Det står store konsentrasjoner....og da antar jeg at det er snakk om betydelig mer enn en tablett hver morgen
Ja. Det finnes såvidt jeg kan se ingen solid dokumentasjon på at det å spise 50 gram zink sulfate eller 30 mgram zink citrate er farlig for helsa. Man skal utfra det vi vet i dag spise
veldig mye over anbefalte doser før kolesterol-nivået blir signifikant høyere og at immunforsvaret svikter. Husk også at de som trener trenger noe mer zink enn en som ikke trener.
Her er WHOs oppsummering av evt. helsefarer ved zink-inntak:
"Acute toxicity arises from the ingestion of excessive amounts of zinc salts, either accidentally or deliberately as an emetic or dietary supplement. Vomiting usually occurs after the consumption of
more than 500 mg of zinc sulfate.
Manifest copper deficiency, which is the major consequence of the chronic ingestion of zinc (13), has been caused by
zinc therapy (150–405 mg/day) for coeliac disease, sickle cell anaemia, and acrodermatitis enteropathica (28–30). Zinc supplementation of healthy adults with
20 times the recommended dietary allowance for 6 weeks resulted in the impairment of various immune responses (32). Gastric erosion is another reported complication of a daily dosage of
440 mg of zinc sulfate (1). Daily supplements of
80–150 mg of zinc caused a decline in high-density lipoprotein cholesterol levels in serum after several weeks (1), but this effect was not found in some other studies. In an Australian study, no detrimental effect of 150 mg of zinc per day on plasma copper levels was seen in healthy volunteers over a period of 6 weeks (33). In a small-scale study on zinc-refinery workers, no evidence was found of increased mortality from any type of cancer (1). In subjects with low baseline levels of serum zinc, no significant difference in the risk of death from cancer or cardiovascular diseases, as compared with those with high baseline levels, was observed (34).
7. Conclusions
In 1982, JECFA proposed a daily dietary requirement of zinc of 0.3 mg/kg of body weight and a provisional
maximum tolerable daily intake (PMTDI) of 1.0 mg/kg of body weight (35). The daily requirement for adult humans is 15–22 mg/day.
References
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21. Waalkes MP et al. Protective effects of zinc acetate toward the toxicity of nickelous acetate in rats. Toxicology, 1985, 34:29-41.
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23. Rath FW et al. Zur Wirkung oral applizierten Zink auf die Metastasenbildung nach intravenoser Applikation von Zellen eines benzpyreninduzierten Rattensarkoms. [Effect of the oral administration of zinc on metastasis after intravenous application of benzpyrene-induced rat sarcoma.] Acta histochemica, 1990, 39(Suppl.):201-203.
24. Chen XC et al. Low levels of zinc in hair and blood, pica, anorexia and poor growth in Chinese preschool children. American journal of clinical nutrition, 1985, 42:694-700.
25. Smith RM et al. Growth-retarded aboriginal children with low plasma zinc levels do not show a growth response to supplementary zinc. Lancet, 1985, i(8434):923-924 (letter).
26. Cavdar AO et al. Zinc deficiency in geophagia in Turkish children and response to treatment with zinc sulfate. Haematologica, 1980, 65:403-408.
27. Jackson MJ et al. Stable isotope metabolic studies of zinc nutrition in slum-dwelling lactating women in the Amazon valley. British journal of nutrition, 1988, 59:193-203.
28. Porter KG et al. Anemia and low serum-copper during zinc therapy. Lancet, 1977, ii(8041):774 (letter).
29. Prasad AS et al. Hypocupremia induced by zinc therapy in adults. Journal of the American Medical Association, 1987, 240:2166-2168.
30. Hoogenraad TU, Dekker AW, van den Hamer CJA. Copper responsive anaemia, induced by oral zinc therapy in a patient with acrodermatitis enteropathica. Science of the total environment, 1985, 42:37-43.
31. Festa MD et al. Effect of zinc intake on copper excretion and retention in man. American journal of clinical nutrition, 1985, 41:285-292.
32. Chandra RK. Excessive intake of zinc impairs immune responses. Journal of the American Medical Association, 1984, 252:1443-1446.
33. Samman S, Roberts DCK. The effect of zinc supplements on plasma zinc and copper levels and the reported symptoms in healthy volunteers. Medical journal of Australia, 1987, 146:246-249.
34. Kok FJ et al. Serum copper and zinc and the risk of death from cancer and cardiovascular disease. American journal of epidemiology, 1988, 128:352-359.
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