Jess says: As I’m sitting on the sofa, recovering from a horrible cold writing this, zinc seems the perfect mineral to tell you about. Today, my body is proof that despite a good diet, herbs and supplements, my immune system can’t overcome sleep deprivation, thanks to my son, Jack!
I find zinc excellent to help shorten and lessen the symptoms of a cold, and also to aid immune system problems. I will often consider how much zinc a patient has in any inflammatory disease or condition. I encourage my patients to make sure that they are eating zinc-rich foods regularly or to consider taking a supplement. I also recommend zinc in conditions such as male infertility, slow growth in children and immune system diseases.
Most people know that vitamin C can help to treat or reduce an infection, but do not know that zinc may be even more important in modern medicine. Are you getting enough of this essential nutrient in your diet?
zinc is an essential nutrient, so we need to ensure we have enough of it. Zinc is a nutrient that is essential for us to live. It’s critical for the healthy growth and development of children1 and is a key mineral for the functioning of our immune system.2 Zinc is important to the activity of over 300 enzymes and 1000 transcription factors in our body, and a lack of it can significantly impair brain function.3
Zinc deficiency affects up to 31% of humans globally.4 Deficiency is less common in developed countries, but can be found in people who eat a diet low in red meat and high in some breakfast cereals or beans (including soya), as these contain high levels of a chemical called phytate which interferes with our ability to absorb zinc.5
Zinc deficiency can be difficult to diagnose, as standard blood tests of zinc levels are not very accurate, and even a mild deficiency can cause an increased risk of infection.2
our immune system needs zinc to protect us from disease. Zinc is critical for our immune system, affecting some of our most important white blood cells (called T cells) – specifically TH1 and NK cells.6 Zinc also acts as an antioxidant and anti-inflammatory.3 Low zinc levels increase inflammatory chemicals in our bodies, which increase inflammation and our risk of a number of serious diseases.7
low zinc levels can cause brain and mood problems. Low zinc levels are more common in Alzheimer’s patients and patients suffering from depression.8 Young children with zinc deficiency have been found to have short-term memory problems, which improved significantly with zinc supplements.9
Zinc deficiency during pregnancy can cause long-term developmental, behavioural and brain problems for the child.10 Zinc deficiency can also induce anxious and depressive symptoms. Zinc supplements have been used as a treatment for major depression and have been shown to improve the effectiveness of medication.11
zinc deficiency can increase the risk of infections, asthma symptoms and allergic reactions. Taking a zinc supplement has been shown to reduce the risk of infection, particularly in the elderly.3 Zinc supplements have also been shown to help reduce the severity of colds and diarrhoea in pre-school children and were most effective when in the form of chelated zinc amino acids.12 Zinc supplements also improved pain and symptoms in urinary tract infections in children.13
Low zinc is more common in allergic patients14 and can lead to an increase in the number of asthma attacks in asthmatic children.15 Asthma symptoms are significantly improved by taking zinc supplements.16 Zinc in topical cream may also reduce allergic skin reactions like latex allergies.17
low zinc levels can affect hair growth and cause skin problems. Zinc is an important mineral for hair, and is commonly found to be low in patients with hair loss.18 Patients with alopecia areata (hair loss) often have low zinc levels, which also cause the disease to be more severe and last longer.19 Zinc deficiency can also lead to hypothyroidism, which can cause hair loss.
Zinc deficiency can cause a range of skin conditions, which are often misdiagnosed, as in the early stages they can resemble eczema and in the later stages produce a rash around the mouth, fingers, toes or anus.20 Eczema symptoms can be improved by taking zinc supplements in patients whose zinc levels are low.21
low zinc can stop wounds from healing, and cause macular degeneration. Chronic leg ulcers and wounds heal better with both zinc supplements and when using dressings containing zinc.22 Wounds are much slower to heal and have a higher rate of infection if the patients have low zinc levels.23 A daily zinc supplement can also slow the development of AMD (age-related macular degeneration); an eye disease that can cause blindness.24
zinc also plays an important role in male fertility. Zinc is necessary for the healthy function of the testicles and is essential for the production of sperm.25 It should therefore be considered in men with low sperm count or with fertility issues, and zinc-rich foods (see below) may be helpful in the months before conceiving a baby.
zinc is also important for gut health. Patients with Crohn’s disease show an improvement in their gut health (leaky gut symptoms stop) when taking zinc supplements.26 Zinc supplements also repair gut damage after methotrexate (a medication used in chemotherapy treatment).27 Zinc fortification can alter the gut microbiome, improving health28.
it may be helpful to take zinc supplements if you have a cold. A comprehensive medical review paper, the Cochrane report, recommends taking a zinc supplement at a high dose of 75mg within 24 hours of the onset of a cold, as it reduces the length of time of the cold and the severity of symptoms.29
do you drink too much alcohol, or suffer from acute macular degeneration or diarrhoea? Zinc has been very successfully used to prevent blindness in patients suffering from dry Acute Macular Degeneration3 and to help diarrhoea, particularly in children.3 Zinc deficiency is also more commonly seen in patients with bowel disease, kidney disease, liver disease, high alcohol intake and other serious long-term illnesses.30
zinc may also benefit
- Patients with burning mouth syndrome with low zinc levels had a significant improvement in symptoms, after taking a zinc supplement for six months.31
- Animal studies showed that a slight zinc deficiency affected prostate health and increased damage, especially during physical exercise.32
- Zinc deficiency may increase and cause ageing of our cells, due to its role in DNA.33
- Babies born before term given zinc supplements showed better signs of brain development with alertness and attention and a lower incidence of brain problems.34 Zinc supplementation reduces death and illness in pre-term babies.35
- Taste problems – Zinc deficiency is shown to reduce our sense of taste.36
- Night blindness – Zinc deficiency is shown to reduce our ability to see at night.36
- Crohn’s disease – Zinc deficiency is more common in patients with Crohn’s disease and a deficiency may increase the risk of developing fistulas.37
- Growth in children – Zinc supplementation improved growth in short male children.38
- Zinc supplementation from an early age significantly reduces complications from sickle cell anaemia.39
- Chemotherapy side effects: A study showed children with leukaemia lowered their risk of infection and the side effects of chemotherapy when taking zinc supplements.40 Low zinc levels with head and neck cancer resulted in larger and more aggressive tumours, and more complications.41
- Zinc deficiency is more common in patients with Down’s syndrome. This increases the risk of infection, which can be corrected by supplements.42
- Hypothyroidism: Zinc supplements can improve T3 levels, decrease TSH levels and improve conversion from T4 (the inactive form of thyroid hormone) to T3 (it’s active form).43
contraindications of taking zinc supplements
Zinc supplementation at a reasonable dose is generally safe, however, at high doses, it can cause copper deficiency, which can have severe side effects.44 Be cautious of zinc supplementation if you suspect that you may have, or have been diagnosed with, low copper levels. High zinc can also suppress iron levels.
the top five sources of zinc
Zinc needs to be taken daily, as the body has no ability to store it. Vegetarians, vegans and those with digestive problems are more likely to be low in zinc. The recommended daily amount of zinc we should have is between 7-11mg daily. Up to 25mg daily is considered to be safe. Natural sources of zinc include:
- Oysters (90.5mg, per 100g)
- Pumpkin seeds (7.6mg, per 100g)
- Crab (7.6mg, per 100g)
- Cashew nuts – raw (5.8mg, per 100g)
- Beef – mince, cooked (4.8mg, per 100g)
- Chickpeas – tinned (1.5mg, per 100g)
natural sources to add zinc to your diet
eat pumpkin seeds: One of the best food sources of zinc, pumpkin seeds are delicious roasted. They can be sprinkled on salads or porridge or over cooked vegetables. Half a cup provides 8.4mg.
eat high-quality grass-fed beef or lamb: Grass-fed organic beef or lamb is shown to be higher in zinc (approximately 6mg per 100g), than non-organic, intensively farmed meat.
swap peanut butter for cashew nut butter: Instead of peanut butter, which can be inflammatory for some people, swap to healthier, delicious and higher-in-zinc cashew nut butter. Half a cup of cashews contains 3.8mg of zinc. Cashew nut butter also makes a great addition to smoothies and a spoonful stops hunger pangs!
consume kefir daily: A daily cup of kefir, which can be made into a healthy smoothie contains 1.4mg of zinc, as a bonus to its’ many other health benefits!
take a supplement: If you are concerned that you are zinc deficient (seek advice if necessary from a functional medical practitioner), or to help prevent colds or infection you could take a supplement. Stick to under 25mg daily and make sure you are taking a multivitamin containing copper as well (to prevent copper deficiency). Zinc gluconate is a chelated form of zinc that is easily absorbed and suitable for both adults and children.
- Kambe T, Fukue K, Ishida R, Miyazaki S.Overview of Inherited Zinc Deficiency in Infants and Children J Nutr Sci Vitaminol (Tokyo). 2015;61 Suppl:S44-6. doi: 10.3177/jnsv.61.S44. PMID: 26598882.
- Livingstone C. Zinc: physiology, deficiency, and parenteral nutrition Nutr Clin Pract. 2015 Jun;30(3):371-82. doi: 10.1177/0884533615570376. Epub 2015 Feb 13. PMID: 25681484.
- Prasad AS. Discovery of human zinc deficiency: its impact on human health and disease Adv Nutr. 2013 Mar 1;4(2):176-90. doi: 10.3945/an.112.003210. PMID: 23493534; PMCID: PMC3649098.
- Chapter 5 ZiNC DEFiCiENCY
- Sandstead HH, Freeland-Graves JH.Dietary phytate, zinc and hidden zinc deficiency J Trace Elem Med Biol. 2014 Oct;28(4):414-7. doi: 10.1016/j.jtemb.2014.08.011. Epub 2014 Aug 29. PMID: 25439135
- Prasad AS. Zinc and immunity Mol Cell Biochem. 1998 Nov;188(1-2):63-9. PMID: 9823012.
- Wessels I, Haase H, Engelhardt G, Rink L, Uciechowski P..Zinc deficiency induces production of the proinflammatory cytokines IL-1β and TNFα in promyeloid cells via epigenetic and redox-dependent mechanisms J Nutr Biochem. 2013 Jan;24(1):289-97. doi: 10.1016/j.jnutbio.2012.06.007. Epub 2012 Aug 16. PMID: 22902331
- Jurowski K, Szewczyk B, Nowak G, Piekoszewski W. Biological consequences of zinc deficiency in the pathomechanisms of selected diseases J Biol Inorg Chem. 2014 Oct;19(7):1069-79. doi: 10.1007/s00775-014-1139-0. Epub 2014 Apr 19. Erratum in: J Biol Inorg Chem. 2015 Oct;20(7):1219. PMID: 24748223; PMCID: PMC4175048.
- Umamaheswari K, Bhaskaran M, Krishnamurthy G, Vasudevan H, Vasudevan K. Effect of iron and zinc deficiency on short term memory in children Indian Pediatr. 2011 Apr;48(4):289-93. doi: 10.1007/s13312-011-0060-7. Epub 2010 Aug 1. PMID: 20972302.
- Adamo AM, Oteiza PI. Zinc deficiency and neurodevelopment: the case of neurons Biofactors. 2010 Mar-Apr;36(2):117-24. doi: 10.1002/biof.91. PMID: 20333753; PMCID: PMC3506421.
- Cope EC, Levenson CW. Role of zinc in the development and treatment of mood disorders Curr Opin Clin Nutr Metab Care. 2010 Nov;13(6):685-9. doi: 10.1097/MCO.0b013e32833df61a. PMID: 20689416.
- Sánchez J, Villada OA, Rojas ML, Montoya L, Díaz A, Vargas C, Chica J, Herrera AA. [Effect of zinc amino acid chelate and zinc sulfate in the incidence of respiratory infection and diarrhea among preschool children in child daycare centers] Biomedica. 2014 Jan-Mar;34(1):79-91. Spanish. doi: 10.1590/S0120-41572014000100011. PMID: 24967861.
- Cope EC, Levenson CW..Zinc Supplementation in Treatment of Children With Urinary Tract Infection Curr Opin Clin Nutr Metab Care. 2010 Nov;13(6):685-9. doi: 10.1097/MCO.0b013e32833df61a. PMID: 20689416
- Di Toro R, Galdo Capotorti G, Gialanella G, Miraglia del Giudice M, Moro R, Perrone L. Zinc and copper status of allergic children Acta Paediatr Scand. 1987 Jul;76(4):612-7. doi: 10.1111/j.1651-2227.1987.tb10530.x. PMID: 3630679.
- Khanbabaee G, Omidian A, Imanzadeh F, Adibeshgh F, Ashayeripanah M, Rezaei N. Serum level of zinc in asthmatic patients: a case-control study Allergol Immunopathol (Madr). 2014 Jan-Feb;42(1):19-21. doi: 10.1016/j.aller.2012.07.008. Epub 2013 Jan 9. PMID: 23312452.
- Ghaffari J, Khalilian A, Salehifar E, Khorasani E, Rezaii MS. Effect of zinc supplementation in children with asthma: a randomized, placebo-controlled trial in northern Islamic Republic of Iran East Mediterr Health J. 2014 Jun 18;20(6):391-6. PMID: 24960516.
- Modak S, Gaonkar TA, Shintre M, Sampath L, Caraos L, Geraldo I. A topical cream containing a zinc gel (allergy guard) as a prophylactic against latex glove-related contact dermatitis Dermatitis. 2005 Mar;16(1):22-7. PMID: 15996346.
- Kil MS, Kim CW, Kim SS. Analysis of serum zinc and copper concentrations in hair loss Ann Dermatol. 2013 Nov;25(4):405-9. doi: 10.5021/ad.2013.25.4.405. Epub 2013 Nov 30. PMID: 24371385; PMCID: PMC3870206.
- Abdel Fattah NS, Atef MM, Al-Qaradaghi SM..Evaluation of serum zinc level in patients with newly diagnosed and resistant alopecia areata Int J Dermatol. 2016 Jan;55(1):24-9. doi: 10.1111/ijd.12769. Epub 2015 Jul 3. PMID: 26147750
- Kumar P, Lal NR, Mondal AK, Mondal A, Gharami RC, Maiti A. Zinc and skin: a brief summary Zinc and skin: a brief summary. Dermatol Online J. 2012 Mar 15;18(3):1. PMID: 22483512
- Kim JE, Yoo SR, Jeong MG, Ko JY, Ro YS. Hair zinc levels and the efficacy of oral zinc supplementation in patients with atopic dermatitis Acta Derm Venereol. 2014 Sep;94(5):558-62. doi: 10.2340/00015555-1772. PMID: 24473704.
- Lansdown AB, Mirastschijski U, Stubbs N, Scanlon E, Agren MS. Zinc in wound healing: theoretical, experimental, and clinical aspects Wound Repair Regen. 2007 Jan-Feb;15(1):2-16. doi: 10.1111/j.1524-475X.2006.00179.x. PMID: 17244314
- Kogan S, Sood A, Garnick MS. Zinc and Wound Healing: A Review of Zinc Physiology and Clinical Applications Wounds. 2017 Apr;29(4):102-106. PMID: 28448263.
- Smailhodzic D, van Asten F, Blom AM, Mohlin FC, den Hollander AI, van de Ven JP, van Huet RA, Groenewoud JM, Tian Y, Berendschot TT, Lechanteur YT, Fauser S, de Bruijn C, Daha MR, van der Wilt GJ, Hoyng CB, Klevering BJ. Zinc supplementation inhibits complement activation in age-related macular degeneration PLoS One. 2014 Nov 13;9(11):e112682. doi: 10.1371/journal.pone.0112682. PMID: 25393287; PMCID: PMC4231060.
- Prasad AS.Clinical and biochemical manifestations of zinc deficiency in human subjects J Am Coll Nutr. 1985;4(1):65-72. Doi: 10.1080/07315724. 1985.10720067. PMID: 2580877
- El-Tawil AM. Zinc supplementation tightens leaky gut in Crohn’s disease Inflamm Bowel Dis. 2012 Feb;18(2):E399. doi: 10.1002/ibd.21926. Epub 2011 Oct 12. PMID: 21994075.
- Musa NS, Howarth GS, Tran CD. Zinc Supplementation Alone Is Effective for Partial Amelioration of Methotrexate-induced Intestinal Damage. Altern Ther Health Med. 2015;21 Suppl 2:22-31. PMID: 26308757.Zinc Supplementation Alone Is Effective for Partial Amelioration of Methotrexate-induced Intestinal Damage Altern Ther Health Med. 2015;21 Suppl 2:22-31. PMID: 26308757.
- Reed S, Knez M, Uzan A, Stangoulis JCR, Glahn RP, Koren O, Tako E..Alterations in the Gut ( Gallus gallus) Microbiota Following the Consumption of Zinc Biofortified Wheat ( Triticum aestivum)-Based Diet J Agric Food Chem. 2018 Jun 27;66(25):6291-6299. doi: 10.1021/acs.jafc.8b01481. Epub 2018 Jun 15. PMID: 29871482
- Singh M, Das RR .Zinc for the common cold Cochrane Database Syst Rev. 2013 Jun 18;(6):CD001364. doi: 10.1002/14651858.CD001364.pub4. Update in: Cochrane Database Syst Rev. 2015;(4):CD001364. PMID: 23775705
- Prasad AS. Discovery of human zinc deficiency: its impact on human health and disease Adv Nutr. 2013 Mar 1;4(2):176-90. doi: 10.3945/an.112.003210. PMID: 23493534; PMCID: PMC3649098
- Cho GS, Han MW, Lee B, Roh JL, Choi SH, Cho KJ, Nam SY, Kim SY. .Zinc deficiency may be a cause of burning mouth syndrome as zinc replacement therapy has therapeutic effects J Oral Pathol Med. 2010 Oct;39(9):722-7. doi: 10.1111/j.1600-0714.2010.00914.x. Epub 2010 Jul 2. PMID: 20618611
- Song Y, Elias V, Loban A, Scrimgeour AG, Ho E. Marginal zinc deficiency increases oxidative DNA damage in the prostate after chronic exercise Free Radic Biol Med. 2010 Jan 1;48(1):82-8. doi: 10.1016/j.freeradbiomed.2009.10.030. Epub 2009 Oct 28. PMID: 19836448; PMCID: PMC4090116
- Garfinkel D. Is ageing inevitable? The intracellular zinc deficiency hypothesis of ageing 1986 Feb;19(2):117-37. doi: 10.1016/0306-9877(86)90053-8. PMID: 3517602
- Mathur NB, Agarwal DK. Zinc Supplementation in Preterm Neonates and Neurological Development, A Randomized Controlled Trial Indian Pediatr. 2015 Nov;52(11):951-5. doi: 10.1007/s13312-015-0751-6. PMID: 26615342.
- Terrin G, Berni Canani R, Passariello A, Messina F, Conti MG, Caoci S, Smaldore A, Bertino E, De Curtis M. Zinc supplementation reduces morbidity and mortality in very-low-birth-weight preterm neonates: a hospital-based randomized, placebo-controlled trial in an industrialized country Am J Clin Nutr. 2013 Dec;98(6):1468-74. doi: 10.3945/ajcn.112.054478. Epub 2013 Sep 11. PMID: 24025633.
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- Kruis W, Rindfleisch GE, Weinzierl M. Zinc deficiency as a problem in patients with Crohn’s disease and fistula formation Hepatogastroenterology. 1985 Jun;32(3):133-4. PMID: 4018707.
- Kaji M, Gotoh M, Takagi Y, Masuda H, Kimura Y, Uenoyama Y. Studies to determine the usefulness of the zinc clearance test to diagnose marginal zinc deficiency and the effects of oral zinc supplementation for short children J Am Coll Nutr. 1998 Aug;17(4):388-91. doi: 10.1080/07315724.1998.10718781. PMID: 9710851.
- Prasad AS. Zinc deficiency and effects of zinc supplementation on sickle cell anemia subjects Prog Clin Biol Res. 1981;55:99-122. PMID: 7291206.
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- Mahmoodianfard S, Vafa M, Golgiri F, Khoshniat M, Gohari M, Solati Z, Djalali M. Effects of Zinc and Selenium Supplementation on Thyroid Function in Overweight and Obese Hypothyroid Female Patients: A Randomized Double-Blind Controlled Trial J Am Coll Nutr. 2015;34(5):391-9. doi: 10.1080/07315724.2014.926161. Epub 2015 Mar 11. PMID: 25758370.
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