A hairy connection
Everyone seems to love and strives to have a healthy and spectacular set of hair to show off or enjoy running fingers through. People with Hashimoto’s, like myself, usually have to put an extra bit of effort to have a decent looking hair. That is because our immune system, besides tampering with our thyroid and gut, also tampers with our hair follicles. Zinc, known to affect both the thyroid and the immune system, might be one of the culprits and solutions to our hair troubles.
Zinc is a mineral, also known as a trace element, and is vital for a healthy hair. Zinc affects production of hormones. But, hormones also influence how will the body process zinc, creating a vicious cycle: if there is not enough of one, the other one will suffer too (1).
Zinc as an essential mineral is not only needed for a healthy hair, but is involved in and needed for more than 200 processes going on in our bodies (2). One of these processes is thyroid hormone metabolism, and zinc is found to be lower than normally expected in people with an underactive thyroid.
Besides thyroid condition, there are some other causes of zinc deficiency, such as malnutrition, problems with food absorption, chronic conditions (such as IBS or chronic kidney conditions), alcoholism, use of certain medications or it may be inherited (3).
Overall, zinc deficiency can cause lack of appetite, weight loss, slowdown of growth, amenorrhea (absence of menstrual period), hair loss, diarrhea, recurring infections, delayed wound healing, changes in taste and low insulin levels (3–6).
People eating predominantly plant based diet have a higher risk of zinc deficiency, because zinc is found in lower amounts in vegetables than in meat (7), also, people consuming large amounts of legumes or whole grains, containing chemicals called phytates that block zinc function have an increased risk of zinc deficiency (7).
Zinc over supplementation has a risk of resulting in zinc toxicity, with symptoms such as pain, vomiting and diarrhea (8).
Zinc and thyroid
Zinc is connected to thyroid function in more than one way: if low, TSH will not be made and this will result in low levels of thyroid hormones T4 and T3 (9).
Zinc is also an essential part of an enzyme deiodinase, which converts T4 into a functional T3. If zinc is low or missing from the body, T3 cannot be made(9).
Also, low zinc levels correlate with the increased levels of autoimmunity, as seen by high amounts of anti-thyroid antibodies (TPO and Tg) in thyroid patients (10).
Zinc and hair loss
Zinc maintains health of hair follicles (11), and low zinc levels are connected to hair loss (12- 14).
Zinc might be the main, but it is not the only mineral or vitamin important for maintenance of healthy hair.
Lack of niacin (part of vitamin B3 complex) (15), selenium and vitamin D (16, 17) will result in hair loss. Lack of vitamin A (18, 19), as well as its over-supplementation may result in hair loss (20, 21). Over supplementation of vitamin E may result in hair loss (21) too. Lack of biotin (22, 23) and iron (24–26) may also cause hair loss.
Alopecia and Hashimoto’s
People with no hair — related conditions have between 80,000 and 120,000 hairs on their head, growing at a rate of about 1cm/0.4in per month (27). This hair growth occurs in a three-phase cycle:
Hair growth phase or anagen (3–6 years)
Transition from hair growth to resting or catagen (1–2 weeks)
Rest phase or telogen (2–4 months)
Hair falls out after telogen phase has completed (27). Any premature hair fallout may be caused by hormone imbalance, certain medications or the seasons (27, 28).
Alopecia areata (“baldness in a circle”) is a genetic condition (29), and can be caused by Hashimoto’s and some other autoimmune or inflammatory diseases (Graves’, eczema and vitiligo). What happens is that own immune cells come close to follicles, and “freeze” them, cause hair to fall out.
If you are experiencing excessive hair loss or alopecia you can discuss several treatment options with your doctor:
Zinc treatment, which should be safe, unless overdosed, so it is good to get a professional advice (30)
Corticosteroids, applied on the area in question, although their efficacy is not well established (31, 32)
Other treatments include: dithranol (used for treatment of psoriasis), immune suppressants, steroids or medications used to treat autoimmune conditions (31, 33, 34).
In summary, zinc is an essential mineral, is both involved with and affected by the thyroid function. It might help with Hashimoto’s — caused hair loss.
Zinc rich diet might be a good first step to see if hair will recover. One should be aware it is a long process, and it might take months before any changes become noticeable.
It’s good to talk to your doctor about possible side effects and contraindications before deciding on any treatment.
Nishi Y et al. Zinc metabolism in thyroid disease, 1980
Ogawa Y et al. Zinc and skin biology, 2016
Safai-Kutti S. Oral zinc supplementation in anorexia nervosa, 1990
Prasad AS. Clinical, endocrinologic, and biochemical effects of zinc deficiency, 1985
Prasad AS. Impact of the discovery of human zinc deficiency on health, 2009
Robertson RP et al. A role for zinc in pancreatic islet β-cell cross-talk with the α-cell during hypoglycaemia, 2011
Hunt JR. Bioavailability of iron, zinc, and other trace minerals from vegetarian diets. 2003
Institute of Medicine (US) Panel on Micronutrients. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc, 2001
Baltaci AK et al Opposite effects of zinc and melatonin on thyroid hormones in rats, 2004
Ertek S et al. Relationship between serum zinc levels, thyroid hormones and thyroid volume following successful iodine supplementation, 2010
Plonka PM et al. Zinc as an ambivalent but potent modulator of murine hair growth in vivo-preliminary observations, 2005
Arnaud J et al Zinc status in patients with telogen defluvium, 1995
Rushton DH. Nutritional factors and hair loss, 2002
Kil MS et al. Analysis of Serum Zinc and Copper Concentrations in Hair Loss, 2013
Spivak JL et al. Pellagra: an analysis of 18 patients and a review of the literature 1977
Amor KT et al. Does D matter? The role of vitamin D in hair disorders and hair follicle cycling, 2010
Li YC , et al. Targeted ablation of the vitamin D receptor: an animal model of vitamin D-dependent rickets type II with alopecia, 1997
Suo L et al. Dietary vitamin A regulates wingless-related MMTV integration site signaling to alter the hair cycle, 2015
Everts HB. Endogenous retinoids in the hair follicle and sebaceous gland, 2012
Finner AM. Nutrition and hair: deficiencies and supplements, 2013
Rushton DH. Nutritional factors and hair loss, 2002
Wolf B. Biotinidase Deficiency,1993
Fujimoto W et al. Biotin deficiency in an infant fed with amino acid formula 2005
Ohyama M et al. Characterization and isolation of stem cell-enriched human hair follicle bulge cells 2006
St Pierre SA et al. Iron deficiency and diffuse nonscarring scalp alopecia in women: more pieces to the puzzle 2010
Du X et al. The serine protease TMPRSS6 is required to sense iron deficiency 2008
Paus R et al. The biology of hair follicles, 1999
Courtois M, Loussouarn G, Hourseau S, Grollier JF. Periodicity in the growth and shedding of hair, 1996
Betz RC et al. Genome-wide meta-analysis in alopecia areata resolves HLA associations and reveals two new susceptibility loci, 2015
Peter C et al. Therapie der Alopecia areata mit Zinksulfat — eine placebokontrollierte Studie an 307 Patienten, 1996
Freyschmidt-Paul P et al. Alopecia areata Klinik, Pathogenese und rationale Therapie einer T-Zell-vermittelten Autoimmunerkrankung, 2003
Tosti A et al. Efficacy and safety of a new clobetasol propionate 0.05% foam in alopecia areata: a randomized, double-blind placebo-controlled trial, 2006
Messenger AG et al. British Association of Dermatologists’ guidelines for the management of alopecia areata, 2012
Wolff H. The Diagnosis and Treatment of Hair and Scalp Diseases, 2016