Zinc is an essential mineral that plays a vital role in numerous bodily functions, from boosting your immune system to supporting cell growth. Ensuring you get enough zinc through your diet is crucial for maintaining overall health and well-being. This guide, crafted by the culinary experts at foods.edu.vn, will explore the top Food Of Zinc sources, helping you to incorporate this important nutrient into your daily meals.
Zinc is a powerhouse mineral involved in countless aspects of your cellular metabolism. It’s not just a minor player; zinc is necessary for the activity of hundreds of enzymes that catalyze biochemical reactions in your body. Beyond enzymes, zinc is a key contributor to a robust immune system, the synthesis of proteins and DNA, efficient wound healing, and effective cell signaling and division [1-4]. Furthermore, zinc is indispensable for healthy growth and development throughout life, starting from pregnancy and infancy, continuing through childhood and adolescence, and even influencing your sense of taste [2,3,5].
Did you know that your body holds a significant amount of zinc? Women typically have around 1.5 grams, while men average about 2.5 grams [2]. The majority of this zinc is stored strategically in your skeletal muscles and bones, ready to be utilized when needed [1-3].
Your body is remarkably efficient at maintaining zinc balance, a process known as homeostasis. This involves carefully regulating zinc absorption from the foods you eat, excretion through the gastrointestinal tract, and reabsorption within the intestinal lumen [2,3]. Interestingly, as you consume more zinc, your body adapts by absorbing a greater amount, although the percentage of zinc absorbed may slightly decrease [2,3].
Clinicians often assess zinc status by measuring serum or plasma zinc levels. For healthy individuals, the normal range is between 80 to 120 mcg/dL (or 12 to 18 mcmol/L) [2]. Levels below 70 mcg/dL in women and 74 mcg/dL in men may indicate insufficient zinc. However, it’s important to note that these measurements have limitations. Serum zinc levels can be influenced by factors like sex, age, time of day, and may not always directly reflect dietary zinc intake [6]. Other factors such as infections, hormonal changes, and muscle breakdown can also cause fluctuations in zinc levels [1,3]. Therefore, healthcare professionals consider various risk factors, such as inadequate calorie intake, chronic alcohol use, and digestive disorders, along with signs of zinc deficiency like impaired growth in children, when evaluating a person’s zinc status [1].
Daily Zinc Requirements: How Much Food of Zinc Do You Need?
To help you understand your daily zinc needs, health authorities have established Recommended Dietary Allowances (RDAs) as part of the Dietary Reference Intakes (DRIs). These guidelines, developed by experts at the Food and Nutrition Board (FNB) at the National Academies of Sciences, Engineering, and Medicine, are essential for planning and evaluating nutrient intake for healthy populations [1]. The DRI encompasses various reference values tailored to different life stages and sexes, including:
- Recommended Dietary Allowance (RDA): This is the average daily intake level sufficient to meet the nutrient needs of almost all (97%–98%) healthy individuals. It’s a target often used for planning nutritionally sound diets for individuals.
- Adequate Intake (AI): When there’s not enough evidence to set an RDA, an AI is established. This level is assumed to ensure nutritional adequacy.
- Estimated Average Requirement (EAR): This is the daily intake level estimated to meet the needs of 50% of healthy individuals. It’s primarily used to assess nutrient intakes of groups and plan adequate diets for them, but can also be used for individuals.
- Tolerable Upper Intake Level (UL): This is the maximum daily intake that’s unlikely to cause adverse health effects. It’s crucial for preventing overconsumption.
Table 1: Recommended Dietary Allowances (RDAs) for Zinc [1]
| Age Group | Male (mg) | Female (mg) | Pregnancy (mg) | Lactation (mg) |
|---|---|---|---|---|
| Birth to 6 months* | 2 | 2 | ||
| 7–12 months | 3 | 3 | ||
| 1–3 years | 3 | 3 | ||
| 4–8 years | 5 | 5 | ||
| 9–13 years | 8 | 8 | ||
| 14–18 years | 11 | 9 | 12 | 13 |
| 19+ years | 11 | 8 | 11 | 12 |
*Adequate Intake (AI), equivalent to the mean intake of zinc in healthy, breastfed infants.
Top Food Sources of Zinc: Fueling Your Body Naturally
When it comes to obtaining zinc through your diet, food of zinc from various sources can effectively meet your nutritional needs. The most concentrated food sources of zinc are predominantly found in animal products, including meat, fish, and seafood [3]. While oysters are exceptionally high in zinc per serving, beef is a significant contributor to zinc intake in many diets due to its widespread consumption [7]. Eggs and dairy products also offer valuable amounts of zinc [3].
A serving of raw oysters, a top food of zinc, providing a substantial amount of this essential mineral.
Plant-based sources like beans, nuts, and whole grains also contain zinc, but it’s important to note that the zinc from these foods is less bioavailable compared to animal sources. This is because these plant-based foods contain phytates. Phytates, which are the storage form of phosphorus in plants, can bind to minerals like zinc in the intestine, forming an insoluble complex that hinders zinc absorption [1-3,8]. Fruits and vegetables, on the other hand, typically contain very little zinc.
Breakfast cereals are often fortified with zinc, making them a significant source of this mineral, especially in countries like the United States [3]. In fact, fortified cereals contribute a notable percentage of daily zinc intake among children and adolescents in the U.S. [9].
The amount of zinc your body absorbs from food varies considerably, ranging from as low as 5% to over 50%. This variability is largely influenced by the proportion of plant-based foods, and consequently phytates, in your diet [3]. Diets that are a mix of both animal and plant-based foods result in lower zinc absorption compared to diets primarily composed of animal-based foods [10].
For a detailed look at specific foods and their zinc content, refer to Table 2, which lists a variety of food of zinc and their zinc content per serving [11].
Table 2: Zinc Content of Selected Foods [11]
| Food | Milligrams (mg) per serving | Percent DV* |
|---|---|---|
| Oysters, Eastern, farmed, raw, 3 ounces | 32 | 291 |
| Oysters, Pacific, cooked, 3 ounces | 28.2 | 256 |
| Beef, bottom sirloin, roasted, 3 ounces | 3.8 | 35 |
| Blue crab, cooked, 3 ounces | 3.2 | 29 |
| Breakfast cereals, fortified with 25% of the DV for zinc, 1 serving | 2.8 | 25 |
| Cereals, oats, regular and quick, unenriched, cooked with water, 1 cup | 2.3 | 21 |
| Pumpkin seeds, roasted, 1 ounce | 2.2 | 20 |
| Pork, center loin (chops), bone in, broiled, 3 ounces | 1.9 | 17 |
| Turkey breast, meat only, roasted, 3 ounces | 1.5 | 14 |
| Cheese, cheddar, 1.5 ounces | 1.5 | 14 |
| Shrimp, cooked, 3 ounces | 1.4 | 13 |
| Lentils, boiled, ½ cup | 1.3 | 12 |
| Sardines, canned in oil, drained solids with bone, 3 ounces | 1.1 | 10 |
| Greek yogurt, plain, 6 ounces | 1.0 | 9 |
| Milk, 1% milkfat, 1 cup | 1.0 | 9 |
| Peanuts, dry roasted, 1 ounce | 0.8 | 7 |
| Rice, brown, long grain, cooked, ½ cup | 0.7 | 6 |
| Egg, large, 1 | 0.6 | 5 |
| Kidney beans, canned, ½ cup | 0.6 | 5 |
| Bread, whole wheat, 1 slice | 0.6 | 5 |
| Fish, salmon, cooked, 3 ounces | 0.5 | 5 |
| Broccoli, chopped, cooked, ½ cup | 0.4 | 4 |
| Rice, white, long grain, cooked, ½ cup | 0.3 | 3 |
| Bread, white, 1 slice | 0.2 | 2 |
| Cherry tomatoes, raw, ½ cup | 0.1 | 1 |
| Blueberries, raw, ½ cup | 0.1 | 1 |
*DV = Daily Value. The U.S. Food and Drug Administration (FDA) has set a Daily Value (DV) for zinc at 11 mg for adults and children age 4 years and older to help consumers understand nutrient content in the context of a total daily diet [12]. While food labels aren’t required to list zinc unless it’s added, foods providing 20% or more of the DV are considered high sources, and even smaller percentages contribute to a healthy dietary pattern.
For more comprehensive information on the nutrient content of various foods, including zinc, you can explore the U.S. Department of Agriculture’s (USDA’s) FoodData Central (https://fdc.nal.usda.gov/). They also provide detailed lists of food of zinc, categorized by nutrient content (https://ods.od.nih.gov/pubs/usdandb/Zinc-Content.pdf) and food name (https://ods.od.nih.gov/pubs/usdandb/Zinc-Food.pdf).
Zinc Supplements: An Alternative Source
In addition to food of zinc, dietary supplements are another way to increase your zinc intake. Zinc is available in various supplement forms, including those containing only zinc, combinations with other nutrients, and as part of multivitamin/mineral supplements [13]. Common forms of zinc in supplements include zinc sulfate, zinc acetate, and zinc gluconate [14]. It’s important to note that supplement labels list the amount of elemental zinc, not the total weight of the zinc compound.
Absorption rates can vary among different zinc supplement formulations. Zinc citrate and zinc gluconate are absorbed similarly, around 61% in young adults, while zinc oxide has a slightly lower absorption rate of about 50% [15]. Taking high doses of iron (25 mg or more of elemental iron) at the same time as zinc supplements can hinder zinc absorption [16-19]. However, iron added to fortified foods does not seem to interfere with zinc absorption.
Are You Getting Enough Zinc? Assessing Zinc Intakes and Status
Most people in the United States generally consume sufficient zinc. However, certain demographics, particularly older adults, may have marginal zinc intakes. On average, daily zinc intake from foods ranges from 7.6–9.7 mg/day for children aged 2–11 years, 10.1 mg/day for those aged 12–19 years, approximately 13 mg/day for men over 19, and around 9.2 mg/day for women [24]. When considering both food and supplements, the average daily intake increases slightly across these groups [24, 25].
Despite these averages, some segments of the population are at risk of inadequate zinc intake. Data indicates that a small percentage of young children have intakes below the EAR, while a more significant portion of teenage girls and older adults fall below recommended levels [9, 26]. Zinc deficiency, as indicated by low serum zinc concentrations, is also observed in a percentage of children and adults in the U.S. [6, 8].
Zinc deficiency based on serum or plasma concentrations is a more widespread issue in low- and middle-income countries [27]. Global estimates suggest that a substantial portion of the world’s population may be affected by zinc deficiency, highlighting the importance of addressing zinc nutrition worldwide [28].
Understanding Zinc Deficiency: Risks and Symptoms
Zinc deficiency, stemming from inadequate food of zinc intake or absorption, can have far-reaching effects throughout the body due to zinc’s extensive roles in various biological processes [29]. This deficiency can impact numerous tissues and organs, including the skin, bones, and digestive, reproductive, central nervous, and immune systems [29].
The signs of zinc deficiency can vary depending on age [29]. Infants and children may commonly experience diarrhea. In older children, symptoms can include hair loss (alopecia), delayed growth, and increased susceptibility to infections. In both age groups, zinc deficiency can impair growth and potentially lead to appetite loss and reproductive issues in adulthood [2, 3, 27, 30]. In populations with limited access to readily absorbable zinc from animal sources, zinc deficiency poses significant health risks for pregnant women and their infants, increasing the likelihood of complications like premature birth, low birth weight, and maternal morbidity [27]. Furthermore, zinc deficiency can impair the senses of taste and smell [5]. Older adults with zinc deficiency may experience delayed wound healing and changes in cognitive and psychological function [29].
Groups at Higher Risk of Zinc Deficiency: Who Needs to Pay Extra Attention to Food of Zinc?
Certain groups are more susceptible to zinc inadequacy due to various factors, making it crucial for them to prioritize food of zinc and ensure adequate intake.
Individuals with Gastrointestinal Disorders or Bariatric Surgery
Zinc deficiency is frequently observed in individuals with inflammatory bowel disease (IBD), such as ulcerative colitis and Crohn’s disease, or those who have undergone bariatric surgery involving gastrointestinal resection. This increased risk is attributed to factors like poor dietary intake, reduced absorption, or increased urinary zinc excretion resulting from inflammation [31, 32]. Studies indicate that a significant percentage of IBD patients experience zinc deficiency, which may exacerbate IBD symptoms and increase the risk of complications [31, 32]. Similarly, a substantial proportion of newly diagnosed celiac disease patients are at risk of zinc deficiency, potentially due to malabsorption and mucosal inflammation [33, 34]. These deficiencies can sometimes persist even with a gluten-free diet [34].
Vegetarians and Vegans
Vegetarian and vegan diets, while healthful, often have lower zinc bioavailability compared to non-vegetarian diets. This is primarily because plant-based diets typically include higher amounts of legumes and whole grains, which contain phytates that inhibit zinc absorption [2, 35]. Additionally, meat, a rich source of bioavailable zinc, is excluded from these diets [35]. Consequently, vegetarians and vegans tend to have lower dietary zinc intakes and serum zinc levels than meat-eaters [36]. To enhance zinc absorption, vegetarians and vegans can employ food preparation techniques like soaking beans, grains, and seeds before cooking [37]. Fermented foods may also improve zinc absorption due to the presence of organic acids [37]. Zinc supplements might be beneficial for vegetarians and vegans to ensure adequate intake [38].
Pregnant and Lactating Women
Pregnancy significantly increases zinc requirements to support fetal development. Health guidelines recommend that pregnant women consume more zinc than non-pregnant women of the same age [1, 3]. Lactation also elevates zinc needs. Data suggests that a notable percentage of pregnant women may have zinc intakes below the EAR [25]. While routine zinc supplementation during pregnancy may not reduce all risks, it might lower the risk of preterm birth [41]. During lactation, the impact of zinc-rich foods on breast milk zinc levels is still being researched, with some studies showing positive effects [42, 43] and others showing mixed results [44, 45, 46].
Older Breastfed Infants
Zinc levels in breast milk naturally decline after the first month of lactation [3]. After 6 months of age, breast milk alone may not provide sufficient zinc for infants [3, 47]. Therefore, it’s recommended that infants aged 7–12 months receive zinc-containing foods or formula in addition to breast milk [1].
Children with Sickle Cell Disease
Children with sickle cell disease (SCD) are at increased risk of zinc deficiency, possibly due to chelation therapy used to manage iron overload [3, 48]. Zinc deficiency in children with SCD can contribute to growth delays and other health complications [48]. Zinc supplementation may promote growth and reduce the risk of infections and other SCD-related issues in these children [3, 48, 49].
Individuals with Alcohol Use Disorder
Alcohol use disorder is often associated with low zinc status. Ethanol consumption can impair intestinal zinc absorption and increase urinary zinc excretion [1, 50, 51, 52]. Furthermore, dietary habits in individuals with alcohol use disorder may lead to inadequate zinc intake [53, 54].
Zinc and Specific Health Conditions: Exploring the Potential Benefits Beyond Basic Nutrition
Zinc, obtained through food of zinc and supplements, has been studied for its potential role in managing various health conditions. While more research is often needed, current findings suggest potential benefits in the following areas:
The Common Cold
Research suggests that zinc may help reduce the duration of cold symptoms by interfering with rhinovirus activity and reducing inflammation [55, 56]. Studies on zinc supplements for colds have shown mixed results, but some indicate that zinc lozenges or syrups, when taken soon after cold onset, may shorten the duration of colds [57-60]. However, more research is needed to determine optimal dosage and formulation [58-60].
Pneumonia in Children
Pneumonia remains a major cause of childhood mortality, especially in low-income countries [63]. Zinc status is linked to pneumonia susceptibility and severity [64-67]. Some studies suggest that zinc supplementation in zinc-deficient populations may reduce pneumonia incidence [63]. However, the use of zinc supplements as an adjunctive treatment for pneumonia is still under investigation, with findings varying across studies [68, 69].
HIV Infection
HIV infection can affect zinc absorption and metabolism, and people with HIV are often prone to diarrhea, leading to zinc loss [3]. Studies exploring zinc supplementation in HIV-positive individuals have shown some potential benefits, such as reduced rates of opportunistic infections and diarrhea in some trials [70, 71]. However, other studies and reviews have yielded less conclusive results, and more research is needed to clarify the role of zinc supplementation in managing HIV [72-75].
Childhood Acute Diarrhea
Acute diarrhea is a significant health concern for children in low-income countries [76, 77]. Zinc is recognized as a treatment for acute diarrhea, particularly in zinc-deficient regions, due to its role in immune function and gut health [76]. Clinical trials indicate that zinc supplementation can shorten the duration of diarrhea in children, especially in those over 6 months old and those with malnutrition [78, 79]. Organizations like WHO and UNICEF recommend zinc supplementation as part of childhood diarrhea management in areas where deficiency is prevalent [80].
Age-Related Macular Degeneration (AMD)
AMD is a leading cause of vision loss in older adults [81]. The retina has a high zinc concentration, and studies suggest that zinc, often combined with antioxidants, may help slow AMD progression [3, 82, 83]. Observational studies have linked higher zinc intakes to a lower risk of AMD [84, 85]. The Age-Related Eye Disease Study (AREDS) and AREDS2 trials have demonstrated the benefits of supplements containing zinc and antioxidants in slowing AMD progression [83, 86]. Eye health organizations often recommend AREDS formulations containing zinc for individuals at risk of or with AMD [87, 88].
Type 2 Diabetes
Zinc levels are often lower in people with type 2 diabetes (T2D) [2, 3]. Research is exploring the potential role of zinc in diabetes management. Observational studies suggest a possible link between higher zinc intakes and reduced T2D risk [89]. Clinical trials investigating zinc supplementation for T2D have shown some promising results, including improvements in lipid profiles and glycemic control [90-94]. However, more research is needed to fully understand the impact of zinc supplementation on T2D prevention and management [90, 96].
Potential Health Risks of Excessive Zinc Intake: Understanding the Upper Limits
While zinc is essential, excessive intake can lead to adverse health effects. High zinc doses, typically from supplements or overuse of zinc-containing denture creams, can cause nausea, dizziness, and other gastrointestinal issues [2, 3]. Long-term excessive zinc intake can interfere with copper absorption, potentially leading to copper deficiency, impaired immune function, and reduced HDL cholesterol levels [1-3, 97]. Extremely high doses might also disrupt magnesium balance [98].
To prevent overconsumption, the FNB has established Tolerable Upper Intake Levels (ULs) for zinc from both food of zinc and supplements. These ULs are based on levels that could negatively affect copper status and are shown in Table 3 [1]. It’s important to note that these ULs do not apply to individuals receiving zinc under medical supervision.
Table 3: Tolerable Upper Intake Levels (ULs) for Zinc [1]
| Age Group | Male (mg) | Female (mg) | Pregnancy (mg) | Lactation (mg) |
|---|---|---|---|---|
| Birth to 6 months | 4 | 4 | ||
| 7–12 months | 5 | 5 | ||
| 1–3 years | 7 | 7 | ||
| 4–8 years | 12 | 12 | ||
| 9–13 years | 23 | 23 | ||
| 14–18 years | 34 | 34 | 34 | 34 |
| 19+ years | 40 | 40 | 40 | 40 |
Potential Interactions with Medications: Be Aware of Combined Effects
Zinc can interact with certain medications, and conversely, some medications can affect zinc levels in the body. If you are taking any medications regularly, it’s important to discuss your zinc intake with your healthcare provider.
Antibiotics
Quinolone antibiotics (like Cipro) and tetracycline antibiotics (like Achromycin and Sumycin) can interact with zinc in the gastrointestinal tract, potentially reducing the absorption of both zinc and the antibiotic if taken concurrently [99, 100]. To minimize this interaction, it’s recommended to take the antibiotic at least 2 hours before or 4–6 hours after a zinc supplement [99].
Penicillamine
Zinc can decrease the absorption and effectiveness of penicillamine, a medication used to treat rheumatoid arthritis and Wilson disease [101]. To avoid this interaction, zinc supplements and penicillamine should be taken at least 1 hour apart.
Diuretics
Thiazide diuretics, such as chlorthalidone (Hygroton and Thalitone) and hydrochlorothiazide (e.g., Esidrix and HydroDIURIL), can increase zinc excretion through urine, which may lead to decreased serum zinc concentrations [102].
Incorporating Food of Zinc into a Healthful Diet
The 2020–2025 Dietary Guidelines for Americans emphasizes obtaining nutrients primarily from food of zinc and other nutrient-rich foods. While fortified foods and supplements can be useful in certain situations, a balanced dietary pattern is key for overall health.
The Dietary Guidelines recommends a healthy eating pattern that includes:
- A variety of vegetables, fruits, whole grains, and fat-free or low-fat dairy and dairy products. Dairy products and fortified cereals can be good food of zinc sources.
- A variety of protein foods, including seafood, lean meats, poultry, eggs, legumes, nuts, seeds, and soy products. Meat, fish, and seafood are excellent food of zinc choices.
- Limiting foods high in added sugars, saturated fat, and sodium.
- Limiting alcoholic beverages.
- Staying within your daily calorie needs.
For more detailed guidance on creating a healthy dietary pattern, refer to the Dietary Guidelines for Americans and the USDA’s MyPlate. By focusing on incorporating a variety of food of zinc into your meals, you can ensure you are meeting your daily requirements for this essential mineral and supporting your overall health.
References
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Disclaimer
This information is for educational purposes and should not be considered medical advice. Consult with a healthcare professional for personalized dietary guidance and health recommendations.
