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Zinc

Mineral: zinc Note zinc deficiency is common, but overdose is hazardous too.

Daily Value: 15 mg

Hazardous level: 50 mg daily safe for short term. "A UL of 40 milligrams for adults was set, based on studies showing that zinc adversely affects copper absorption at high levels of intake." 2005 US Dietary Reference Intakes

Average intake in US diet: 13.2 mg

Function: involved in many enzymes regulating metabolism and protein synthesis; aids in healing and immune function and in development of the reproductive system; sperm production

ZINC HAZARD: Science 303 (20 Feb 2004) STKE: "Excessive nitric oxide and the release of zinc from intracellular stores have been linked to neuronal death associated with stroke and some neurodegenerative diseases..."

SENIOR DOSAGE RATIONALE: Most elderly do not get enough zinc, but it may also be hazardous. Value is 18.5 mg - daily intake maximum + 8 mg to compensate for calcium interference

[Chevally, Osteo Int. 94: 245 - see 1996 AGE abstract 29 - people need 8-10 mg extra zinc per day, but there is no need for magnesium, current RDA is set too high]

KEY NOTES AND REFERENCES:

Whitney, E.N., and Rolfes, S.R. Understanding Nutrition, West Publishing, Minneapolis, 1993 pg 418 - Zinc - "Zinc supports the functions of numerous metalloenzymes involved in a multitude of metabolic processes. Zinc also assists in white blood cell immune function. " "Zinc can be toxic if enough is consumed. Zinc doses two or three times the RDA [which is 12-15 mg/day] lower the body's copper content"

Goldenberg, R.L., et al, "The effect of zinc supplementation on pregnancy outcome", JAMA 247: 463-8 (1995) 580 medically indigent but otherwise healthy African-American pregnant women given 25 mg zinc supplement in addition to multivitamin. "In all women, infants in the zinc supplement group had a significantly greater birth weight and head circumference" "Daily zinc supplementation in women with relatively low plasma zinc concentrations in early pregnancy is associated with greater infant birth weights and head circumferences" [comment from Council for Responsible Nutrition News"The researchers estimated that up to 58% of all low birth weights could potentially be avoided with the intake during the first trimester of pregnancy of a folic-acid containing daily multivitamin that also contains 15-20 mg of zinc"]

Wood, R.J., and Zheng, J.J., "High dietary calcium intakes reduce zinc absorption and balance in humans", Am J Clin Nutr. 65: 1803-9 (1997) quantitative report confirming that anyone taking calcium supplements should take an appropriate amount of zinc at the same time or risk zinc deficiency - I believe ours is the only product which has this proper formulation and ratio of zinc and calicum! "Our findings suggest that high-calcium diets [or supplements] can reduce net zinc absorption and balance and may increase the zinc requirement in adult humans." "Zinc deficiency has many untoward effects, including loss of appetite, growth retardation, skin changes, and immunologic abnormalities."

"An Antidote for the Common Cold?", Harvard Health Letter 22: 8 (Nov, 1996) "Although zinc appears to be safe for short-term use, long-term ingestion of large doses [found in many multivitamins, not ours] may cause imbalances in copper levels and could be toxic."

Prasad, A. "Clinical, biochemical, and nutritional spectrum of zinc deficiency in human subjects; an update", Nutr. Rev. 41: 197-208 (1983) "Growth retardation,... skin changes, poor appetite, mental lethargy, and delayed wound healing are some of the manifestations of chronically zinc-deficient human subjects...Zinc is involved in many biochemical reactions...zinc also may have a direct effect on free radicals."

Katz, E. and Margalith, E. "Inhibition of vaccinia virus maturation by zinc chloride", Antimicrob. Agents Chemother. 19: 213-17 (1981)

"Zinc ions have been previously shown to inhibit significantly the growth of rhino; picorna; and togaviruses... Zinc chloride reduces by more than 95% the infectious yield of vaccinia virus..."

Eby, G. A., Davis, D.R., and Halcomb, W. W. "Reduction in duration of common colds by zinc gluconate lozenges in a double-blind study", Antimicrob. Agents Chemother. 25:20-24 (1984) "One 23-mg zinc lozenge or matched placebo was dissolved in the mouth every 2 wakeful h after an initial double dose. After 7 days, 86% of 37 zinc-treated subjects were asymptomatic, compared with only 46% of 28...controls." "These results support the hypothesis that zinc-containing lozenges can effectively treat common colds, but the exploratory nature of this research requires that it be confirmed and investigated further..."

Hathcock, J. N. "Safety Limits for Nutrients", J. Nutr. 126: 2386S-89S(1996) "The RfD method uses a no observed adverse effect level or a lowest observed effect level [to determine the maximum safe dosage of nutrients established by the Environmental Protection Agency and utilized by the Food and Nutrition Board to set safe limits for nutrients.]" Table 1 shows the RfD [safe level of ingestion] of zinc is only 21 mg per day.

Williams, S. R., Nutrition and Diet Therapy, Mosby, St. Louis, 1993, pg. 712 "Chronic intakes of excess zinc, as little as 25 mg/day, can cause gastrointestinal distress, nausea, and impaired immune function."

WHITE PAPER REFERENCES FOR SENIOR FORMULATION

Rosenberg, IH and Solomons, NW, "Biological availability of minerals and trace elements: a nutritional overview", Am J Clin Nutr 35: 781-2 (1982) "diets consumed in the US do not provide recommended quantities of zinc. ...consumption of copper....is below the RDA...The average British diet provides about 60 mcg of selenium daily...

Bogden, JD, et al, "Zinc and immunocompetence in the elderly", Am J Clin Nutr 46: 101-9 (1987) "Zinc ingestion was below the RDA in more than 90% of study subjects" in 100 elderly ages 60-89

Hess, JW et al, "Zinc nutrition and cellular immunity in the elderly," J Am Ger Soc 35: 91 (1987) "16 of the 23 [elderly subjects] had zinc intakes less than 10 mg per day." "inadequate zinc nutrition may be a common problem in the elderly, affecting 30% or more of relatively healthy people" - 23 elderly, 16 of 23 had zinc intake of less than 10 mg/day - mean was less than 50% of RDA

Sandstead, HH, and Smith, J C Jr., "Deliberations and Evaluations of the approaches, endpoints, and paradigms for determining zinc dietary recommendations," J. Nutr 126: 2410S-18S (1996)

Table 3 median zinc intake

Age white Hispanic black

Male

60-69 11.52 8.71 8.77

70-79 10.34 8.13 7.84

80+ 9.06 7.74 7.04

female

60-69 7.71 6.80 6.93

70-79 7.18 6.42 6.37

80 6.59 5.26 5.92

"Usual dietary intakes of calcium do not impair zinc retention. On the other hand, effects of high intakes of calcium supplements...indicate pharmacological amounts of calcium can be detrimental" "many Americans are at risk of zinc deficiency" "the maximal safe dose of supplemental zinc is not known [but 50 mg/day was hazardous]" "For zinc supplements, the safe dose was 0.25 mg/kg/d" [equivalent to 19.25 mg for elderly men, 16.25 mg for elderly women]- median zinc intake- male 70-79 10.34; female 7.18; supplementation with 1800 mg calcium reduced zinc intake. Confirms hazardous level of 18.5 mg if 95% absorbed.

Whitney, E. N., et al, Nutrition for Health and Health Care, 1996, West Publ. Co.,, Mpls. pg 426 "Zinc deficiencies are common in older people. As many as 95% of older adults may not get the zinc they need, and many miss the mark by more than half."

Zhang, ZF, et al "Adenocarcinomas of the esophagus and gastric cardia: the role of diet", Nutr. Cancer 27: 298-309 (1997) "Decreased risk...was significantly associated with high ingestion of...niacin, vitamin B6, iron, and zinc. Higher intakes of vitamin A, beta-carotene, vitamin E, folate, phosphorus, and potassium were associated with a decreased risk..." - decreased risk of adenocarcinoma with higher intake of zinc, but not statistically significant

Pennington, J.A.T., Young, B.E., "Total Diet study nutritional elements, 1982-1989", J Am Diet Assoc 91: 179-83 (1991) - in national diet survey, zinc was low for older women

Bendich, A., Mallick, R., and Leader, S., "Potential Health Economic Benefits of Vitamin Supplementation", West J Med 166: 306-312 (1997) "Nearly $20 billion in hospital charges were potentially avoidable with daily use of folic acid and zinc-containing multivitamins by all women of childbearing age and daily vitamin E supplementation by those over 50."- 15-20 mg daily reduces low birth weight babies

Frishman, R., "Aging alters mineral needs", Harvard Health Letter 21: 6 (Apr 1996) "As scientists look more closely at aging, however, they've begun to suspect that the mineral requirements of a person who is 75 may not be the same as those of a 55-year old" "dietary recommendations for young and middle-aged adults - those for calcium, magnesium, and chromium-are not appropriate for older people" "recommended intakes of iron, zinc, copper, and selenium are probably just as appropriate for older as younger adults." "There is no evidence that older Americans are short on [magnesium], and there is scant reason for any healthyadult to take magnesium supplements." "[Chromium] is another nutrient that need not be purchased."- current RDA is appropriate for elderly; calcium may interfere with zinc, some advise taking 15 mg a day for men, 12 mg a day for women

Greger, JL, "Dietary intake and nutritional status in regard to zinc of institutionalized aged", J Gerontology 32: 549-553 (1977) "65 insitutionalized aged subjects. Dietary intake was generally adequate...except in regard to zinc and magnesium" "Dietary intake of protein, thiamin, riboflavin, niacin, vitamin A, ascorbic acid, calcium, and iron exceeded the RDA. The magnesium and especially the zinc content of the diets was below recommended levels"

Harvard Women's Health Watch 5 (Jan, 98), In "Zooming in on zinc", pg 6 "researchers found that in women and men who took a 600-mg calcium pill with a meal containing about 7 mg of zinc, zinc absorption was reduced by 50%. However, adding about 8 mg of zinc to the calcium supplement offset the decline." "Zinc supplements of 50 mg per day can cause a decrease in the important enzyme superoxide dismutase..Excessive intakesof zinc have also caused low levels of high-density lipoproteins, increasing the effects of low- density lipoproteins that in theory contribute to atherosclerosis and heart disease." The RDA is 12 mg, but most women get less than 10, with elderly getting about 9.

WHITE PAPER REFERENCES FOR STAY WELL FORMULATIONS

Bogden, JD, et al, "Zinc and immunocompetence in the elderly", Am J Clin Nutr 46: 101-9 (1987) "Zinc ingestion was below the RDA in more than 90% of study subjects" in 100 elderly ages 60-89. "The medical literature describes many possible mechanisms by which zinc may treat the common cold"

Mossad, SB, Macknin, ML, Medendorp, SV, and Mason, P., "Zinc Gluconate lozenges for treating the common cold: a randomized, double-blind, placebo-controlled study", Annals of Int Med 125: 81-88 (1996) 50 patients took zinc gluconate, 13.3 mg every 2 hrs, avg. 6x per day, during cold symptoms. "Zinc gluconate in the form and doage studied significantly reduced the duration of symptoms of the common cold...Individual patients must decide whether the possible beneficial effects...outweigh the possible adverse effects."

Gershwin, ME, Beach, R., and Hurley, L., "Trace metals, aging, and immunity", J. Am. Ger. Soc. 31: 374-8 (19??) "Zinc administration leads to a substantial amelioration of the immunodeficiency syndrome...The few studies conducted to date tend to indicate that adequate manganese nutriture is a prerequisite for normal antibody production...diets marginally deficient in copper resulted in a significantly impaired immune response. The importance of copper in the function of a wide range of cell types, including lymphocytes, macrophages, andneutrophils, has been demonstrated...Aberrant immune responses develop in animals deprived of dietary magnesium...Magnesium intake by elderly humans, like that of zinc,

has been reported to be far below RDA levels...Selenium deficiency...is associated with a depression of humoral immune responsiveness."

Meydani, S. at 1996 AGE meeting: selenium, zinc, and omega-3 fatty acids may be useful when ill - must be sodium selenite - 500 mg vitamin E makes immune system like young people, blocks cyclooxygenase type 2

Sandstead, HH, and Smith, J C Jr., "Deliberations and Evaluations of the approaches, endpoints, and paradigms for determining zinc dietary recommendations," J. Nutr 126: 2410S-18S (1996)

Table 3 median zinc intake for mature adults

"Usual dietary intakes of calcium do not impair zinc retention. On the other hand, effects of high intakes of calcium supplements...indicate pharmacological amounts of calcium can be detrimental" "many Americans are at risk of zinc deficiency" "the maximal safe dose of supplemental zinc is not known [but 50 mg/day was hazardous]" "For zinc supplements, the safe dose was 0.25 mg/kg/d" [equivalent to 19.25 mg for elderly men, 16.25 mg for elderly women] "A separate study found that supplementation with 50 mg zinc/d caused decreases in erythrocyte superoxide dismutase activity"

Margen, S. (Ed.), "Wellness made easy", UC Berkeley Wellness Newsletter 14: 8 (March, 1998) "Don't count on those popular zinc lozenges as a cold remedy. A recent analysis of six studies found that cold sufferers taking the lozenges were just as likely as those taking placebo pills to still have the cold after seven days."

"Zinc and the common cold: recent developments", Nutrition and the MD 23: 7-8 (1997) "Adults develop average of 2 to 4 colds and children an average of 6-to-8 coldseach year...zinc gluconate has been shown to reduce the symptoms of the common cold" "The rhinovirus contains numerous binding sites for zinc...As...serum and lymph concentration increase, zinc binds to HRV and blocks its ability to infect cells."

Walsh, CT, et al, "Zinc: health effects and research priorities for the 1990s", Environ Health Perspect 102 (suppl 2): 5-46 (1994) "Zinc is generally considered a relatively nontoxic metal...Zinc is required for the optimum function oof as many as 300 enzymes...In humans chronic, elevated intake of zinc, 100 mg or more per day prescribed or self-adminsitered, has been shown to induce copper deficiency" "Fischer et al studied the effects of a lower level of zinc supplementation (25 mg twice daily) on copper metabolism in 26 healthy adult men... Plasma zinc was significantly increased by week 2. No change occurred in plasma copper. However, by 6 weeks Cu,Zn-superoxide dismutase in red blood cells was decreased about 10%"