Zinc is a micronutrient that plays an important role in various bodily functions such as reproduction, immune function, and wound repair. It is also necessary for the growth and development of fetus during pregnancy, childhood, and adolescence.
Zinc deficiency refers to the low levels of zinc (less than 0.66 to 1.10 mcg/ml) in the body. The deficiency of zinc can be congenital (present from birth) or acquired.
Zinc can not be synthesized by our body, so it has to be taken from outside sources. The recommended dietary allownace (RDA) of zinc varies from 3 mg/day in children to 8 mg/day and 11 mg/day in women and men respectively. However, it is higher in pregnant and lactating women.
Its deficiency can be easily reversed by consuming foods rich in zinc such as oysters, red meat, poultry, dairy products, legumes, beans, cashews, chia seeds, and pumpkin seeds. In case of severe deficiency, supplements may be prescribed by your doctor.
The symptoms of zinc deficiency start appearing after months of having low levels of zinc. The symptoms vary as per the levels of zinc and are non-specific, often resembling other medical conditions. Therefore, it is necessary to conduct a medical examination for confirmation.
People with zinc deficiency may experience:
Skin rash
Skin ulcers
Diarrhea
Frequent cold and infections
Weight loss
Delayed wound healing
Decrease in the sense of smell or taste
Loss of appetite
Eye and skin lesions
Vision problems
Mental lethargy
Hypogonadism (in males)
Impotence
In children and adolescents there can be:
Growth retardation
Delayed puberty
Difficulty in learning
Zinc deficiency is mostly seen in developing and underdeveloped countries due to malnutrition. However, cases are also seen in developed countries as a result of various chronic illnesses. Zinc deficiency can be acquired or congenital.
The main causes of acquired zinc deficiency can be:
Decreased intake of zinc
Decreased absorption of zinc
Increased demand of zinc
Excessive loss of zinc
1. Decreased intake of zinc
Inadequate intake of zinc is mostly related to:
A person may also have zinc deficiency even if he/she is taking adequate amounts of zinc. This can be due to the excessive consumption of certain food items or medications which can hinder the absorptions of zinc, and presence of certain disorders. These include:
3. Increased demand of zinc
The demand of zinc increases during pregnancy and lactation as it is required in the growth and development of the baby. The demands of the body increases as below:
Pregnant women (18 years of age and younger): 12 mg per day
Pregnant women (19 years of age and older): 11 mg per day
Breastfeeding women (18 years of age and younger): 13 mg per day
Breastfeeding women (19 years of age and older): 12 mg per day
Zinc, if not taken in adequate amounts during pregnancy and breastfeeding, can cause certain fetal defects and low birth weight.
Are you eating the right type of food during pregnancy? Read in detail about various foods that should be eaten and avoided for a healthy pregnancy.
4. Increased loss of zinc
In some cases, there can be excessive loss of zinc from the body which can also be a cause of zinc deficiency. This includes:
Dialysis
Hemodialysis
Hemolysis
Diarrhea
Urinary loss (due to diuretics or alcohol use)
Although zinc deficiency is commonly caused by dietary factors, several inherited conditions have also been found. Acrodermatitis enteropathica is one of the common inherited condition seen in humans.
Acrodermatitis enteropathica: It is a rare form of zinc deficiency.which causes impaired absorption of zinc. It occurs in both congenital and acquired forms. The congenital form results from intestinal disorders due to genetic abnormality, whereas the acquired forms can result due to:
Lack of secretion of zinc in the breast milk
After surgery of intestine
Adopting special intravenous nutritional programs
There is a decrease in the absorption of zinc in people suffering from gastrointestinal disease such as ulcerative colitis, Crohn’s disease, and short bowel syndrome. People with these diseases or those who have undergone gastrointestinal surgery are more prone to zinc deficiency.
Some diseases may decrease the zinc absorption and increase the loss of zinc, making the patient vulnerable to zinc deficiency. These include sickle cell anemia, chronic kidney disease, liver disease, chronic diarrhea, HIV infection, diabetes, malabsorption syndrome and cancer.
The absorption of zinc from vegetarian diets is less than non-vegetarian diets. Also, the food consumed by vegetarians mostly contains phytates that inhibit the absorption of zinc. Due to this, vegetarians are at a higher risk of developing zinc deficiency.
Zinc is required for fetal growth and development. Pregnant and breastfeeding women are at high risk of zinc deficiency due to high fetal demand during this phase.
About 30-50% of people who consume alcohol suffer from zinc deficiency as alcohol decreases the absorption of zinc and increases its excretion in urine.
Zinc is a micronutrient that cannot be synthesized by the body. It has to be taken from outside sources. People living in developing or underdeveloped countries have a limited access to thsese food which increase the risk of zinc deficiency.
An adequate amount of fiber in the diet is very essential for a healthy digestive system. But, excessive consumption of fiber can also hamper the absorption of essential nutrients such as zinc.
The elderly people especially above 75 years of age are at a higher risk of having zinc deficiency. This is because of slow metabolism, poor appetite, and less diversification in the diet.
Prolonged stress is also found to reduce the levels of zinc in the body.
Breast milk provides 2 mg/day of zinc which is sufficient only for initial 4-6 months. The dietary requirement for zinc for the older infants aged 7-12 months increases. At this age, if the infant is only having breast milk they can suffer from zinc deficiency.
Zinc level: This test checks the amount of zinc in the blood which does not necessarily reflect its level within the cells. Zinc deficient people can have normal zinc levels in the blood. The level also varies as per circadian rhythm, drugs and meals taken. It is usually high in the morning and low in the evening. The normal range is 0.60-1.20 mcg/mL for children and 0.66-1.10 mcg/mL for adults.
In the presence of zinc deficiency, the absorption of copper is increased. Alongwith the serum level of zinc, levels of copper and serum copper/zinc ratio is also measured. Serum copper level over 120g/dl and a serum copper/zinc ratio of 1.5 also indicate zinc deficiency.
Additionally, several blood tests are also done to rule out other conditions or vitamin deficiencies. These include:
Complete blood count (CBC)
Serum electrolytes
Oral zinc tolerance test: In this test, the levels of zinc are measured after administering zinc. This test helps to detect zinc deficiency caused due to decreased absorption of zinc in the body.
Zinc dependent enzymes: The activities of various zinc-dependent enzymes are also measured to assess zinc deficiency. Alkaline phosphatase, carboxypeptidase, and thymidine kinase are three such enzymes. A quantitative measurement of these enzymes also gives an idea of zinc deficiency.
The excretion of zinc in urine is decreased as a result of zinc deficiency. The determination of zinc in a 24-hr urine sample also helps in diagnosing zinc deficiency. However, this is not a reliable method for determining acute cases of zinc deficiency.
Zinc level is also measured in hair. Chronic zinc deficiency is reflected more accurately in hair than in blood.
Although zinc deficiency is not an emergency condition, you may consult the doctor in case you:
If you are pregnant or breastfeeding, and suspect deficiency of zinc, consult your doctor immediately as zinc plays an important role in the growth and development of the fetus and newborn baby.
Specialists you may consult are:
General physician
Internal medicine specialist
Gynecologist (in case of pregnancy and breastfeeding women)
If you are noticing any symptoms of zinc deficiency, seek advice from our world-class medical professionals.
Zinc deficiency can be easily prevented by taking the recommended amount of zinc either through dietary sources or supplements.
Oysters contain the maximum amount of zinc per serving compared to any other food.
Beef, red meat, poultry, and certain types of seafood (such as crab and lobster) also have a good amount of zinc.
Many grains, plants and dairy based foods are also good sources of zinc. These include oats, legumes, chickpeas, beans, cashews, almonds, peas, chia seeds, and pumpkin seeds.
Patients suffering from zinc deficiency can manage it by increasing the intake of zinc through diet. If dietary modifications fail to show any improvement in your condition, your doctor might recommend supplementation.
The treatment of zinc deficiency usually begins with oral supplementation which has proven to reduce the symptoms. The recommended daily intake of zinc is:
3 mg/day for children less than 4 years
5 mg/day for children between 4 to 8 years
8 mg/day for children between 9 to13 years
9 mg/day for women (non-pregnant and non-lactating)
Higher doses of zinc (more than 50 mg/kg) is required in patients who have severe deficiency. It is mostly needed in patients having chronic illnesses such as Crohn's disease and short bowel syndrome. High levels of zinc can interfere with copper and iron metabolism, so it is important to monitor the levels of zinc regularly in the patients taking zinc supplements. Supplements are taken for a lifetime in a condition called acrodermatitis enteropathica.
Zinc supplements are available in the form of:
Zinc sulfate
Zinc acetate
Zinc aspartate
Zinc orotate
Zinc gluconate
Parenteral zinc supplementation is recommended in rare cases such as intestinal failure or if the patient is on total parenteral nutrition (TPN).
1. Age-related macular degeneration (AMD): AMD is an eye disorder that causes vision loss. Studies suggest that zinc supplements help in the slow progression of AMD.
2. Growth failure: Since zinc is required for normal growth and development of the child, a low level of zinc for a long period of time can hamper its overall growth and development.
3. Skin problems: Skin complications associated with zinc deficiency include acrodermatitis enteropathica, cheilitis, and dermatitis.
4. Diabetes mellitus and obesity: A prolonged and severe zinc deficiency is also associated with an increased risk of diabetes and obesity. The exact mechanism behind this correlation is not known.
5. Attention deficit hyperactivity disorder (ADHD): Zinc deficiency in children can cause ADHD in children. ADHD is accompanied by lack of activity and impaired socialization in children.
Read more about other causes, symptoms and management of ADHD.
Other complications associated with zinc deficiency are:
Delayed wound healing
Low bone mineral density
Hypogonadism
Diarrhea
Zinc has antioxidant properties which protect from free radicals. Low levels of zinc also increases the risk of cancers and heart disease.
Note: Maternal zinc deficiency during pregnancy can cause abortion, preterm bith, still birth and fetal neural tube defects. Babies born to such mothers have low birth weight.
Zinc also possesses antiviral and antiinflammatory properties. Deficiency of zinc may reduce the immunity (the ability of the body to fight infections). People with low levels of zinc are more prone to coronavirus infection. Zinc supplementation is hence used as an adjuvant therapy in faster recovery, treatment and prevention of COVID-19 because of its following potential benefits. Zinc helps by:
Restricting the entry of virus in the body
Inhibiting multiplication of the virus
Modulating immune response
To know more about COVID-19, its treatment & latest updates/news, check out our coronavirus section.
1. Holy basil (Tulsi): It is considered as the “Queen of herbs” in Ayurveda. It contains zinc along with Vitamin A and C, calcium, and iron.
2. Indian pennywort (Brahmi): It is an Ayurvedic herb that is rich in zinc. It is known to exhibit antioxidant properties which helps in increasing memory, concentration, and brain power.
3. Asparagus racemosus (Shatavari): It is known for its fertility properties but it is also a very good source of zinc. It contains 0.54 mg zinc per 100 gm serving. It boosts immunity and also helps to fight stress, anxiety, and depression.
4. False daisy (Bhringraj): It is known for its moisturizing and nourishing properties. It is also a source of zinc along with other micronutrients such as copper, sodium, iron, and potassium.
Several homeopathic medications such as Zincum aceticum and Zincum metallicum are also available for zinc deficiency.
Zinc deficiency can be easily reversed through proper supplementation and diet. You can keep the following points in mind while managing zinc deficiency.
Changing the way of cooking certain foods can increase the absorption of zinc. For example soaking beans before cooking or leavening foods can lower the phytates concentration, making it easier for the body to process zinc.
A person having zinc deficiency can have other nutritional deficiencies. Consult your doctor as soon as you notice any other symptoms of nutritional deficiencies.
Overdose of zinc supplements can also cause toxicity and lead to symptoms such as nausea and vomiting. To avoid this, zinc supplements should always be taken as per your doctor's recommendation. The dose of zinc varies as per your age and other conditions such as pregnancy and breastfeeding. The patients who are on zinc supplements should get their zinc level tested every three months.
Before taking any zinc supplement, talk to your doctors as the dose varies as per your medical condition. The dose also varies, if you are on some other medications.
The foods that are high in calcium and phosphorus such as milk, cheese, yogurt, dried beans, lentils, and nuts delay the absorption of zinc. So, avoid taking zinc supplements with such food items.
Some patients taking zinc supplements can have allergy reactions which can be experienced as:
Hives
Difficulty in breathing
Swelling of face, lips, tongue, and throat
Upset stomach
Consult your doctor immediately, if you have any of these symptoms.
Certain medications such as antibiotics, penicillamine, and chlorthalidone can reduce the absorption of zinc in the body. It is very important to discuss all the dietary supplements and medications you are already taking before initiating zinc therapy.
