Zinc
ZINC was was first recognized as an element in the early 1500's; but it was not found to be an important one until 1869, when it proved to be necessary for the growth of molds. By 1877, zinc had been isolated from the human liver. In 1934, scientists determined that it was an essential element for rats and mice; but it was not until 1974 that zinc was given a RDA. To date, researchers have found more than 200 zinc-dependent enzymes in the human body, which is more than all the other mineral-dependent enzymes combined. About 260 mg. of zinc is distributed throughout the adult body.
Zinc is a major mineral that supervises the efficiency and maintenance of carbohydrate and energy metabolism, protein synthesis and degradation, nucleic acid synthesis, acid-base balance, carbon dioxide transport, plus many other reactions including the formation of insulin. Because of its powerful antioxidant properties, zinc is sometimes referred to as "Vitamin E's neglected twin," especially in its ability to protect cells against free radicals. Zinc is important in the metabolism of Vitamin A and collagen, cellular immunity, maintenance of taste acuity, and the development of reproductive organs. Closely related to testosterone, zinc has helped increase potency.
Zinc also governs muscle contractions and increases mental alertness. Studies have proven its importance in brain function and in the treatment of schizophrenia. Known to speed healing, zinc has been used after surgeries and during bouts with ulcers as well as an antibiotic to clear acne.
Zinc is concentrated in the liver, kidneys, bones, retina, prostate, and muscles, but is mainly bound to albumin in the plasma. Its absorption is influenced by several factors, including the quantity in the diet; the presence of such interfering substances as phytates, calcium, fiber, and chelating agents; and by constant competition for absorption with copper and iron. The freely available zinc pool is small; thus, deficiecies can develop, despite total body zinc content. Small amounts of zinc are absorbed better than large amounts.
During stress, as much as 8000 mcg. can be lost in the urine every day. In addition, the prostate uses ten times more zinc than any other organ in the body. Zinc picolinate does naturally, and more cheaply, what drugs like Proscar try to do with chemicals, which is, block the body's production of dihydrotestosterone. With so many available ways to rob zinc, it is little wonder that American and Canadian men are leading the world in prostate disorders. Vitamin B6, taken with zinc for prostate enlargment, enables zinc to be better absorbed, but those taking large amounts of B6 require higher amounts of zinc. Although folic acid does interfere with zinc absorption, it does not block it entirely.
Zinc is known to boost the immune system in relation to the common cold. It is suspected that other disorders are also a result of a lack of this mineral. Low levels are found in people with depressed immune systems, including AIDS; and, since zinc is known to be important in the funtioning of insulin, diabetics often have low levels of zinc.
Galvanized containers have been known to leach zinc into food contents, causing toxicity symptoms to develop. Prolonged ingestion exceeding 15 mg./day has also brought on toxicities with symptoms of copper-deficient anemia, depressed white blood cells (WBC's), increased LDL ("bad" cholesterol), and decreased HDL ("good" cholesterol), along with decreased levels of serum ferritin and hematocrit.
Excessive amounts of zinc can also produce symptoms of a deficiency. Doses of 100 mg. or more daily can actually harm the immune system while lower doses enhance it. These amounts are not recommended since they can decrease copper levels which can lead to anemia and abnormal heart rhythms plus causing microcytosis (smaller RBC's) and neutropenia (fewer neutophillic WBC's). Research has also shown that mega doses have been linked to plaque formation in the brains of Alzheimer patients.
Deficiencies are the result of the removal of zinc during food processing. For example, two-thirds of zinc is lost during the refining of flour. Phosphorus-containing additives reduce absorption capabilities. In addition, EDTA, another food additive, traps metal impurities that migrate into foods, protecting the consumer in one way; but since zinc is a metal, it, too, is bound by EDTA, rendering it useless in the body. Foods grown in nutrient-deficient soil also contribute to a deficiency. By using tahini (ground sesame seeds) instead of butter on whole grain toast, zinc, calcium, and essential fatty acids, are provided.
Zinc Sulfate is most commonly used in research, but it is available by prescription and in over-the-counter supplements. Drug companies tend to favor this form.
Zinc Gluconate is preferred over the sulfate form by companies that sell supplements directly to the consumer. Scientific research shuns zinc gluconate because it is less concentrated than zinc sulfate, although, zinc gluconate used in lozenges has shown to speed recovery of the common cold.
Zinc Acetate is still in the research stage, but it is showing less gastrointestinal upset than zinc sulfate.
Chelated Zinc - Medical journals contain virtually no information about the safety of chelated zinc. Though gluconate or acetate forms have replaced zinc sulfate in a few studies, chelated zinc has not. As with all chelated minerals, the zinc form costs considerably more than zinc from other sources.
Zinc Pyrithione is also known as zinc pyridine or ZPT and is not for oral use. It is an antidandruff agent found in shampoos and conditioners. A few rare cases developed where ZPT caused the skin to become dry and irritated.
Summary:
Names: Zn and element 30. On commercial labels, it appears as zinc oxide or zince sulphate.
Deficiency symptoms include: retarded growth resulting in a short stature and hypogonadism (a decreased function of the gonads, the sex glands), slowed sexual develoment, testicular deterioration and dysfunction, sterility, decreased gonad function, deterioration of thymus gland, diminished sense of taste/smell, deterioration of protein formation, decreased appetite, deterioration of nutrient absorption, liver deterioration, internal inflammation, anemia, decreased development of bone/muscle/nervous system/hair, thinning hair, acne, skin lesions, white spots on nails, deformed nails, decreased immunity, decreased salivation, bad breath, loss of appetite, impaired wound healing, night blindness, photophobia, and behavioral changes.
Toxicity symptoms include: nausea, abdominal pain, fatigue, dizziness, dehydration, decreased levels of copper and iron, decreased muscle coordination.
Inhibitors include: corticosteroids, birth control pills, decreased phosphorus intake, antibiotics (especially tetracycline and relatives chlortetrocycline and oxytetracycline); and anticancer drugs. Such metal-binding drugs as Penicillamine, used to treat the copper accumulation of Wilson's disease, bind other metals, as well as zinc.
Helpers include: Vitamins A, C, E, calcium, copper, manganese, phosphorus, selenium, cysteine.
