Zinc in Needed Throughout Life
Zinc also supports normal growth and development during pregnancy, childhood, and adolescence and is required for proper sense of taste and smell. A daily intake of zinc is required to maintain a steady state because the body has no specialized zinc storage system.
Zinc Deficiency
Zinc deficiency is characterized by growth retardation, loss of appetite, and impaired immune function. In more severe cases, zinc deficiency causes hair loss, diarrhea, delayed sexual maturation, impotence, hypogonadism in males, and eye and skin lesions.
Weight loss, delayed healing of wounds, taste abnormalities, and mental lethargy can also occur. Many of these symptoms are non-specific and often associated with other health conditions; therefore, a medical examination is necessary to ascertain whether a zinc deficiency is present.
Zinc nutritional status is difficult to measure adequately even in laboratory tests because of its distribution throughout the body as a component of various proteins and nucleic acids.
Plasma or serum zinc levels are the most commonly used indices for evaluating zinc deficiency, but these levels do not necessarily reflect cellular zinc status due to tight homeostatic control mechanisms. Clinical effects of zinc deficiency can be present in the absence of abnormal laboratory indices. Clinicians consider risk factors (such as inadequate caloric intake, alcoholism, and digestive diseases) and symptoms of zinc deficiency (such as impaired growth in infants and children) when determining the need for zinc supplementation.
- 60 years+
- Risk Groups
- Minerals Inbalance
- Drugs & Zinc
- Vanadium Deficiency
Zinc Deficiency
Evidence suggests that zinc intakes among older adults might be marginal. An analysis of National Health and Nutrition Examination Survey
(NHANES) III data found that 35%–45% of adults aged 60 years or older had zinc intakes below the estimated average requirement of 6.8 mg/day for elderly females and 9.4 mg/day for elderly males. When the investigators considered intakes from both food and dietary supplements, they found that 20%–25% of older adults still had inadequate zinc intakes.
Zinc intakes might also be low in older adults from the 2%–4% of U.S. households that are food insufficient (sometimes or often not having enough food). Data from NHANES III indicate that adults aged 60 years or older from food-insufficient families had lower intakes of zinc and several other nutrients and were more likely to have zinc intakes below 50% of the RDA on a given day than those from food-sufficient families.
Groups at Risk for Zinc Inadequacy
When zinc deficiency does occur, it is usually due to inadequate zinc intake or absorption, increased losses of zinc from the body, or increased requirements for zinc.
People with gastrointestinal and other diseases:
Gastrointestinal surgery and digestive disorders (such as ulcerative colitis, Crohn’s disease, and short bowel syndrome) can decrease zinc absorption and increase endogenous zinc losses primarily from the gastrointestinal tract and, to a lesser extent, from the kidney.
sDiseases associated with zinc deficiency include:
Malabsorption syndrome
Chronic liver disease
Chronic renal disease
Sickle cell disease
Diabetes
Malignancy, and other chronic illnesses.
Chronic diarrhea also leads to excessive loss of zinc.
A Balanced Approach in Need with Mineral Supplementation
Zinc toxicity can occur in both acute and chronic forms. Acute adverse effects of high zinc intake include nausea, vomiting, loss of appetite, abdominal cramps, diarrhea, and headaches. One case report cited severe nausea and vomiting within 30 minutes of ingesting 4 g of zinc gluconate (570 mg elemental zinc). Intakes of 150–450 mg of zinc per day have been associated with such chronic effects as low copper status, altered iron function, reduced immune function, and reduced levels of high-density lipoproteins. Reductions in a copper-containing enzyme, a marker of copper status, have been reported with even moderately high zinc intakes of approximately 60 mg/day for up to 10 weeks. Doses of 80 mg per day of zinc in the form of zinc oxide for 6.3 years, on average have been associated with a significant increase in hospitalizations for genitourinary causes, raising the possibility that chronically high intakes of zinc adversely affect some aspects of urinary physiology.
The FNB has established ULs for zinc (Table 3). Long-term intakes above the UL increase the risk of adverse health effects. The ULs do not apply to individuals receiving zinc for medical treatment, but such individuals should be under the care of a physician who monitors them for adverse health effects.
Interactions with Medications
Zinc supplements have the potential to interact with several types of medications. A few examples are provided below. Individuals taking these medications on a regular basis should discuss their zinc intakes with their healthcare providers.
Antibiotics
Both quinolone antibiotics (such as Cipro®) and tetracycline antibiotics (such as Achromycin® and Sumycin®) interact with zinc in the gastrointestinal tract, inhibiting the absorption of both zinc and the antibiotic. Taking the antibiotic at least 2 hours before or 4–6 hours after taking a zinc supplement minimizes this interaction.
Penicillamine
Zinc can reduce the absorption and action of penicillamine, a drug used to treat rheumatoid arthritis. To minimize this interaction, individuals should take zinc supplements at least 2 hours before or after taking penicillamine.
Diuretics
Thiazide diuretics such as chlorthalidone (Hygroton®) and hydrochlorothiazide (Esidrix® and HydroDIURIL®) increase urinary zinc excretion by as much as 60%. Prolonged use of thiazide diuretics could deplete zinc tissue levels, so clinicians should monitor zinc status in patients taking these medications.
Recommended Intakes
Intake recommendations for zinc and other nutrients are provided in the Dietary Reference Intakes (DRIs) developed by the Food and Nutrition Board (FNB) at the Institute of Medicine. DRI is the general term for a set of reference values used for planning and assessing nutrient intakes of healthy people. These values, which vary by age and gender, include the following:
- Recommended Dietary Allowance (RDA): average daily level of intake sufficient to meet the nutrient requirements of nearly all (97%–98%) healthy individuals.
- Adequate Intake (AI): established when evidence is insufficient to develop an RDA and is set at a level assumed to ensure nutritional adequacy.
- Tolerable Upper Intake Level (UL): maximum daily intake unlikely to cause adverse health effects.
Sources of Zinc
- Food
- Phylic Acid/ stops zinc
- Zinc In Foood
Food
A wide variety of foods contain zinc.
Oysters contain more zinc per serving than any other food, but red meat and poultry provide the majority of zinc in the American diet. Other good food sources include beans, nuts, certain types of seafood (such as crab and lobster), whole grains, fortified breakfast cereals, and dairy products.
Phylic Acid
The amount of Phylic Acid found in vegetables used as a chelation agent for zinc and other minerals:
Tofu ............................................................1.46 - 2.90
Linseed......................................................... 2.15 2.78
Oat Meal ......................................................0.89 2.40
Soy flour .......................................................1.24 2.25
Soybeans ......................................................1.00 2.22
Corn .............................................................0.75 2.22
Peanuts .........................................................1.05 1.76
Kidney beans................................................ 0.89 1.57
Rye ..............................................................0.54 1.46
Oat bran ......................................................0.60 1.42
Wheat flour ..................................................0.25 1.37
Wheat ..........................................................0.39 1.35
Oat ..............................................................0.42 1.16
Barley .........................................................0.38 1.16
Whole wheat bread ......................................0.43 1.05
Polished rice ................................................0.14 0.60
Selected Food Sources of Zinc
Food |
Milligrams (mg)
per serving |
Percent DV* |
Oysters, 6 medium |
76.7 |
513 |
Beef shanks, cooked, 3 ounces |
8.9 |
59 |
Crab, Alaska king, cooked, 3 ounces |
6.5 |
43 |
Pork shoulder, cooked, 3 ounces |
4.2 |
28 |
Breakfast cereal fortified with 25% of the DV for zinc, ¾ cup serving |
3.8 |
25 |
Chicken leg, roasted, 1 leg |
2.7 |
18 |
Pork tenderloin, cooked, 3 ounces |
2.5 |
17 |
Lobster, cooked, 3 ounces |
2.5 |
17 |
Baked beans, canned, ½ cup |
1.7 |
11 |
Cashews, dry roasted, 1 ounce |
1.6 |
11 |
Yogurt, fruit, low fat, 1 cup |
1.6 |
11 |
Raisin bran, ¾ cup |
1.3 |
9 |
Chickpeas, ½ cup |
1.3 |
9 |
Cheese, Swiss, 1 ounce |
1.1 |
7 |
Almonds, dry roasted, 1 ounce |
1.0 |
7 |
Milk, 1 cup |
0.9 |
6 |
Chicken breast, roasted, ½ breast with skin removed |
0.9 |
6 |
Cheese, cheddar or mozzarella, 1 ounce |
0.9 |
6 |
Kidney beans, cooked, ½ cup |
0.8 |
5 |
Peas, boiled, ½ cup |
0.8 |
5 |
Oatmeal, instant, 1 packet |
0.8 |
5 |
Flounder or sole, cooked, 3 ounces |
0.5 |
3 |
The U.S. Department of Agriculture’s Nutrient Database Web site, http://www.nal.usda.gov/fnic/foodcomp/search/ , lists the nutrient content of many foods and provides a comprehensive list of foods containing zinc:
http://www.nal.usda.gov/fnic/foodcomp/Data/SR20/nutrlist/sr20w309.pdf. |
- Vegans
- Carbohydrates / Sugar
- Pregnant
- Lactation
- Older infants
Vegans
Vegans/herbivores typically have lower zinc concentration in their body tissues, leading to decreased height and other neurological issues. Bio-available zinc is lower in vegan diets than from Omnivores diets. However vegetarians to tend to eat fish and sea-food, which means they really are omnivores that prefer non-mammal sources of protein which can contain high zinc concentrations. Vegetarians also typically eat high levels of legumes and whole grains, but these contain phytates that bind zinc and inhibit its absorption into the body.
Vegetarians and vegans sometimes require as much as 50% more of the recommended RDA for zinc than non-omnivores. In addition, they might benefit from using certain food preparation techniques that reduce the binding of zinc by phytates and increase its bioavailability. Techniques to increase zinc bioavailability include soaking beans, grains, and seeds in water for several hours before cooking them and allowing them to sit after soaking until sprouts form. Vegans can also increase their zinc intake by consuming more leavened grain products (such as bread) than unleavened products (such as crackers) because leavening partially breaks down the phytate; thus, the body absorbs more zinc from leavened grains than unleavened grains, but one need to also understand that when one increases the grain they also increase the concentration of sugar in their body.
Carbohydrates and Sugar
When we chew, our body releases amylase into the saliva thus allowing the chemical change from carbohydrate to sugar to begin. This is a concern to people concerned about weight gain, cancer patients, and people with type one and two diabetes. If one has a metabolic deficiency the increase in sugar can lead to acidosis. When one’s body is imbalanced from hyper- or hypo-mineralizing, demineralization can occur, leading to heart disease, diabetes, and other disease and conditions.
Pregnant
Pregnant women, particularly those starting their pregnancy with marginal zinc status, are at increased risk of becoming zinc insufficient due, in part, to high fetal requirements for zinc.
Lactation
Lactation can also deplete maternal zinc stores.
For these reasons, the RDA for zinc is higher for pregnant and lactating women than for other women..
Older infants
Older infants who are exclusively breastfed
Breast milk provides sufficient zinc (2 mg/day) for the first 4–6 months of life but does not provide recommended amounts of zinc for infants aged 7–12 months, who need 3 mg/day. In addition to breast milk, infants aged 7–12 months should consume age-appropriate foods containing zinc. Zinc supplementation has improved the growth rate in some children who demonstrate mild-to-moderate growth failure and who have a zinc deficiency.
Zinc the Anti-cancer mineral
The World Health Organization and UNICEF now recommend short-term zinc supplementation (20 mg of zinc per day, or 10 mg for infants under 6 months, for 10–14 days) to treat acute childhood diarrhea.
The common cold
The effect of zinc treatment on the severity or duration of cold symptoms is controversial. Researchers have hypothesized that zinc directly inhibits rhinovirus binding and replication in the nasal mucosa and suppresses inflammation. However, no data are available to support this hypothesis.
In a randomized, double-blind, placebo-controlled clinical trial, 50 subjects (within 24 hours of developing the common cold) took a zinc acetate lozenge (13.3 mg zinc) or placebo every 2–3 wakeful hours. Compared with placebo, the zinc lozenges significantly reduced the duration of cold symptoms (cough, nasal discharge, and muscle aches).
In another clinical trial involving 273 participants with experimentally induced colds, zinc gluconate lozenges (providing 13.3 mg zinc) significantly reduced the duration of illness compared with placebo but had no effect on symptom severity. However, treatment with zinc acetate lozenges (providing 5 or 11.5 mg zinc) had no effect on either cold duration or severity. Neither zinc gluconate nor zinc acetate lozenges affected the duration or severity of cold symptoms in 281 subjects with natural (not experimentally induced) colds in another trial.
In 77 participants with natural colds, a combination of zinc gluconate nasal spray and zinc orotate lozenges (37 mg zinc every 2–3 wakeful hours) was also found to have no effect on the number of asymptomatic patients after 7 days of treatment.
Caruso et. al., (2007) published a structured review of the effects of zinc lozenges, nasal sprays, and nasal gels on the common cold. Of the 14 randomized, placebo-controlled studies included, 7 (5 using zinc lozenges, 2 using a nasal gel) showed that the zinc treatment had a beneficial effect and 7 (5 using zinc lozenges, 1 using a nasal spray, and 1 using lozenges and a nasal spray) showed no effect. Researches have concluded that zinc can reduce the duration and severity of cold symptoms.
Age-related macular degeneration
Researchers have suggested that both zinc and antioxidants delay the progression of age-related macular degeneration (AMD) and vision loss, possibly by preventing cellular damage in the retina. In a population-based cohort study in the Netherlands, high dietary intake of zinc as well as beta carotene, vitamin C, and vitamin E was associated with reduced risk of AMD in elderly subjects.
Interactions with Iron & Copper
Iron-deficiency anemia is a serious world-wide public health problem. Iron fortification programs have been credited with improving the iron status of millions of women, infants, and children. Fortification of foods with iron does not significantly affect zinc absorption. However, large amounts of supplemental iron (greater than 25 mg) might decrease zinc absorption. Taking iron supplements between meals helps decrease its effect on zinc absorption.
High zinc intakes can inhibit copper absorption, sometimes producing copper deficiency and associated anemia.
Zinc and Healthful Diets
According to the 2005 Dietary Guidelines for Americans, "Nutrient needs should be met primarily through consuming foods. Foods provide an array of nutrients and other compounds that may have beneficial effects on health. In certain cases, fortified foods and dietary supplements may be useful sources of one or more nutrients that otherwise might be consumed in less than recommended amounts. However, dietary supplements, while recommended to people who show deficiency one should not assume that taking a multi mineral will improve their health. One needs to determine if they are in-fact deficient, before one starts on a hyper-mineralization diet.”
Eat the Very Best Foods- Organic, Natural, 80% Raw
Check to see if the foods you eat daily have the proper ratio of minerals and vitamins for a healthy life. One should daily self-diagnose using the “Classic signs of deficiency.” Example: White spots on one’s nails is one of the classic signs of zinc deficiency… noting these signs is a proactive approach to ones health.
Consider having hair analysis done to determine if you in-fact suffer from mineral toxicities, e.g., too much of one mineral or a heavy metal such as lead.
Consider mineral deficiencies; do you in fact have all the minerals and metal in your body to keep you healthy?
Keep in mind that your are an individual not a statistical norm on a chart.
- Sickle Cell
- Alcoholics
- Immune Function
- Wound Healing
- Diarrhea
People with sickle cell disease
Results from a large cross-sectional survey suggest that 44% of children with sickle cell disease have a low plasma zinc concentration, possibly due to increased nutrient requirements and/or poor nutritional status. Zinc deficiency also affects approximately 60%–70% of adults with sickle cell disease. Zinc supplementation has been shown to improve growth in children with sickle cell disease.
Alcoholics
Approximately 30%–50% of alcoholics have low zinc status because ethanol consumption decreases intestinal absorption of zinc and increases urinary zinc excretion.
Immune function
Severe zinc deficiency depresses immune function, and even mild to moderate degrees of zinc deficiency can impair macrophage and neutrophil functions, natural killer cell activity, and complement activity. The body requires zinc to develop and activate T-lymphocytes. Individuals with low zinc levels have shown reduced lymphocyte proliferation response to mitogens and other adverse alterations in immunity that can be corrected by zinc supplementation. These alterations in immune function might explain why low zinc status has been associated with increased susceptibility to pneumonia and other infections in children in developing countries and the elderly.
Wound healing
Zinc helps maintain the integrity of skin and mucosal membranes. Patients with chronic leg ulcers have abnormal zinc metabolism and low serum zinc levels, and clinicians frequently treat skin ulcers with zinc supplements. The authors of A Systematic Review concluded that zinc sulfate might be effective for treating leg ulcers in some patients who have low serum zinc levels. However, research has not shown that the general use of zinc sulfate in patients with chronic leg ulcers or arterial or venous ulcers is effective.
Diarrhea
Acute diarrhea is associated with high rates of mortality among children in developing countries. Zinc deficiency causes alterations in immune response that probably contribute to increased susceptibility to infections, such as those that cause diarrhea, especially in children.
Studies show that poor, malnourished children in India, Africa, South America, and Southeast Asia experience shorter courses of infectious diarrhea after taking zinc supplements. The children in these studies received 4–40 mg of zinc a day in the form of zinc acetate, zinc gluconate, or zinc sulfate.
In addition, results from a pooled analysis of randomized controlled trials of zinc supplementation in developing countries suggest that zinc helps reduce the duration and severity of diarrhea in zinc-deficient or otherwise malnourished children. Similar findings were reported in a meta-analysis published in 2008 and a 2007 review of zinc supplementation for preventing and treating diarrhea. The effects of zinc supplementation on diarrhea in children with adequate zinc status, such as most children in the United States, are not clear.
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