Diet and hair loss: effects of nutrient deficiency and supplement use

Abstract

Patients presenting with hair loss should be screened by medical history, dietary history and physical exam for risk factors for nutrient deficiency. If warranted, laboratory studies may be performed. In patients with no risk factors, further laboratory evaluation searching for nutritional deficiencies is not warranted. For patients with nutritional deficiencies, it is clear that those deficiencies should be corrected. Further research is required to determine whether any benefit exists for nutrient supplementation in the absence of documented deficiency. At this time, patients must be informed that such research is lacking and that in fact some supplements carry the risk of worsening hair loss or the risk of toxicity.

Full text

Review | Dermatol Pract Concept 2017;7(1):1 1
DERMATOLOGY PRACTICAL & CONCEPTUAL
www.derm101.com
Introduction
Patients with hair loss often inquire whether nutritional
supplements can help restore hair growth or prevent further
hair loss. In fact, many will start dietary supplements with-
out consultation in the hope that the supplements will help.
The unregulated supplement industry also capitalizes on this
population’s vulnerability. While hair follicles are among the
most metabolically active in the body, and hair growth may
be impacted by calorie and protein malnutrition as well as
micronutrient deficiency, the links are complex.
Nutritional deficiency may impact both hair structure
and hair growth. Effects on hair growth include acute telogen
effluvium (TE), a well-known effect of sudden weight loss or
decreased protein intake [1], as well as the diffuse alopecia
seen in niacin deficiency [2]. Studies have also reported poten-
tial associations between nutritional deficiency and chronic
TE, androgenetic alopecia (AGA), female pattern hair loss
(FPHL), and alopecia areata (AA) [3,4].
Given this well-recognized link, many patients seeking
treatment for hair loss ask about dietary recommendations.
Specifically, is it necessary to test for nutrient deficiency in a
patient presenting with hair loss? Are there risk factors that
should prompt testing? In the absence of such risk factors,
is there any evidence to support the use of micronutrient
supplementation?
Physicians must be prepared to answer these questions.
Hair loss is common, with close to 50% of men and women
Diet andhair loss: effects of nutrient deficiency
and supplement use
Emily L. Guo1, Rajani Katta2
1 Baylor College of Medicine, Houston, TX, USA
2 Department of Dermatology, Houston Methodist Hospital, Houston, TX, USA
Key words: hair loss, alopecia, diet, nutrition, supplementation
Citation: Guo EL, Katta R. Diet andhair loss: effects of nutrient deficiency and supplement use. Dermatol Pract Concept. 2017;7(1):1.
DOI: http://dx.doi.org/10.5826/dpc.0701a01
Received: August 16, 2016; Accepted: November 25, 2016; Published: January 31, 2017
Copyright: ©2017 Guo et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: None.
Competing interests: The authors have no conflicts of interest to disclose.
All authors have contributed significantly to this publication.
Corresponding author: Rajani Katta, MD, 6800 West Loop South, Suite 180, Bellaire, TX 77401, USA. Tel. 281-501-3150; Fax. 832-810-
0072. Email: info@kattamd.com
Patients presenting with hair loss should be screened by medical history, dietary history and physical
exam for risk factors for nutrient deficiency. If warranted, laboratory studies may be performed. In
patients with no risk factors, further laboratory evaluation searching for nutritional deficiencies is
not warranted. For patients with nutritional deficiencies, it is clear that those deficiencies should be
corrected. Further research is required to determine whether any benefit exists for nutrient supple-
mentation in the absence of documented deficiency. At this time, patients must be informed that such
research is lacking and that in fact some supplements carry the risk of worsening hair loss or the risk
of toxicity.
ABSTRACT

2 Review | Dermatol Pract Concept 2017;7(1):1
Vegans and vegetarians are also at higher risk for ID, as
their requirements for dietary iron are considered to be 1.8
times higher than for meat consumers [18]. Non-heme iron,
found in plants, has a lower bioavailability than heme iron,
found in meat and fish [19].
Patients with more advanced ID develop iron deficiency
anemia and require replacement. ID may also result in a
reduction of storage iron, measured by serum ferritin. A
normal ferritin level does not exclude ID, however, as it is an
acute phase reactant.
Although multiple research studies have been conducted,
it is unknown if a deficiency of storage iron contributes to
hair loss, as conflicting results have been noted. Some stud-
ies have found that low serum ferritin is more prevalent in
patients with chronic TE, FPHL, AGA, and AA. Other studies
have found no such link. Two excellent review articles have
summarized these results and note considerable variations in
study design, controls, and ID definitions [16,20]. There are
few intervention trials, and they are limited by small numbers,
lack of controls in some, and variable ferritin levels. These
have utilized different interventions, including iron alone [21],
iron with L-lysine [8,22], and iron with spironolactone [23].
One study used a control population that excluded
patients at risk for ID [24] and found no statistically signifi-
cant increase in the prevalence of ID in premenopausal or
postmenopausal women with chronic TE or FPHL.
At this time, there are no definitive answers. Patients must
be approached on a case-by-case basis. In the aforementioned
review articles, the researchers present their approach. Both
groups test patients with iron studies, including serum ferritin.
Both recommend treatment of ID, with or without anemia,
with dietary sources and oral iron supplementation when
necessary, with a goal of ferritin levels above 50 μg/L [16] or
70 μg/ml, respectively [20].
Patients are monitored to measure their response—an
important point. Patients who take iron supplements without
monitoring are at risk for potentially severe complications,
as iron supplementationleading toiron overload can cause
toxicity. This can occur even at low levels if taken over a long
period [25].
Zinc
Zinc is an essential mineral required by hundreds of enzymes
and multiple transcription factors that regulate gene expres-
sion [26]. While the exact mechanism of action is unclear, one
possibility centers on zinc’s role as an essential component
of numerous metalloenzymes important in protein synthesis
and cell division [27]. Another possibility is zinc’s role in the
Hedgehog signaling pathway [28], a critical component in
the pathways that govern hair follicle morphogenesis [29].
Zinc deficiency may be either inherited or acquired and
affected by pattern hair loss by age 50 [5]. Many nutritional
supplements are marketed as hair loss treatments. A search
of the keywords “hair loss” within the Vitamins & Dietary
Supplements section of Amazon.com, which sells supple-
ments via Internet sales, yields 923 products [6]. Many are
composed of differing formulations. The U.S. Food and Drug
Administration (FDA) does not have the authority to review
dietary supplements for safety and effectiveness before they
are marketed, and it is therefore the responsibility of manu-
facturers [7].
Given the marketing efforts directed to consumers, physi-
cians must be able to respond with a review of the known
evidence. One point to emphasize is that such supplements are
not without risks. In the absence of deficiency, supplementation
may actually prove harmful to hair. Over-supplementation of
certain nutrients, including selenium, Vitamin A, and Vitamin
E, has actually been linked to hair loss [4,8-11]. It is therefore
surprising that the best-selling hair supplement on Amazon.
com contains both vitamin A and vitamin E [12], while the next
contains selenium, vitamin A, and vitamin E [13].
While such products contain a variety of nutrients, review
of the medical literature finds a notable lack of evidence sup-
porting their use. Much of what is known about nutrient effect
on hair loss is based on disease states that result in deficiency.
There is currently a lack of literature regarding the effects of
supplementation in individuals without nutrient deficiency. In
this paper, we review the available literature on nutrient defi-
ciencies that result in hair loss, detail the risk factors for these
deficiencies, and review the available evidence of the effects
of supplementation, both beneficial and adverse, on hair loss.
Iron
Iron deficiency (ID) is the world’s most common nutritional
deficiency and is a well-known cause of hair loss. What remains
unclear is what degree of ID may contribute to hair loss.
While the mechanism of action by which iron impacts
hair growth is not known, hair follicle matrix cells are some
of the most rapidly dividing cells in the body, and ID may
contribute to hair loss via its role as a cofactor for ribonucleo-
tide reductase, the rate-limiting enzyme for DNA synthesis
[14]. In addition, multiple genes have been identified in the
human hair follicle [15], and some may be regulated by iron
[16]. In a mouse model, reversal of ID led to restoration of
hair growth [17].
Certain populations are at higher risk for ID, and a medi-
cal and dietary history may reveal risk factors. Premenopausal
women are at higher risk due to menstrual blood loss, while
postmenopausal women and men may present due to gastro-
intestinal blood loss. Other risk factors include malabsorption
disorders (such as celiac disease) as well as achlorhydria or the
use of H2 blockers, as iron requires an acidic pH for absorption.

Review | Dermatol Pract Concept 2017;7(1):1 3
In a review of the literature, no studies regarding niacin
levels in patients presenting only with hair loss were identified.
Fatty Acids
Deficiency of the polyunsaturated essential fatty acids linoleic
acid (an omega-6 fatty acid) and alpha-linolenic acid (an
omega-3 fatty acid) can result from inappropriate parenteral
nutrition and malabsorption disorders such as cystic fibrosis.
Hair changes include loss of scalp hair and eyebrows as well
as lightening of hair [3,4]. Unsaturated fatty acids may modu-
late androgen action by inhibition of 5α-reductase, similar to
the drug finasteride [42]. Additionally, arachidonic acid, an
omega-6 fatty acid, may promote hair growth by enhancing
follicle proliferation [43].
However, limited information is available on supplemen-
tation. In one patient with essential fatty acid deficiency, topi-
cal application of safflower oil, high in linoleic acid, resulted
in growth of hair [44].
While results from a trial utilizing a supplement were
reported, limited conclusions may be drawn, as this supple-
ment combined multiple fatty acids and antioxidants [45].
Selenium
Selenium is an essential trace element that plays a role in
protection from oxidative damage as well as hair follicle
morphogenesis. Rats deficient in selenium display sparse hair
growth [46], while knockout mice lacking specific selenopro-
teins exhibit progressive hair loss after birth [47].
Risk factors for deficiency include living in areas with low
selenium soil content (particularly in parts of China, Tibet,
and Siberia), long-term hemodialysis, HIV, and malabsorption
disorders [48].
There is limited research on selenium deficiency and alo-
pecia in humans. One case report in a child described sparse
hair, which improved after dietary supplementation [49].
Given the lack of human research, it is surprising that
some hair loss supplements are marketed as containing
selenium. This is concerning, as selenium toxicity from nutri-
tional supplementation is well documented [9-11].Toxicity
can result in generalized hair loss, as well as blistering skin
lesions, gastrointestinal symptoms, and memory difficulties.
Vitamin D
Data from animal studies suggests that vitamin D plays a role
in hair follicle cycling [50]. In a study of mice treated to model
vitamin D-dependent rickets, the resultant animals developed
hair loss [51]. In vitro studies have shown increase in vitamin
D receptor expression in the outer root sheath keratinocytes
during the growing phases of the hair cycle [52].
may affect multiple organ systems. Patients may experience
diarrhea, immunological effects, and delayed wound healing.
Abnormalities in taste and smell may occur. Cutaneous effects
include acral and periorificial dermatitis, while hair changes
include TE and brittle hair.
The autosomal recessive disorder, acrodermatitis entero-
pathica, results in decreased absorption of zinc, while acquired
zinc deficiency may occur in malabsorption syndromes, such
as inflammatory bowel disease [30] or following gastric
bypass surgery. Other groups at risk include patients with
malignancy, those with liver or renal dysfunction, pregnant
women [31], and patients with alcoholism [32]. Drugs that
can affect zinc levels include valproic acid [33] and certain
antihypertensives [34].
Dietary risk factors include vegetarianism, as bioavail-
ability of zinc is lower in vegetables than meat [35]. Addition-
ally, vegetarians typically consume more legumes and whole
grains, which contain phytates that bind to zinc and inhibit
absorption [35].
Serum zinc, the most commonly measured index of zinc
status, may be impacted by several variables, and the func-
tional effects of deficiency may be observed before serum
levels decrease below normal [36].
Screening in those with risk factors is indicated, as hair
loss due to zinc deficiency can be reversed. A case series dem-
onstrated reversal of hair loss following oral supplementation
in five patients with TE and zinc deficiency [37].
A study of 312 patients with AA, male pattern hair loss
(MPHL), FPHL, or TE showed that all groups had statistically
lower zinc concentrations as compared to 30 healthy controls
[38]. In patients with AA and low serum zinc levels, supple-
mentation has been shown to have therapeutic effects [39].
However, there is currently limited information on the
effects of zinc supplementation on hair growth in those
without documented deficiency. One report described a single
patient with alopecia, without clear deficiency, who experi-
enced improvement following oral zinc therapy [40].
A major point when considering supplementation in the
absence of known deficiency is that zinc toxicity can occur
with excess supplementation. Acute adverse effects include
pain, vomiting, and diarrhea, while chronic effects include
interaction with iron and reduced immune function [18].
Niacin
Pellagra, due to a deficiency of niacin, results in the well-
known triad of photosensitive dermatitis, diarrhea, and
dementia. Alopecia is another frequent clinical finding [2].
Pellagra became rare in many developed countries after
niacin fortification of food was introduced. Alcoholism is
now considered the most common cause of pellagra in devel-
oped countries [41]. Other causes include malabsorption
disorders or drug-induced cases, such as with isoniazid [41].

4 Review | Dermatol Pract Concept 2017;7(1):1
No significant difference in serum folate levels was seen
in 91 patients with diffuse hair loss as compared to controls
[58]. In fact, another study of 200 women with chronic TE
showed 28.5% had elevated serum folic acid, although meth-
odology of the study was not included and therefore limited
conclusions may be drawn [8].
Biotin
Biotin, or vitamin H, serves as a cofactor for carboxylation
enzymes. In isolated sheep hair follicles, incubation in biotin-
containing solutions resulted in increased DNA concentration
and protein synthesis [59].
Symptoms of deficiency include eczematous skin rash, alo-
pecia, and conjunctivitis [60]. One study of an infant fed with
a formula lacking sufficient biotin content reported manifesta-
tions of periorificial dermatitis and patchy alopecia, both of
which resolved with daily oral supplementation of biotin [61].
Biotin deficiency is rare, as intestinal bacteria are typically
able to produce adequate levels of biotin. Deficiency is seen
in cases of congenital or acquired biotinidase or carboxylase
deficiency, antibiotic use disrupting the gastrointestinal flora,
and antiepileptic use. Deficiency can occur from excessive
ingestion of raw egg whites due to binding by avidin.
No clinical trials have shown efficacy in treating hair loss
with biotin supplementation in the absence of deficiency.
Despite this, biotin is found in multiple supplements marketed
to consumers for hair loss. This marketing approach may
have been chosen as biotin has shown positive effects in the
treatment of brittle fingernails and onychoschizia [62-63].
Amino Acids and Proteins
Protein malnutrition, such as in kwashiorkor and marasmus,
can result in hair changes that include hair thinning and hair
loss [64].
One study examined the role of L-lysine, an essential
amino acid that may play a role in iron and zinc uptake.
Addition of L-lysine to iron supplementation resulted in a
significant increase in mean serum ferritin concentration
in some women with chronic TE who failed to respond to
iron supplementation alone [8]. Although interesting, there
is limited data available, and the role of L-lysine should be
investigated further.
In terms of other amino acids and proteins, no clear con-
clusions may be drawn about the role of supplementation in
hair loss. While trials of amino acid and protein supplements
have been published, they are formulated with a variety of
nutrients, and therefore it is unclear what role, if any, is played
by amino acid and protein supplementation in the absence of
known deficiency.
Risk factors for vitamin D deficiency include inadequate
sun exposure, dark skin, obesity, gastric bypass, and fat mal-
absorption [53].
One study of eight females with TE or FPHL showed
that serum vitamin D2 levels were significantly lower than
in controls. Furthermore, vitamin D2 levels decreased with
increased disease severity [54]. However, data on the effects
of vitamin D supplementation in hair loss is lacking.
Vitamin A
Vitamin A is a group of compounds including retinol, retinal,
retinoic acid, and provitamin A carotenoids. In murine stud-
ies, dietary vitamin A has been shown to activate hair follicle
stem cells [55], although its role is recognized as complex and
“precise levels of retinoic acid are needed for optimal function
of the hair follicle” [56].
While deficiency has not been linked to hair loss, high
levels of vitamin A have. In fact, one study found that in a
mouse AA model, reduction of vitamin A in the diet actually
delayed hair loss onset [56].
In humans, hypervitaminosis A may result from over-
supplementation and has a strong known link to hair loss
with other effects such as skin, vision, and bone changes [4,8].
Vitamin E
Tocotrienols and tocopherols are members of the vitamin
E family and are potent antioxidants. Deficiency results in
hemolytic anemias, neurologic findings, and skin dryness.
Vitamin E deficiency is rare, but may occur with fat malab-
sorption disorders.
Minimal information in the literature exists regarding
benefits of vitamin E supplementation on hair loss. One study
of 21 volunteers who received tocotrienol supplementation
(100 mg of mixed tocotrienols daily) showed significant
increase in hair number as compared to a placebo group [57].
However, excess supplementation may result in hyper-
vitaminosis E, which can increase the risk of bleeding and
decrease thyroid hormone production. Additionally, there is
some evidence for an adverse effect on hair growth, as seen
in volunteers taking 600 IU per day for 28 days, a dosage
around 30 times the daily recommended intake [8]. This
group had significant decreases in thyroid hormone levels [8].
Folic Acid
Folic acid is found in leafy greens and many foods are forti-
fied with folic acid, making deficiency uncommon. Deficiency
mainly results in megaloblastic anemia, without manifesta-
tion of hair loss.

Review | Dermatol Pract Concept 2017;7(1):1 5
TABLE 1. Effects of nutrient deciency and supplement use on hair loss. [Copyright: ©2017 Guo et al.]
Nutrient Effect of Deciency on Hair Loss Studies of Supplementation
Iron • Chronic diffuse telogen hair loss with iron
deciency anemia [20].
• In the absence of anemia, studies are not clear
whether there is a signicant link between ID
and hair loss [16,20,24].
• Insufcient evidence to recommend iron
supplementation to all hair loss patients with
iron deciency in the absence of anemia [20].
Approach on a case-by-case basis.
• Excess supplementation can cause
hemochromatosis [25].
Zinc • Statistically lower serum zinc concentrations
in a study of 312 patients with AA, MPHL,
FPHL, or TE compared to 30 healthy controls
[38].
• A case series demonstrated reversal of hair
loss following oral supplementation in ve
patients with TE and zinc deciency [37].
• Limited information on effects of zinc
supplementation improving hair growth in the
absence of deciency.
• One case report with a patient with dry
brittle hair and alopecia, without clear zinc
deciency, who experienced improvement in
alopecia following oral zinc therapy [40].
• Excess supplementation can cause acute toxic
effects including epigastric pain, nausea,
vomiting diarrhea, and headache and chronic
toxic effects including reduced copper status,
interaction with iron, reduced immune
function, and decreased concentrations of
HDL cholesterol [18].
Niacin (Vitamin B3) • Diffuse hair loss with pellagra due to severe
deciency [2].
• No known studies regarding serum niacin
levels in patients with hair loss.
• Limited information on effects of niacin
supplementation improving hair growth in
absence of deciency.
Fatty acids • Loss of scalp and eyebrow hair [3-4]. • Limited information on effects of fatty acid
supplementation improving hair growth in
absence of deciency.
Selenium • In animal studies, rats decient in selenium
display sparse hair growth [46], while
knockout mice lacking specic selenoproteins
exhibit progressive hair loss after birth,
ultimately leading to almost total alopecia
[47].
• One case report of selenium deciency in a
young child reported clinical manifestations
of dry skin and sparse, light-colored hair,
improving after supplementation [49].
• Limited information on effects of selenium
supplementation improving hair growth in
absence of deciency.
• Toxicity from excess supplementation is well
documented and can cause generalized hair
loss [9-11].
Vitamin D • Serum vitamin D2 levels in a study of eight
females with either TE or FPHL were shown
to be signicantly lower than in 40 age-
matched female controls, with decreased levels
correlating to increased disease severity [54].
• Limited information on effects of vitamin D
supplementation improving hair growth in
absence of deciency.
Vitamin A • Deciency has no known link to hair loss. • Limited information on effects of vitamin A
supplementation improving hair growth in
absence of deciency.
• Toxicity from excess supplementation has
a strong known link to hair loss, as well as
other effects on skin, vision, and bone [4,8].
(Continued next page)

6 Review | Dermatol Pract Concept 2017;7(1):1
oxidative stress may have an important role in the balding
phenotype and development of AGA [72]. Additionally, in a
study of endogenous antioxidant enzymes and lipid peroxida-
tion in the scalps of patients with AA, excessive free radical
generation was shown to occur in the scalps of patients with
AA accompanied by high levels of antioxidant enzymes that
were unable to protect against the ROS [73].
While dietary antioxidants play a key role in reinforcing
our endogenous antioxidant system, high doses of exogenous
antioxidants may actually disrupt the balance between oxida-
tion and antioxidation [71]. In vitro studies have shown that
while polyphenols have antioxidant properties at low concen-
trations, they can potentiate ROS generation at higher concen-
trations [71, 74-75]. Compounds within plant foods, such as
from fruits, vegetables, and grains, may be safer and healthier
compared to isolated, high doses present in supplements [71].
Conclusion
While multiple nutrient deficiencies may result in hair loss
(Table 1), screening for such deficiencies must be guided by the
One trial included L-cysteine, a constituent of keratin, in
combination with medicinal yeast and pantothenic acid [65].
Other trials have evaluated supplements containing marine
proteins in conjunction with multiple other nutrients [66-69].
However, it is difficult to evaluate the results of these trials,
as the composition of thesenutritionalsupplements is not
disclosed. Marketing materials accessed from one product’s
website describe the composition as including “vitamins and
minerals forhairgrowth, including iron, zinc, biotin, niacin,
vitamin C and an exclusive marine complex derived from
fish proteins” [70].
Antioxidants
Antioxidants are compounds that are able to neutralize reac-
tive oxygen species (ROS), preventing oxidative damage.
Many substances can be classified as antioxidants, including
zinc, selenium, and vitamins A and E, as described previously
in this article, as well as vitamin C and polyphenols [71]. Oxi-
dative stress has been linked to hair loss. In vitro studies of
dermal papilla cells from male AGA patients have shown that
TABLE 1. (continued)
Nutrient Effect of Deciency on Hair Loss Studies of Supplementation
Vitamin E • Deciency has no known link to hair loss. • Limited information on effects of vitamin E
supplementation improving hair growth in
absence of deciency.
• Supplementation in one study of twenty-one
volunteers suffering from hair loss has showed
signicant increase in hair number compared
to placebo [57].
• Toxicity from excess supplementation can
result in risk of bleeding problems, decreased
thyroid hormones, and decreased activity of
vitamin K. Additionally, there is some evidence
for adverse effect on hair growth with excess
supplementation [8].
Folic Acid • No signicant difference in serum folate levels
in a study of 91 patients with diffuse hair loss
and 74 healthy controls [58].
• Limited information on effects of folic acid
supplementation improving hair growth in
absence of deciency.
Biotin • Deciency can result in alopecia, eczematous
skin rash, conjunctivitis, and candidiasis [60].
• Limited information on effects of biotin
supplementation improving hair growth in
absence of deciency.
Amino Acids and
Proteins
• Protein malnutrition can result in hair loss
[64].
• L-lysine supplementation in addition to
iron supplementation has been shown to
signicantly increase mean serum ferritin
concentration in some women with
chronic TE who failed to respond to iron
supplementation alone [8].
• Limited information on effects other amino
acids and proteins improving hair growth in
absence of deciency.
Key of abbreviations: Alopecia areata – AA; Androgenic alopecia – AGA; Female pattern hair loss – FPHL; High density lipoprotein
– HDL; Iron deciency – ID; Male pattern hair loss – MPHL; Telogen euvium - TE.

Review | Dermatol Pract Concept 2017;7(1):1 7
history and physical exam. Nutrient deficiencies may arise due
to genetic disorders, medical conditions, or dietary practices.
If risk factors are identified (Table 2), then laboratory
screening for nutrient deficiency may be indicated. In patients
with hair loss, but without any known risk factors for nutri-
ent deficiency, laboratory testing for nutrient deficiency is
not required.
An area that requires further research is the role of supple-
mentation. It is clear that nutrient deficiencies must be cor-
rected. What is unclear is the ideal range of micronutrient
levels to prevent or correct hair loss. In ID and anemia, sup-
plementation is required, but patients with ID in the absence
of anemia must be approached on a case-by-case basis. Some
authors believe that raising levels of storage iron may improve
hair loss, although the research is not conclusive. All patients
receiving iron supplementation must be monitored due to
toxicity risk.
For other nutrients, such as zinc, supplementation in
deficient patients has resulted in hair growth, although, again,
patients must be monitored due to toxicity risk (Table 3).
There is very limited research on the role of nutrient
supplementation in the absence of deficiency. Despite this,
patients often seek nutrient supplements as a treatment for
hair loss. In fact, direct-to-consumer advertising promotes the
use of supplements for hair loss, and many such products,
containing a wide variety of formulations, are easily avail-
able for purchase.
TABLE 2. Medical and dietary history risk factors that can cause nutritional
deciencies contributing to hair loss. [Copyright: ©2017 Guo et al.]
Medical or Dietary History Risk Factor Nutrient Deciency
History of blood loss (menstrual in
premenopausal women, GI in postmenopausal
women and men)
Iron
Malabsorption disorders Multiple vitamin deciencies
Pregnancy Iron, folic acid, zinc
Alcoholism Folic acid, zinc, niacin
Malignancy Iron, zinc, can depend on type of malignancy
Renal dysfunction Selenium, zinc
H2 blocker use Iron
Antiepileptics Biotin, Zinc
Antihypertensives Zinc
Prolonged antibiotic use Biotin
Isoniazid Niacin
Inadequate sun exposure Vitamin D
Living in parts of China, Tibet, and Siberia Selenium
Vegans/vegetarians Iron, zinc
Excessive ingestion of raw egg whites Biotin
Malnutrition Multiple vitamin deciencies
TABLE 3. Potential toxicities of supplements.
[Copyright: ©2017 Guo et al.]
Supplement
in Excess Signs and Symptoms of Toxicity
Iron Acute
• GI bleeding
• Abdominal pain
• Metabolic acidosis
Chronic
• Hemochromatosis
Zinc Acute
• Abdominal pain
• Vomiting
• Diarrhea
Chronic
• Interaction with iron
• Immune dysfunction
Selenium • Hair loss
• Blistering skin lesions
• Gastrointestinal symptoms
• Memory difculties
Vitamin A • Hair loss
• Skin, vision, and bone changes
• Increased intracranial pressure
Vitamin E • Increased risk of bleeding
• Decreased thyroid hormone
production
• Possible adverse effect on hair growth

8 Review | Dermatol Pract Concept 2017;7(1):1
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Physicians must counsel their patients on the lack of
research supporting these products. Since supplements are
not regulated by the FDA, it is up to the physician and the
consumer to review the efficacy and safety of supplements.
Websites such as the Natural Medicines Comprehensive
Database [76] or the National Institutes of Health Office of
Dietary Supplements’ PubMed Dietary Supplement Subset
[77] and Dietary Supplements Ingredient Database [78]
may be of help in this exploration. Equally important is a
discussion of the potential toxicity of some of these supple-
ments. Over-supplementation of some nutrients may result
in multiple toxicities, while over-supplementation of certain
nutrients, including vitamin A, vitamin E, and selenium, may
actually result in hair loss.
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