Electronic letters to:

Practice:
Julie A. Irving, Andre Mattman, Gillian Lockitch, Kevin Farrell, and Louis D. Wadsworth
Element of caution: a case of reversible cytopenias associated with excessive zinc supplementation
CMAJ 2003; 169: 129-131 [Abstract] [Full text] [PDF]
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Electronic letters published:

[Read eLetter] Copper deficiency and anemia
David L. Watts   (12 August 2003)
[Read eLetter] Use the correct zinc supplement
David Potterton   (28 July 2003)

Copper deficiency and anemia 12 August 2003
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David L. Watts,
Consultant
Trace Elements, Inc.

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Re: Copper deficiency and anemia

dr.watts{at}traceelements.com David L. Watts

The fact that zinc intake can contribute to copper deficeincy and anemia is well known. However, any factor that contributes to copper deficency can potenially contribute to cytopenia. These include two of the most popular OTC vitamins taken by many individuals in the US and Canada, vitamin C and niacin. Even iron is antagonistic to copper and if taken over time can contribute to cytopenia.

Prolonged high intake of vitamins C and niacin, as well as the minerals zinc, iron, molybdenum and others, singularly or in combination can produce a copper deficiency, especially if an individuals copper status is marginal.

Therefore, evaluation of ones nutritonal status is recommended before and during instituting long-term dietary supplement intake. Hair mineral analysis has proven to be a good method of asessing nutritional copper status and its interrelationship with other elements.

Watts, David L. The Nutritonal Relationships of Copper. J. of Orthomol. Med. 4, 2, 1989.

Mason K.E. A Conspectus of Research on Copper Metabolism and Requirementsof Man. J.Nutr. 109, 1979.

Klvay, L.M. Hair as a Biopsy Material. II Assessment of Copper Nutriture. Am. J. Clin. Nutr. 23, 1970.

Use the correct zinc supplement 28 July 2003
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David Potterton,
Editor
British Naturopathic Journal

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Re: Use the correct zinc supplement

david.potterton{at}ntlworld.com David Potterton

Michael Leitzmann and colleagues have just reported in the Journal of the National Cancer Institute (July 2, 2003) that excessive zinc supplementation -- in excess of 100mg a day is associated with advanced prostate cancer, although there may be confounding factors. In the UK, the RDA is 15mg and this is effective for most of the indicated conditions if the correct zinc is used. There are a number of difference formulations available many with poor absorption levels and even poorer bioavailability (which is why research on zinc returns conflicting results). The least effective zinc formulations seem to be the ones that end up in multimineral tablets eg zinc sulphate. As a naturopath I would recommend using a formulation that includes copper eg zinc 15mg copper 1mg. Food state zinc/copper is probably the best currently available as this closely resembles the minerals as they are found in food. This also allows for long-term use. An exclusively zinc formulation ie zinc orotate (not including copper) should be used only in patients who are known to have high blood levels of copper.