Zinc is an essential mineral found in every tissue of the body. It is present in every known class of enzyme and, therefore, a player in all biochemical pathways the body undertakes. With its pervasive role, no wonder zinc has so many benefits for human health.
While only needed in trace amounts, zinc deficiency, even mild kinds, can play havoc with your health. In order to obtain the many benefits of zinc, it is important to get enough, whether through diet or zinc supplements and avoid the potential health problems of too little.
Zinc is essential for growth, protein production, cell division, DNA synthesis, immune function, wound healing, bone and teeth formation, skin renewal, brain activity, proper nervous system function, and production and action of hormones including male and female sex hormones, insulin and stress hormones.
Zinc Helps Immune Function
Research shows that even mild zinc deficiency impairs white blood cell function and lowers immunity to pneumonia and other infections. Zinc supplements can eliminate the problem.
Who is not getting enough Zinc or the Benefits of Zinc?
While zinc deficiency is not widespread in North America, there are certain sub-groups at risk for not getting enough, especially older adults, people on restricted diets and those who drink excessive alcohol.
35%–45% of adults age 60 and over are believed to not get enough zinc. 30–50% of alcoholics are deficient.
In addition there are those who, while they may get adequate amounts of zinc according to government guidelines, show clinical symptoms of zinc deficiency because of the other substances they ingest, like alcohol, medications or an excess of other minerals like copper, that may work to diminish the effectiveness or absorption of the zinc. The result is these people don’t get the benefits of zinc.
Symptoms of Zinc Deficiency
The following symptoms of Zinc deficiency may indicate an individual is not getting enough and missing out on the benefits of zinc.
- Soft nails including white lines
- Stretch marks
- Pale skin
- Growth retardation
- Loss of appetite
- Impaired immune function including susceptibility to infection
- Dry Hair
- Delayed sexual development
- Low testosterone and impotence
- Eye and skin lesions
- Night blindness
- Weight loss
- Altered taste
- Morning sickness during pregnancy
- Mental lethargy and emotional disturbances including anxiety
Zinc Deficiency Diseases/Conditions — When you’re not getting the benefits of zinc
The list of conditions related to zinc deficiency is extensive.
- Hypogonadism (resulting in reduced testosterone)
- Alopecia (hair loss)
- Age related macular degeneration
- Birth defects
Because zinc’s functions in the body are widespread, the symptoms and conditions of zinc deficiency can be diverse.
The Benefits of Zinc are not limited to Zinc related Conditions — Other Nutrients Rely on Zinc
Zinc is a player in the metabolism and function of other nutrients.
- Vitamin A functions better with sufficient zinc to prevent mouth ulcers, poor night vision, dry flaky skin and frequent colds.
- Vitamin B 6 (Pyrodoxine), along with zinc, helps reduce the symptoms of PMS and depression when in the presence of adequate zinc.
- Omega 3 and Omega 6 are converted, with the help of zinc, into beneficial forms that ensure these fatty acids’ anti-inflammatory and anti-depressant effects.
Benefits of Zinc — Clobbering the Common Cold with Zinc
Zinc is anti-viral. Research shows that zinc lozenges and syrup shorten the duration and possibly the severity of symptoms of the common cold when taken within 24 hours of the start of symptoms. Zinc nose sprays and gels should be avoided for risk of permanent loss of smell.
Reasons for insufficient Zinc – and why you may not be getting all the possible benefits of zinc
Three reasons why you may not get enough zinc and, therefore, miss important benefits of zinc are as follows:
- Insufficient intake of zinc via diet or poor absorption because of intestinal problems, chronic disease or the presence of other substances or drugs that prevent absorption.
- Accelerated loss of zinc through stress, alcohol, medication or other means.
- Increased need, for example, because of pregnancy, breastfeeding, exercise or illness.
Risk Factors for Zinc Deficiency That May Prevent you Enjoying the Benefits of Zinc
The following are some risk factors for zinc deficiency.
- Inadequate calorie intake - Zinc deficiency is widespread in parts of the world where famine and inadequate nutrition are endemic. Anorexics generally have chronically low zinc levels – a chicken and egg situation because one sign of low zinc stores is loss of appetite.
- Over-reliance on Refined and Processed Foods – Refining of whole grains routinely removes most zinc. It follows that highly processed diets are often zinc deficient.
- Alcohol – Alcohol is a double whammy when it comes to zinc. Ethanol decreases zinc absorption and increases urinary zinc excretion. This may explain why 30%-50% of alcoholics are estimated to be zinc deficient.
- Malabsorption conditions – A host of medical conditions can lead to zinc deficiency including: Ulcerative colitis and Chron’s disease, Malabsorption syndrome, Liver disease, Kidney disease, Diabetes – Zinc is needed to make, secrete and store insulin, Cancer,Chronic diarrhea, Sickle cell disease
- Vegetarian or Vegan Diet – Some of the most bio-available dietary sources of zinc are animal products, especially oysters and red meat. Plant based sources of zinc are sometimes poorly absorbed because of the presence of phytates that diminish zinc absorption. Because of these absorption issues, vegetarians may need to consume more zinc than meat eaters, either through diet or zinc supplements.
- Pregnancy and lactation – Both conditions increase substantially a woman’s need for zinc.
- Older infants who are exclusively breastfed, unless the mother consumes adequate zinc
How Much Zinc Do you Need to Achieve the Benefits of Zinc?
The U.S. government’s Recommended Dietary Intake (RDA) for adults age 19+ per day is
- 11 mg for men
- 9 mg for women
- 11 mg for pregnant women
- 12 mg for lactating women
To see RDAs for other ages as well as more on zinc, click on NIH’s Zinc Fact Sheet outlining the benefits of zinc.
Note that the above figures are based on the typical American diet that includes significant amounts of red meat and poultry – two zinc rich sources. If you are vegetarian or avoid animal protein including seafood, you many need additional zinc, due to the phytates contained in some plant foods containing zinc that diminish zinc absorption.
Also remember that RDA’s are not designed for optimum health but instead to avoid deficiency diseases. Many experts, including Patrick Holford, author of The New Optimum Nutrition Bible believe that a more optimal intake for zinc is 20 mg per day for a non-pregnant and non- breastfeeding adult in order to achieve the benefits of zinc.
Consuming zinc rich foods or, failing that taking zinc supplements for any shortfall on a regular basis, is important, because the storage capacity for zinc in the body is limited.
How to Best Absorb Zinc – Zinc Cofactors/Helpers – Strategies for Maximizing Benefits of Zinc
To adequately metabolize zinc, it’s important to have adequate (but not excessive) amounts of the following:
- stomach acid (hydrochloric acid)
- Vitamins A, E, D & B6
- Magnesium, Calcium and Phosphorus.
Interestingly, older people often are deficient in stomach acid, which may help explain the high number of elderly who are zinc deficient.
Zinc Thieves – The Factors that Reduce the Benefits of Zinc
There are several nutrients and substances that can prevent effective zinc absorption or metabolism and, therefore, reduce the benefits of zinc.
Phytates in whole grains and legumes and oxalates in rhubarb and spinach bind with zinc to prevent the latter’s absorption. This is why vegans who avoid animal protein should ensure adequate zinc intake and take measures to remove phytates from legumes and whole grains by soaking beans before cooking and baking grains.
Diuretics increase zinc excretion by as much as 60%.
Zinc interacts with the antibiotics quinolone (Cipro) and tetracycline to inhibit the absorption of both the zinc and the drugs. To avoid reducing the effectiveness of either, take antibiotics at least 2 hours before or 4 -6 hours after zinc supplements.
Alcohol both prevents zinc absorption and increases zinc excretion.
Refined sugar requires zinc to metabolize, in turn, reducing zinc stores.
Calcium and iron supplementation in excess can reduce zinc stores by acting as antagonists to zinc.
Similarly, excess copper can deplete zinc stores. This may occur more frequently than thought, because of the ubiquitous presence of copper in multi-vitamins, birth control pills, copper IUDs, in water flowing through copper pipes, copper cook ware etc.
For more on copper’s role in diminishing zinc, see Ann Louise Gittleman’s book Why am I always so tired? Discover How Correcting your Body’s Copper Imbalance Can Keep your Body from Giving out before your Mind Does.
Low protein intake prevents efficient zinc metabolism.
Insufficient Vitamin D can make zinc less effective.
Zinc–Rich Foods and Sources – Achieving the benefits of Zinc through zinc rich food The best food source of zinc is oysters. Indeed the oyster’s reputation as an aphrodisiac stems from it being zinc rich. Zinc is a necessary component of the male sex hormone testosterone essential for virility and responsible, when insufficient, for impotence and infertility. No wonder oysters have the reputation they do. 100 grams or 3.5 ounces of raw oysters contain approximately 90 mg of zinc! Other seafood like lobster and crab are also good sources of zinc. Fish like haddock and sole are sources too. Red meat including lamb and beef contain significant zinc. Poultry including turkey and chicken are also sources.
Nuts and Seeds including pecans, almonds, brazil nuts, peanuts and pumpkin seeds are good sources.
Whole grains including whole wheat, rye, oats as well as legumes like chickpeas and most beans are good sources of zinc, especially when prepared to remove phytates.
Strategies for Achieving Zinc Benefits – Eat Enough Zinc Rich Foods
Zinc in Food – Benefits of Zinc
Zinc Content of Food in mg
- Oysters, cooked, breaded and fried, 3 ounces – 74 mg
- Beef chuck roast, braised, 3 ounces– 7 mg
- Crab, Alaska king, cooked, 3 ounces – 6.5 mg
- Beef patty, broiled, 3 ounces- 5.3 mg
- Breakfast cereal, fortified with 25% of the DV for zinc, ¾ cup - 3.8 mg
- Lobster, cooked, 3 ounces – 3.4 mg
- Pork Chop, loin, cooked, 3 ounces – 2.9 mg
- baked beans, canned, ½ cup – 2.9 mg
- Chicken, dark meat, cooked, 3 ounces – 2.4 mg
- Yogurt, fruit, low fat, 8 ounces -1.7 mg
- Cashews, dry roasted, 1 ounce – 1.6 mg
- Chickpeas, cooked, ½ cup – 1.3 mg
- Cheese, Swiss, 1 ounce - 1.2 mg
- Oatmeal, instant plain prepared with water, 1 packet – 1.1 mg
- Milk, low fat or non fat, 1 cup - `1 mg
- Almonds, dry roasted, 1 ounce – 0.9 mg
- Kidney beans, cooked, 1/2cup - 0.9 mg
- Chicken breast, roasted, skin removed, ½ breast - 0.9 mg
- Cheese, cheddar or mozzarella, 1 ounce – 0.9 mg
- Peas, green, frozen, cooked, ½ cup – 0.5 mg
- Flounder or sole, cooked, 3 ounces – 0.3 mg
Best Forms of Zinc Supplements to Achieve Benefits of Zinc
Amino acid zinc chelate, zinc citrate, and zinc picolinate are preferable to zinc sulfate or or zinc oxide, because they contain greater amounts of elemental zinc.
When buying supplements, look for the amount of elemental zinc on the label and remember to count your dietary intake in your total daily zinc intake.
Cautions when taking Zinc Supplements – Ensuring you get the Benefits of Zinc and avoid the Hazards
Like with all minerals, don’t overdo it. Zinc is a trace mineral and should not be taken in excess or the benefits of zinc, like those of all dietary minerals, can transform into health hazards. Dietary minerals operate in ratio with other minerals in the body – an excess of one can deplete others and vice versa.
The tolerable upper intake level (UL) for adults age 19 and over is 40 mg, although your health care provider may have you on higher levels to correct deficiencies or treat other medical conditions. He or she will monitor your intake.
Chronic high levels 150 - 450 mg per day have been linked to low copper stores, iron dysfunction, reduced immunity. Long term intake of 80 mg per day have been associated with urinary problems.
Signs of zinc toxicity include the following:
- Loss of appetite
- Gastro-intestinal upset
Knowing when you are Zinc Deficient
Because of the blood’s tendency to remain within normal range for many substances (serum homeostasis), despite possible deficiency elsewhere in the body, blood tests have limited value for determining zinc status, except in cases of severe deficiency.
Many practitioners rely on clinical symptoms of zinc deficiency (See Above) and tracking dietary and supplemental zinc intake along with possible nutrients or medications that may reduce zinc absorption or zinc loss.
While considered experimental by many traditional doctors, tissue hair mineral analysis is a means of assessing zinc intake that has become more accurate and accepted than previously.
Hair is considered a good way to measure long term mineral intake. The hair shaft is similar to the rings on a tree, tracking environmental effects on growth over the long term; hair likewise provides evidence of the body’s mineral status over time.
The results of tissue hair analysis take skill to interpret, because it is often the ratio of minerals to one another that is as important as an outright deficiency of one. As well, the presence of heavy metals, that can reduce the function of certain dietary minerals including zinc, must be assessed. Indeed most labs test for the presence of a range of dietary minerals along with heavy metals.
Here is an example of the results of Tissue Hair Mineral Analysis.
If wanting tissue hair analysis, find a practitioner who uses a lab that does not wash the hair prior to analyzing. Apparently washing the hair before testing removes some of the minerals and leads to inaccurate results. As well permed or chemically treated hair is not suitable for hair analysis because the chemicals will skew the results.
Remember that zinc is a mineral you need for good health. Make sure you get enough in your diet in order to take advantage of the many health benefits zinc offers!