Diagnose-Me: Treatment: Zinc

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	Zinc

Zinc
Recommended for…
Conditions prevented by it

Zinc is an essential trace mineral that occurs in greater amounts than any other trace mineral except iron. Its functions are varied and numerous, including synthesis of cholesterol, protein and fats, releasing vitamin A from the liver, assisting the immune system and cell growth, being required for vision, taste perception, prostrate reproductive health and insulin function, metabolizing alcohol, and protecting against copper and heavy metal toxicity such as cadmium and lead. Zinc is considered one of the more important "trace" minerals. By weight, zinc makes up 0.02% of the earth's crust and 0.003% of the human body (similar to iron).

Source

The best natural sources of zinc include: oysters, meats, wheat germ, hard cheeses, Swiss chard, lima beans, potatoes, oats, green leafy vegetables, pumpkin and squash seeds, soy beans/foods, tuna, kidney beans, ginger root, peas, leeks, lentils, cashews, sunflower seeds (and tahini), pecans, peanuts, filberts. Other sources include herring, poultry, eggs, buckwheat, brown rice, millet, corn, black-eyed peas, green beans, chickpeas, spinach, green onion, and sprouted grains.

Note: Food processing removes a large amount of zinc as well as other trace elements. For example, whole brown rice has more than 4 times the zinc that polished white rice has. Molasses has 42 times more zinc than an equal amount of white sugar. By weight, the germ part of wheat has 15 times more zinc than can be found in white flour.

Various forms of zinc exist, essentially in two forms: salt, and chelated. Salt forms of zinc include gluconate, citrate, picolinate and others. While various reports have touted the capabilities of certain salt forms to absorb better than others, proper chelated forms usually absorb better than salt forms. Supplements should take advantage of a combination of chelated and salt forms for maximum absorption.

Zinc gluconate is a popular form for the delivery of zinc as a dietary supplement. It is found naturally, and is also manufactured by the fermentation of glucose, typically by aspergillus niger, but also by other fungi. In its pure form, it is a white to off-white powder. It can also be manufactured by electrolytic oxidation, although this is a more expensive process.

Very often, zinc is included in prostate health, as well as BPH products.

Function; Reasons For Use

Zinc, in general, is considered an adjunct to the body's overall antioxidant system. For example, the important free-radical scavenging enzyme super-oxide dismutase (SOD) requires both zinc and copper for its activity.

Zinc plays a very important role in over 50 different proteins or enzymes in humans. These enzymes are critical for the immune system, overall cellular metabolism, control of protein synthesis and protection of membrane lipid peroxidation.

The popularity of zinc has increased recently as the use of zinc lozenges for colds have been researched and marketed. Zinc is also important for the proper health and function of the prostate.

Directions

The RDA for zinc 15mg; the optimal daily intake is 30-50mg; the average daily intake in the U.S. is 10mg per day. Therapeutic doses are 30-350mg but care must be taken to avoid toxicity.

Zinc absorption is enhanced by soy protein, red wine, glucose, and lactose.

Antagonists (things which impair assimilation or retention) include alcohol, chelating compounds, diuretics, oral contraceptives, penicillamine (causes zinc to be chelated and excreted along with intended heavy metals), prednisone/prednisolone: causes increased urinary excretion of zinc [Buist, 1984; 4 (3): p.114]

Copper, calcium, iron and phytates taken in large doses can interfere with (inhibit) zinc absorption and induce a deficiency, especially in pregnant women. People who take large doses of iron to correct anemia when they are already borderline zinc deficient can easily create a true zinc deficiency. Zinc should always be taken with copper in a 10 to 1 through 30 to 1 zinc to copper ratio.

One Suggested Supplemetation Regime
During any period of supplementation the zinc taste test should be repeated at appropriate intervals and the subsequent dose of zinc adjusted up to the required level. In addition, it should be noted that when starting any programme of zinc supplementation the starting dose should always be a minimum dose of 15-25mg. This is then increased slowly in the following manner stopping at the required level as demanded by the results of the taste test.

In the first week: take one 15-25mg dose per day.
Second week: two 15-25mg capsules or tablets per day.
Third week: one 50mg dose per day.
Fourth week: two 50mg doses per day.
Fifth and subsequent weeks: three 50mg doses per day.

The reason for this protracted introduction is that zinc treatment, in the presence of zinc deficiency, may initially induce a feeling of fatigue or depression: a slow introduction reduces this possibility. This initial paradoxical response (zinc is normally stimulant in its action - by improving vigor and vitality) is not inevitable but if it does occur it may discourage the user from continuing the treatment. Continued use, after two to three weeks, will normally result in the expected improvement in vitality. Tiredness persisting beyond this time suggests the need for additional oil supplements or the anti-oxidant vitamins or minerals.

Zinc should be taken each day after food. If unusual tiredness occurs during the initial stages of treatment it should be taken at night before retiring to bed. In this way it will benefit any difficulty in sleeping and promote increased vitality the following day. Various zinc preparations may be used including possibly chelated zinc, zinc citrate, zinc picolinate, or zinc gluconate. Zinc sulphate is the most common (and cheapest) presentation but should be avoided due to the frequent occurrence of gastric irritation and dyspepsia. To avoid such a possibility, as a precaution, any zinc preparation should be taken after food. The most efficiently absorbed is the chelated form. This is where the zinc is combined with an amino acid, which assists in its absorption.

High doses of zinc (50mg per day or more) should also be accompanied by a small dose of copper. This is because a large amount of zinc in the diet will compete with, and reduce the absorption of, copper. It therefore becomes necessary to take a regular supplement of copper to prevent a state of copper deficiency developing. The appropriate dose of copper is 2-4mg per day. This single dose is all that is required whatever the dose of zinc used.

High doses of zinc will also tend to reduce the absorption of iron. This is not usually a problem but, in strict vegetarians, when the intake of iron is low, there may be a need to take a small, regular dose of iron to prevent the occurrence of iron-deficiency anemia.

Side-Effects

It is wise to go above 15mg only with a doctor's supervision because long-term zinc supplementation may interfere with the absorption of copper, another essential trace mineral. Signs of toxicity include diarrhea, nausea and vomiting.

Zinc at doses of 20mg and above may cause stomach upset and/or nausea so it should always be taken with food. Long-term zinc supplementation above 50mg has been shown to decrease HDL cholesterol and increase total cholesterol. This may be due to an induced copper deficiency. In addition, copper deficiency anemia can occur as well. Large doses of zinc may also promote folate deficiency.

Zinc gluconate may interfere with the absorption of antibiotics, so combinations may be unsafe.