Table 1.

The role of micronutrients in non-scarring alopecia and premature graying of hair

Micronutrients	TE/AGA	AA	Premature hair graying	ACP outcome study grading
Vitamin D	Study results are conflicting, but most authors agree on supplementing vitamin D in patients with hair loss and vitamin D deficiency	Several studies showed an association between AA and low vitamin D levels Correction of vitamin D deficiency improves AA outcome and enhances response to treatment	Screening for deficiency and supplementation are recommended	Moderate in all studies
Vitamin C	Crucial in patients with hair loss associated with iron deficiency	Few studies, thereby precluding recommendations	Data are not available	Very low in AA studies
Vitamin E	Data not available	Conflicting data, thereby precluding recommendations	Data are not available	Moderate in AA studies
Iron/Ferritin	Most authors agree on iron supplementation in patients with iron or ferritin deficiency and hair loss	Iron deficiency reported in female patients, likely coincidental	Screening for deficiency and supplementation are recommended	Moderate in all studies
Zinc	Data are not homogenous and findings are too inconsistent to recommend screening	Most studies revealed low serum levels in AA Evidence-based information on efficacy of zinc supplementation in AA is lacking	Data are not available	Moderate in TE/AGA and AA studies
Selenium	Toxicity can cause hair loss. There are no data to recommend screening	No data to provide recommendations	Screening for deficiency and supplementation are recommended	Low in TE/AGA and premature graying of hair studies
Riboflavin	Deficiency can cause hair loss. Data are too scarce to recommend screening	Data are not available	Data are not available	Very low in TE/AGA studies
Biotin	Biotin levels can be low in patients complaining of hair shedding Efficacy of supplementation not supported by evidence-based trials Exogenous biotin interferes with some laboratory tests, creating false negative or false positive results	No studies on biotin as monotherapy	Data are not available	Low and very low in TE/AGA studies
Folic acid/Vitamin B12	Data are not sufficient to recommend screening and supplementation	A few studies suggest that the levels of folate or vitamin B12 might modify progression of AA Data are scarce for recommending supplementation	Screening for deficiency and supplementation are recommended	-Low in TE/AGA studies -Moderate in AA and in premature graying of hair studies
Vitamin A	Hypervitaminosis A causes hair loss Screening is recommended in selected cases	Data are not available	Data are not available	Low and very low in TE/AGA studies

AA alopecia areata, AGA androgenetic alopecia, TE telogen effluvium, ACP american college of physicians