Have the ads for zinc supplements left out some vital information? Many do not list the ranges of safe supplementation as outlined by the Food and Drug Administration (FDA). The levels vary by sex, age and pregnancy. Many fail to point out that vegetarians need to take more zinc than others because of the lower rate of absorption that their diets afford them. Those over the age of 55 may experience greater occurrence of zinc deficiency.
An average adult needs about 15 milligrams (mg) per day of zinc. Zinc can become toxic for prolonged periods at levels over 150 mg per day. Supplementation used for specific conditions has an upper limit of 60 mg for men and 45 mg for women. The toxicity from zinc results from its competition with copper absorption and lower High Density Lipoprotein (HDL) levels.
Does the question of whether those cough drops with zinc added do any good recur with every cold season? If this question comes up again the answer is yes, they do appear to shorten the duration of the cold. You may receive the best benefits from the use of cough drops because the mouth mucosa is able to absorb the zinc ions from the slowly dissolved form more affectively.
Much of zinc's recent popularity can be traced to studies showing correlations from its immune system impact. When zinc levels are low; T-cells decrease. This result appears to be separate from its use in supplements aimed at fighting the common cold.
Zinc is found in every cell in the human body. It is necessary for the formation of DNA. Used in over 80 enzymes, zinc is stored in its largest amounts in the muscles. Zinc is found in shellfish, beef, egg yolk, pork, whole grains and nuts. Zinc found in plants is less available for use by humans. Oysters are especially high in zinc with 148 mg per 3.5 ounce serving. Additionally zinc assists the body's absorption of beta carotene.
With so many bodily functions depending on zinc it should come as no surprise that low serum levels of zinc are found in people suffering from a wide array of ailments. Among these are anorexia, slow wound healing, skin disorders and night blindness.
Zinc supplementation is used to treat those with recent burn injuries; those suffering from Crohn's disease; persons with high levels of alcohol consumption and as a treatment for Wilson's disease. Wilson's disease is genetically linked and causes brain damage without treatment. Zinc works by blocking copper absorption which in this case is a desirable outcome.
Alzheimer's disease seems to benefit from treatment with zinc. This may be because of the influence of enzymatic processes in DNA production in nerve cells. The levels of zinc in Alzheimer's patients are much lower than normal. Zinc deficiency could destroy nerve cells.
Zinc supplements should not be taken by persons with stomach or duodenal ulcers. Similarly, anyone taking tetracycline or prescription calcium should not take zinc supplements as they may interfere with the absorption of these drugs.