| Mineral Nutrient :: Zinc |
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What is Zinc ? Zinc is one of the essential micro-minerals that the body needs for growth and development, and to function properly. It is present in all cells in the body, though most highly concentrated in the skin, hair, nails, eyes, bone and liver, and in men in the prostate and semen. It is involved in stimulating over 100 different enzymes which control 300 biochemical reactions that sustain life. We need a small intake of it daily, as our bodies do not store zinc. Zinc is found in different forms in food. These vary widely in response to processing and cooking. Water-soluble forms are more prone to loss. For instance, almost half the zinc in beans is lost during cooking. It is also found in supplements, and in many cold lozenges and remedies. How Zinc Benefits Health Its role in the functioning of enzymes responsible for so many (over 300) bio-chemical processes in the body makes zinc vital to health. It is also a cofactor of superoxide dismutase (SOD), an important antioxidant enzyme. It is one of the nutrients that the body uses to maintain healthy skin and mucous membranes, and to rebuild damaged skin, which makes it useful for skin disorders such as acne, eczema, and psoriasis. It is especially known for fighting flu, colds, and infections. The many ways that zinc benefits the body are summarized here.
TOP Zinc Deficiency Symptoms and Causes Severe deficiency, especially among children and younger adults, is rare, but research shows that up to one-third of older adults have zinc intakes below the recommended daily requirements, despite the fact that zinc is available in common foods. At the same time, research is now showing that even mild deficiency can lead to health problems such as poor digestion, lower healing ability, lower resistance to disease, and other zinc deficiency symptoms. Low levels of zinc can be due to insufficient intake of foods containing zinc or to intestinal problems such as irritable bowel disorders that lead to poor absorption of nutrients, or inadequate output by the pancreas, preventing proper digestion. Birth control pills, caffeine, alcohol, dairy foods, and certain diuretics may reduce zinc absorption as well. Consume them separately from zinc. Zinc levels can also be lowered because of conditions that cause the body to need more zinc, or to excrete more of it, such as liver cirrhosis, chronic diarrhea, diabetes, excess fibre intake, drinking of hard water, and profuse sweating (as for instance from athletic training or manual labour). As foods high in zinc are mainly from animal sources, and the phytates in grains and legumes interfere with zinc absorption, those who don't eat red meat might need to take fortified cereals or supplements. The zinc deficiency symptoms that have been identified are tabled here.
TOP Zinc Foods Generally the best sources of zinc are high-protein foods. Plant-foods and grains are not considered good sources, as the bio-availability of the zinc in them is low. Phytates present in legumes and whole-grains tend to bind with zinc and inhibit its absorption. Apart from meat, most foods provide less than 10% of the recommended daily requirement per serving. Foods high in zinc are · liver · meat (beef, chicken, lamb, pork, venison) · mushrooms · raw oysters. Other foods containing zinc include · brewer's yeast · fortified breakfast cereals · fortified dairy products (milk, cheese, yogurt) · banana, durian · basil, thyme · egg yolks · fish · legumes (adzuki beans, baked beans, chickpeas, hyacinth beans, kidney beans, lima beans, green peas) · maple syrup · miso · nuts (almonds, cashews, peanuts, pecans, pine) · peanut butter · seeds (mustard, pumpkin, safflower, sesame, sunflower, and watermelon seeds) · sea-food (crab, lobster, shrimp) · seaweed such as dulse, kelp · soy lecithin · soybeans · vegetables (asparagus, broccoli, chard, collard greens, mustard greens, spinach, summer squash) · wheat germ · whole grains (brown rice, millet, oats, rye, wheat) · rice bran. TOP Zinc Supplements Taking vitamins and minerals in their correct balance is vital to the proper functioning of all vitamins. They work synergistically, which means that the effectiveness of any one nutrient requires, or is enhanced, sometimes dramatically, by the presence of certain other nutrients. For this reason, if you are looking to take supplements for maintenance of optimal health, the recommended approach is to take a multi-vitamin that has the proper balance of all the necessary nutrients your body needs. For a list of reputable top ranked vitamin and mineral supplements chosen in an independent supplement review, see Best Multivitamin Supplements. Many of these are manufactured to pharmaceutical or nutraceutical GMP compliance, which is the highest multivitamin standard possible. Keep in mind, however, that while mineral supplements are useful to plug nutritional gaps that are almost inevitable in modern diets, and to ensure we get optimal doses of nutrients, they are no substitute for a good diet. Instead, use them to complement a healthy diet and lifestyle. TOP Zinc RDA (Recommended Dietary Allowance) The Food & Nutrition Board of the Institute of Medicine, National Academy of Sciences, in their 1997-2001 collaboration between the US and Canada, set the daily Adequate Intake (AI) of Zinc as follows.
These dosages are the minimum required per day to ward off deficiency. In therapeutic use of this nutrient, dosage is increased as necessary for the ailment, keeping in mind Zinc toxicity levels. Legend 1 µg = 1 mcg = 1 microgram = 1/1,000,000 of a gram 1 mg = 1 milligram = 1/1,000 of a gram * Indicates AI figures based on Dietary Reference Intake (DRI) figures TOP Zinc Overdose Symptoms, Toxicity Level & Side Effects Zinc is considered safe and normally well-tolerated at recommended doses. However when taken in excess, symptoms of zinc overdose can include :
Zinc can also affect the status of other nutrients, the most important of which are copper and calcium. Even at normal levels, it can cause copper deficiency unless the diet includes copper-rich foods. High levels of zinc can also hinder absorption of calcium. People with kidney disease should lower their intake as they are at higher risk of zinc overdose, since excess is normally removed through urine. The Food and Nutrition Board of the Institute of Medicine has set Tolerable Upper Intake Levels (UL) for zinc. These are the levels above which there is risk of zinc side effects, especially when taken over a long time. Tolerable Upper Intake Levels (UL) for Zinc per Day
The ULs do not apply to the therapeutic use of zinc for medical treatment, which should be under medical supervision. Go to top of this page :: Zinc | Benefits | Deficiency Symptoms « Back to Health Supplements Nutritional Guide Home page |
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