Copper bioavailability and requirements

Sandstead, Harold H.

doi:10.1093/ajcn/35.4.809

Cited by 101 publications

(20 citation statements)

References 38 publications

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“…Whether enzyme levels were altered in other tissues was not tested, although studies with rats by the same group (189) have shown decreases in liver superoxide dismutase as zinc intake increased. Balance studies in humans also suggest that copper requirements for equilibrium are increased as dietary zinc is elevated (217) In summary, several studies indicate that zinc may reduce the activity of erythrocyte superoxide dismutase, probably in response to a change in copper status. The physiological significance of this effect has not been established, either in primary copper deficiency or secondary to elevated zinc levels.…”

Section: Interactions With Other Metalsmentioning

confidence: 97%

Zinc: Health Effects and Research Priorities for the 1990s

Walsh¹,

Sandstead²,

Prasad³

et al. 1994

Environmental Health Perspectives

156

225

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This review critically summarizes the literature on the spectrum of health effects of zinc status, ranging from symptoms of zinc deficiency to excess exposure. Studies on zinc intake are reviewed in relation to optimum requirements as a function of age and sex. Current knowledge on the biochemical properties of zinc which are critical to the essential role of this metal in biological systems is summarized. Dietary and physiological factors influencing the bioavailability and utilization of zinc are considered with special attention to interactions with iron and copper status. The effects of zinc deficiency and toxicity are reviewed with respect to specific organs, immunological and reproductive function, and genotoxicity and carcinogenicity. Finally, key questions are identified where research is needed, such as the risks to human health of altered environmental distribution of zinc, assessment of zinc status in humans, effects of zinc status in relation to other essential metals on immune function, reproduction, neurological function, and the cardiovascular system, and mechanistic studies to further elucidate the biological effects of zinc at the molecular level. - There is considerable evidence that zinc deficiency in humans is a serious worldwide problem and outweighs the potential problem of accidental, self-imposed, or environmental exposure to zinc excess. Acute deficiency (1) and chronic deficiency (2) are well-known entities in human populations and are probably much more common than generally recognized. The importance of zinc for human health was first documented in 1963 (3) Telephone (617) (617) 638-4329. E-mail: ctwalsh~bu.edu renal disease, and other chronically debilitating diseases are now known to be predisposing factors for zinc deficiency in humans (4).Zinc deficiency is reflected in clinical syndromes which affect men and women of all ages and all socioeconomic and cultural classes in the United States. It is neither prevalent in any specific area of the United States nor associated with any specific or definitive biochemical marker, which can make its identification difficult and confusing. Its presence is manifested by a wide spectrum of symptoms, from acute, life threatening problems to mild subclinical or marginal disorders which may only vaguely disturb well being. The acute problems are often seen in profoundly ill patients treated in hospitals, whereas subclinical problems may be so vague that patients seek assistance outside traditional medical practice.Based upon clinical data and using traditional, epidemiologic techniques, Henkin and Aamodt (5) have reclassified zinc deficiency into three syndromes; these are a) acute, b) chronic, and c) subacute zinc deficiency. Acute zinc deficiency is relatively uncommon and follows parenteral hyperalimentation or oral L-histidine administration. Chronic zinc deficiency is more common, usually resulting from chronic dietary lack of zinc. Subacute or latent zinc deficiency is the most common of these syndromes. It is estimated that there are 4...

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Section: Interactions With Other Metalsmentioning

confidence: 97%

Zinc: Health Effects and Research Priorities for the 1990s

Walsh¹,

Sandstead²,

Prasad³

et al. 1994

Environmental Health Perspectives

156

225

View full text Add to dashboard Cite

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“…Total losses of copper of 400-500 µg/day, consisting of losses via the skin (50-100 µg/day), urinary losses (25-50 µg/day) and faecal losses (300-400 µg/day) were assumed. The AR was considered to fall within a range of 1.35-1.65 mg/day, taking into account 30 % absorption (Sandstead, 1982). A PRI of 2 mg/day for men and 1.5 mg/day for women was set.…”

Section: Adultsmentioning

confidence: 99%

Scientific Opinion on Dietary Reference Values for copper

Products¹

2015

EFSA Journal

138

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Following a request from the European Commission, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) derived Dietary Reference Values (DRVs) for copper. Owing to the absence of appropriate biomarkers of copper status and the limitations of available balance studies, the Panel was unable to derive Average Requirements (ARs) and Population Reference Intakes (PRIs). Hence, Adequate Intakes (AIs) were defined based on mean observed intakes in several European Union (EU) countries, given that there is no evidence of overt copper deficiency in the European population. Data from balance studies were used as supportive evidence. For adults, AIs of 1.6 mg/day for men and 1.3 mg/day for women are proposed. For children, AIs are 0.7 mg/day for children aged 1 to < 3 years, 1 mg/day for children aged 3 to < 10 years, and 1.3 and 1.1 mg/day for boys and girls aged 10 to < 18 years, respectively. For infants aged 7-11 months, based on mean observed intakes in four EU countries, an AI of 0.4 mg/day is proposed, which is supported by upwards extrapolation of estimated copper intake in exclusively breast-fed infants. For pregnant women, an increment of 0.2 mg/day is estimated to cover the amount of copper deposited in the fetus and the placenta over the course of pregnancy and in anticipation of the needs for lactation, and for lactating women the same increment is estimated to cover the amount of copper secreted with breast milk. Thus, for pregnant and lactating women, the Panel derived an AI of 1.5 mg/day. Copper is an essential micronutrient required for electron transfer processes. It is a central component of many enzymes, including those involved in neurotransmitter synthesis, in energy metabolism and in collagen and elastin cross-linking.The main food group contributing to the copper intake of all population groups except infants is grains and grain-based products. Another important contributor to copper intake is the food group meat and meat products.Based on balance studies and other studies, the Panel considered that copper absorption from the diet is around 50 % for all age and life-stage groups.The primary site of copper absorption is the upper small intestine. Uptake is through a carrier protein, Ctr1, and once in the cell, the copper is directed towards its target via one of a series of chaperone proteins that ensure the metal is present in a non-toxic form. In the gut, the major pathway of transport into the portal circulation is via a Cu-ATPase, ATP7A. In the portal circulation, copper is bound to histidine, albumin or possibly transcuprein and transported to the liver, where it is incorporated into ceruloplasmin, which is then secreted into the systemic circulation. It is taken up into the liver through Ctr1 and, if it is not incorporated into ceruloplasmin, it is stored as metallothionein. Excess copper is excreted in bile after transport across the apical membrane of the hepatocytes via another ATPase, ATP7B. This copper is not reabsorbed. In humans, between 80 and 95 % of the copper in...

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“…Esse resultado mostra que não houve interação entre zinco, cobre e ferro, situação na qual teria ocorrido anemia por alta ingestão de zinco, ou seja, alta ingestão de zinco dietético levando à deficiência de cobre por competição pelos sítios de ligação da metalotioneína nas células mucosas intestinais 43 , que por sua vez restringe a utilização de ferro. A ceruloplasmina, proteína cobre dependente, é essencial para a mobilização de ferro a partir dos depósitos, antes de sua incorporação na hemoglobina 44 .…”

Section: Discussionunclassified

Estado nutricional, ferro, cobre e zinco em escolares de favelas da cidade de São Paulo

Santos¹,

Amâncio²,

Oliva³

2007

Rev. Assoc. Med. Bras.

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INTRODUÇÃOSegundo dados da Organização Mundial de Saúde (OMS), a prevalência de comprometimento grave do crescimento em países em desenvolvimento tem diminuído progressivamente de 47% em 1980 para 33% em 2000. Cerca de um terço de todas as crianças com idade inferior a 5 anos apresentam comprometimento grave do crescimento, sendo que 70% vivem na Ásia, 26% na África e 4% na América Latina e Caribe 1 . O "stunting" nutricional na infância, um indicador de desnutrição crônica, tem sido sugerido como um fator que contribui para altas taxas de obesidade em adolescentes e adultos de países em desenvolvimento 2 . A comparação de estudos realizados nos períodos de 1974/ 75 e 1995/96 sobre a prevalência de desnutrição e obesidade em crianças e adolescentes, mostra que em nosso país a desnutrição diminuiu de 14,8% para 8,6%, sendo que a obesidade aumentou de 4,1% para 13,9%3 . Assim, a progressão da transição nutricional caracterizada por redução na prevalência dos déficits nutricionais e a ocorrência mais expressiva de sobrepeso e obesidade têm sido observadas em sociedades em desenvolvimento que experimentam rápidas e intensas transformações de crescimento econômico e de estrutura demográfica 4 . EST RESULTADOS.Foram maiores o peso corporal, circunferência do braço, dobras cutâneas do tríceps e subescapular, resistência elétrica, escores Z da área do braço, área muscular do braço e percentual de gordura corporal no sexo feminino em relação ao masculino. Baixa estatura foi encontrada em 8% das meninas e 5,6% dos meninos, sem diferença quanto ao gênero. Houve menor prevalência de desnutrição (2% das meninas e 5,6% nos meninos), do que de sobrepeso e obesidade (30% e 11,2%, respectivamente). Observou-se anemia em 24,4% e ferropenia em 10,5% dos escolares com ou sem anemia. Apresentaram valores abaixo do limite inferior do padrão de referência para cobre e zinco séricos, respectivamente três e sete indivíduos. CONCLUSÃO. Na população estudada, de baixo nível econômico e institucionalizada, ocorre o processo de transição nutricional e alta prevalência de anemia que não resulta da interação ferro, cobre e zinco.UNITERMOS: Estado nutricional. Composição corporal. Ferro. Cobre. Zinco.O uso de índices antropométricos tem sido uma estratégia válida para gerar indicadores sensíveis do estado nutricional, tendo como objetivo determinar a massa corporal, expressa pelo peso; as dimensões lineares, especialmente a estatura; e a composição corporal (a gordura subcutânea e a massa muscular). Seus resultados podem refletir, também, a condição de vida dos grupos populacionais estudados 5 . Além do déficit pôndero-estatural e da vulnerabilidade às doenças infecto-parasitárias, a desnutrição, quer por insuficiência quer por excesso, se correlaciona com outras carências nutricionais como de micronutrientes.A anemia por deficiência de ferro é atualmente o problema nutricional mais prevalente, afetando cerca de 1,3 bilhão de pessoas, com aumento da sua prevalência e morbidade em crianças e adolescentes do sexo feminino 6 . Diferencia-se de o...

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Copper bioavailability and requirements

Cited by 101 publications

References 38 publications

Zinc: Health Effects and Research Priorities for the 1990s

Zinc: Health Effects and Research Priorities for the 1990s

Scientific Opinion on Dietary Reference Values for copper

Estado nutricional, ferro, cobre e zinco em escolares de favelas da cidade de São Paulo

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