Zinc is an essential micronutrient, having important functions in biochemical processes in the body. Zinc is essential for protein synthesis, nucleic acid synthesis, cellular functions and several enzymatic processes.
Zinc deficiency causesThe primary cause of deficiency is insufficient levels of the mineral in the diet. Another cause is inefficient uptake from the food, though the food may contain sufficient amounts of the mineral. Other causes are, genetic factors, malabsorption syndromes and increased gastrointestinal and urinary losses. Chronic liver disease, ulcerative colitis, chronic renal disease, Crohn’s disease, sickle cell disease, diabetes, short bowel syndrome, cancer, other chronic illnesses, gastrointestinal surgery and chronic diarrhea may also cause deficiency of the mineral.
Certain medications, minerals and chemicals may interact and affect its absorption and utilization. Quinolone antibiotics and tetracycline antibiotics affect the absorption of zinc in the intestine and thiazide diuretics increase its urinary excretory loss. High doses of iron and copper can affect the absorption of this mineral from the intestine.
Acrodermatitis enteropathica (Brandt syndrome or Danbolt–Closs syndrome) is a congenital metabolic disorder affecting the uptake of zinc. It is characterized by skin inflammation around the natural orifices and extremities, loss of hair and diarrhea.
Research on zinc deficiency hair lossIn a study carried out by Min Seong Kil et al. at Hallym University Kangdong Sacred Heart Hospital (Seoul, Korea), 312 patients with main complaint of alopecia were enrolled for the study "Analysis of Serum Zinc and Copper Concentrations in Hair Loss". The blood samples were analyzed for serum zinc and copper concentrations. The results revealed that, in hair loss patients, the serum zinc concentration was significantly lower than that of the control group, but the serum copper concentration was not significantly different.
Min Seong Kil et al. observed that "zinc-related metalloenzymes may have the potential to regulate hair growth. Zinc is a component of zinc finger motifs for many transcription factors, which regulate hair growth through hedgehog signaling, and is a catagen inhibitor via its inhibitory action on apoptosis-related endonucleases." They concluded that the mineral metabolism disturbances play a key role in hair loss, especially alopecia areata and telogen effluvium loss.
How zinc deficiency affects hairAmong the important functions of the mineral in the human body, the regulating of follicle cycling, inhibiting follicle regression and accelerating follicle recovery are noteworthy. Paus et al.20 reported that zinc has a potent dose-dependent immunomodulatory effect on the follicles. It is also a potent inhibitor of follicle regression and accelerates follicle recovery.
Even transient zinc deficiency is known to have an effect on the follicle function. The cellular processes like protein synthesis, cell division, cell repair, enzymatic reaction, utilization of vitamins are directly affected by the deficiency of zinc. Its deficiency weakens the structural integrity of the follicles. The deficiency the micronutrient leads to disturbances in the follicle cycling and anagen phase and also premature advancement of resting telogen phase. With retardation of anagen phase, the fresh supply of new hair strands is affected leading to more follicles in resting phase. The end effect is thinning of strands and apparent excessive loss.
Zinc deficiency can cause subclinical hypothyroidism which is known to cause hair loss. Ambooken Betsy et al. in their study 'Zinc Deficiency Associated with Hypothyroidism: An Overlooked Cause of Severe Alopecia' reported that "Hypothyroidism is a common and well recognized cause of diffuse hair loss". They added that "The hair loss attributed to hypothyroidism may not improve with thyroxine unless zinc supplements are added."
Correcting zinc deficiencyOysters, red meat, poultry, whole grains, dairy products, fortified cereals, beans, chickpeas and nuts are good sources. Supplements may be taken under the advice of the health care provider to correct the deficiency. Overdose of zinc can cause acute adverse effects and deficiency of other micronutrients. Patients with hereditary haemochromatosis may accumulate the mineral in their body. Very high doses of zinc are reported to inhibit both the anagen and catagen stages of hair growth.
1.Ambooken Betsy, MP Binitha, and S Sarita. Zinc Deficiency Associated with Hypothyroidism: An Overlooked Cause of Severe Alopecia. Int J Trichology. 2013 Jan-Mar; 5(1): 40–42.
2.The Office of Dietary Supplements, National Institutes of Health.
3.Min Seong Kil, Chul Woo Kim, Sang Seok Kim. Analysis of Serum Zinc and Copper Concentrations in Hair Loss. Ann Dermatol. 2013 Nov; 25(4): 405–409.
4.Karashima T, Tsuruta D, Hamada T, Ono F, Ishii N, Abe T, Ohyama B, Nakama T, Dainichi T, Hashimoto T. Oral zinc therapy for zinc deficiency-related telogen effluvium. Dermatol Ther. 2012 Mar-Apr;25(2):210-3.
5.Paus R, Christoph T, Müller-Röver S. Immunology of the hair follicle: a short journey into terra incognita. J Investig Dermatol Symp Proc. 1999 Dec;4(3):226-34