularly in children, so keep iron out of reach. [7]

Zinc

A 2025 meta-analysis of 34 papers (4,931 participants from 16 countries) found people with alopecia areata had lower serum zinc than controls, with no difference in copper. [4] Lower levels in people with the condition do not show that supplements treat it. The meta-analysis describes alopecia areata as a prevalent autoimmune disorder. [4] It needs medical evaluation: alopecia areata and scarring hair loss. The NHS says do not take more than 25 mg of zinc supplements a day unless a doctor advises it, as high doses reduce copper absorption. [5]

Selenium

The NHS says too much selenium causes selenosis, which in its mildest form can lead to loss of hair and nails, and that 350 mcg or less a day of supplements is unlikely to cause harm for adults in the UK. [5] Hair products that contain selenium deserve a label check: selenium toxicity.

Silica for nails, hair and skin

In a randomized trial, 50 women with photodamaged facial skin took 10 mg of silicon a day (as choline-stabilized orthosilicic acid) or placebo for 20 weeks. [6] Hair and nail brittleness scores, which women rated themselves, were significantly lower after 20 weeks than at baseline in the silicon group. [6] A 2025 review of nail supplements says choline-stabilized orthosilicic acid has been shown to improve the look, strength and brittleness of nails, and notes that manufacturers are not required to carry out efficacy and safety studies before marketing. [8] We label this insufficient evidence: small, self-rated, one product type. See silica claims checked.

Skin

Beyond the silica trial, Proper evidence not found for mineral supplements and skin in the sources we read. We searched PubMed for oral supplements, hair, nails and silicon. For skin basics see nutrition for skin and hair.

Official levels (UK, adults 19 to 64, NHS, 2020)

US and EU figures differ, and we could not read US National Institutes of Health fact sheets this session.