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For many of your body's needs, think zinc
Zinc's roles range from helping lemonade taste extra tart to RNA synthesis. Zinc helps regulate your cells, making it possible for them to grow, divide, and make proteins. Every single enzyme class has a member that requires zinc. The numbers are not in, but this could be well over 200 enzymes. This means that zinc helps many of the chemical reactions necessary for you stay healthy.
Quick Facts About Zinc
- RDA for adults is 15 mg a day or less, which most people can get easily from food.
- Far and away the best food source of zinc is oysters -- canned or smoked. Other zinc-rich foods include organ meats, lean beef, pork, turkey, lamb, herring, wheat germ and bran, legumes, and nuts.
- Signs of deficiency include slowed growth in children, slow wound healing, frequent infections, skin irritations, loss of taste and smell, low sperm count, and sterility.
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You May Need More Zinc if You Have (or Have Had)
- Chronic malnutrition
- Recent surgery
- A portion of your gastrointestinal tract surgically removed
- Recent severe burns or injuries
- A history of excessive alcohol or drug use
Or if You
- Are pregnant or breastfeeding
- Take oral contraceptives
- Are age 55 or older
- Take diuretics
- Eat a high-fiber diet
What Works Best -- and Worst -- with Zinc
- Zinc assists in absorption of vitamin A.
- It interferes with absorption of calcium, copper, iron.
- Diuretics increase zinc excretion.
- Oral contraceptives lower zinc blood levels.
- Take zinc with food to avoid stomach distress.
- For best absorption, don't take zinc with a high-fiber meal.
- If you take extra zinc, get some extra copper. The ratio should be 2 to 3 mg copper for every 15 mg zinc.
- Take tetracycline and zinc at least two hours apart.
Forms Available
- Most good multi supplements contain the RDA for zinc
- As part of a lozenge
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Chemical Forms
- Zinc sulfate
- Zinc acetate
- Zinc gluconate
- Zinc citrate
- Amino acid chelates of zinc
- Zinc picolinate
- Zinc aspartate
- Zinc orotate
Comments on Zinc
- When choosing your zinc supplement, consider how much zinc the tablet contains and how well your body can absorb it.
- Zinc sulfate may cause gastric irritation.
- Our bodies absorb the organic salts of zinc (zinc gluconate, zinc citrate, zinc aspartate, and zinc orotate) more easily than other forms of this mineral.
- Zinc picolinate may be better absorbed than zinc citrate or zinc gluconate.
- One study indicated that zinc citrate is best absorbed, then zinc gluconate, then zinc orotate, and lastly zinc sulfate.
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Known Benefits of Zinc
- Participates in DNA and RNA synthesis, thereby supporting cellular growth
- Essential for proper growth and development
- Participates in formation of sperm
- Needed for cellular division
- Helps maintain cellular structures
- Contributes to the normal function of hormones
Unproven Claims
- Boosts the immune system
- Protects against macular degeneration
- May prevent and shorten the duration of the common cold when used as zinc lozenges
Zinc May Prevent These Signs of Deficiency
- Stunted growth in children
- Skeletal abnormalities
- Collagen synthesis impairment
- Reduced taste and smell
- Hair loss
- Night blindness
- Impaired immune system
- Reduced protein synthesis
- Slowed wound healing
- Delayed sexual development in children
Recommended Dosage Range for Zinc
- Our pharmacists suggest that healthy adults may take 10 to 15 mg daily to supplement a well-balanced diet.
- RDA values were set as the minimum needed to offset deficiency or disease, not as an actual value needed for optimum health.
- In the United States, the average consumption of zinc is between 6 to 15 mg per day.
- Consult your physician before starting any high-dose supplement regimen.
Dietary Sources
Food Tips
Protein-rich foods are high in zinc, as are whole grains, legumes, and nuts.
| Foods High in Zinc | Serving Size | Amount of Zinc | Units |
|---|
Beef, ground
Beef liver
Chicken, without skin
Chickpeas
Lentils
Oysters, canned
Oysters, smoked
Wheat germ
White beans
|
3 ounces
3 ounces
3 ounces
1 cup
1 cup
3 ounces
3 ounces
1/4 cup
1 cup
|
4.6
5.2
2.1
2.5
2.5
77.3
103
3.6
2.5
|
mg
mg
mg
mg
mg
mg
mg
mg
mg
|
When and How to Take Zinc
Swallow tablets whole with a glass of water.
What to Take with Zinc
- Zinc aids the absorption of vitamin A.
- Take vitamin E in conjunction with zinc. A vitamin E deficiency may worsen the effects of zinc deficiency.
What Not to Take with Zinc
- Zinc should not be taken with meals since eggs, milk, and cereal (and possibly other foods) decrease your ability to absorb it.
- Calcium and iron may decrease zinc absorption.
- It is debatable whether copper and folic acid decrease zinc absorption.
- Phytates in plants with a phytate-to-zinc ratio greater than 10-to-1 may inhibit zinc absorption.
Storage
- Keep zinc in a cool, dry place away from direct sunlight and air.
- Don't store zinc in your bathroom medicine cabinet. Heat and moisture may make it less effective.
- Store safely out of children's reach.
Recommended Daily Allowance
| AGE/GROUP | RDA |
|---|
Infants
0 to 6 months
6 to 12 months
1 to 3 years
4 to 6 years
7 to 10 years
Males
11 to 14 years
15 to 18 years
19 to 24 years
25 to 50 years
51+ years
Females
11 to 14 years
15 to 18 years
19 to 24 years
25 to 50 years
51+ years
Pregnant
Lactating
1 to 6 months
6 to 12 months
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mg (milligrams)
5
5
10
10
10
15
15
15
15
15
12
12
12
12
12
15
19
16
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Warnings
Consult a physician before use or do not use zinc if:- You are about to start a high-dose supplement regimen
- You have a kidney impairment
Zinc May Have Interactions with
- Alcohol: regular consumption of alcohol reduces blood levels of zinc.
- Calcium: absorption is decreased.
- Copper: large doses of zinc increase the absorption of copper.
- Cortisone and cortisone-like drugs: may interfere with lab tests measuring zinc.
- Diuretics: increase the excretion of zinc which may require taking extra zinc.
- Iron: large doses of zinc increase the absorption of iron.
- Oral contraceptives: lower the blood levels of zinc.
- Penicillamine: can deplete the body of zinc.
- Quinolones (Cipro, Floxin, Maxaquin, Noroxin, Penetrex): are not absorbed well in the presence of calcium, iron, or zinc.
- Tetracycline: absorption of tetracycline is decreased.
- Vitamin A: zinc assists in the absorption of vitamin A.
Side Effects
- Zinc consumption at greater than 50 mg per day can block absorption of copper, causing a copper deficiency anemia, and elevate LDL cholesterol levels (the bad ones).
- Prolonged use of zinc with doses as low as 18.5 to 25 mg can lead to copper deficiency.
- Zinc is fairly well tolerated by the body.
Signs of Overdose
- Abdominal pain
- Bloody diarrhea
- Metallic taste in your mouth
- Nausea
- Vomiting
What to Do in Case of Overdose
Stop use and contact your physician immediately.
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Sources & Further Reading
Books
- 1. Dell, BL and Sunde, RA.Handbook of Nutritionally Essential Mineral Elements. Marcel Dekker, Inc. New York, NY 1997.
2. Fauci et al. Harrison's Principles of Internal Medicine, Fourteenth Ed. McGraw-Hill Co., Inc. 1998.
3. Groff, JL, Gropper, SS, Hunt, SM.Advanced Nutrition and Human Metabolism, Second Ed. West Pub. Co. St. Paul, MN 1995.
4. Kastrup EK et al. Drug Facts and Comparisons. Facts and Comparisons.
5. Meletis, CD and Jacobs, T.The Practitioner's Guide to Drug-Nutrient and Nutrient-Nutrient Interactions. 1996.
6. Werbach, MR.Nutritional Influences on Illness, Second Ed. Third Line Press. Tarzana, CA 1996.
Find more books on health and wellness at  barnesandnoble.com.
Articles
- 1. Birmingham CL, Goldner EM, Bakan R.Controlled trial of zinc supplementation in anorexia nervosa. Int J Eat Disord 1994 Apr;15(3):251-5.
- 2. Chausmer AB.Zinc, insulin and diabetes. J Am Coll Nutr 1998 Apr 17:2 109-15.
- 3. Choi DW, Koh JY.Zinc and brain injury. Annu Rev Neurosci 1998 21: 347-75.
- 4. Costello LC, Franklin RB.Novel role of zinc in the regulation of prostate citrate metabolism and its implications in prostate cancer. Prostate 1998 Jun 1;35(4):285-96.
- 5. Cuajungco MP, Lees GJ.Zinc metabolism in the brain: relevance to human neurodegenerative disorders. Neurobiol Dis 1997 4:3-4 137-69.
- 6. Cuajungco MP, Lees GJ.Zinc and Alzheimer's disease: is there a direct link?. Brain Res Brain Res Rev 1997 Apr 23:3 219-36.
- 7. Garland ML, Hagmeyer KO.The role of zinc lozenges in treatment of the common cold. Ann Pharmacother 1998 Jan 32:1 63-9.
- 8. Jackson JL, Peterson C, Lesho E.A meta-analysis of zinc salts lozenges and the common cold. Arch Intern Med 1997 Nov 10 157:20 2373-6.
- 9. Karcioglu ZA.Zinc in the eye. Surv Ophthalmol 1982 Sep-Oct;27(2):114-22.
- 10. Naveh Y, Schapira D, Ravel Y, Geller E, Scharf Y.Zinc metabolism in rheumatoid arthritis: plasma and urinary zinc and relationship to disease activity [see comments]. J Rheumatol 1997 Apr 24:4 643-6.
- 11. Pillay D, Gathiram P, Ubbink JB.Zinc status in vitamin B6 deficiency. Int J Vitam Nutr Res 1997 67:1 22-6.
- 12. Takeda A, Goto K, Okada S.Zinc depletion suppresses tumor growth in mice. Biol Trace Elem Res 1997 Winter;59(1-3):23-9.
- 13. Wissing U, Unosson M, Lennernas MA, Ek AC.Nutritional intake and physical activity in leg ulcer patients. J Adv Nurs 1997 Mar;25(3):571-8.
- 14. Wood RJ, Zheng JJ.High dietary calcium intakes reduce zinc absorption and balance in humans. Am J Clin Nutr 1997 Jun 65:6 1803-9.
- 15. Zaichick VYe, Sviridova TV, Zaichick SV.Zinc in the human prostate gland: normal, hyperplastic and cancerous. Int Urol Nephrol 1997 29:5 565-74.
- 16. Christian P, West KP Jr.Interactions between zinc and vitamin A: an update. Am J Clin Nutr 1998 Aug 68:2 Suppl 435S-441S.
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