Thursday, July 25, 2013

What Do Those Nutrients Do? Zinc

Zinc is a trace mineral. That means that your dog’s body needs relatively small amount of zinc. But just because not a lot is needed, doesn’t make this nutrient any less important. It is an essential mineral, which means it needs to be supplied in the diet.

Animal tissues are rich source of zinc. Veal liver has the most zinc.

Small quantities of zinc are found in most tissues.

Does your dog have a dry, harsh coat with fading color? Skin lesions?  A poorly functioning immune system? Poor wound healing? Poor appetite or digestive disturbances? Could zinc have something to do with it?

In dogs, a zinc deficiency will show in the skin and coat first.

Zinc has a number of critical functions. It is used by more than 300 enzymes to assist growth, healing, reproduction, protein and carbohydrate metabolism.

What does that mean?

Simply put, enzymes are functional proteins that are responsible for speeding up biochemical reactions. If that doesn’t really sound important, consider this: digesting a chunk of beef, without enzymes, would take about 40 years! It would happen without enzymes, eventually, but none of us would live that long. Practically there would not be life without enzymes.

Some enzymes take things apart, such as digesting food, other enzymes put new things together. Enzymes are like worker bees. They do everything.

What does zinc have to do with it?

In order to function, many enzymes need what is called a cofactor. If an enzyme was a power drill, the cofactor would be the drill bit. In other words, without zinc, over 300 enzymes cannot do their jobs. Zinc deficiency is like having a big factory, with all the materials and workers in place, but without their tools..

A cofactor can be a metal ion (iron, copper, magnesium, manganese, zinc, calcium, or cobalt)
or a complex organic molecule known as a coenzyme.Image Midlands Tech

Without zinc, carbohydrates and proteins cannot be metabolized, new proteins cannot be made. 

Cells cannot replicate, wounds cannot heal, and the immune system is compromised. Many types of immune cells seem to depend on zinc to function optimally. Zinc also has antimicrobial actions because it competes with other ions essential  the metabolism of the germs.

Beside all that, zinc also has a structural role. 

It is crucial in the structure and function of cell membranes. For example, with insufficient zinc, cell membranes become more vulnerable to oxidative stress.

Yes, zinc is also an antioxidant. It protects proteins and enzymes from free radicals.

Zinc is also important in the regulation of genetic activities, cell signaling, hormone release and nerve impulse transmission.

For example, zinc plays a key role in the synthesis and action of insulin. It may also affect the release of insulin, glucose tolerance and insulin resistance. Furthermore, diabetes leads to important losses of zinc from the body.

Zinc is also necessary for adrenal gland and liver function and is even involved with the sense of taste and smell.

Zinc is synergistic with copper; zinc deficiency contributes to excessive accumulation of copper in tissues. Conversely, too much zinc affects copper absorption.

Zinc interacts with iron and calcium. Diets too high in these minerals can impair the absorption of zinc. Zinc is also essential for vitamin A mobilization and transportation from the liver.

The mineral is also a mercury antagonist and prevents cadmium toxicity. Pretty cool, isn’t it?

Animal proteins are high in zinc and low in copper, while the reverse is true for plant-based proteins.

A reversed ratio of zinc and copper contributes to inflammation and thyroid and adrenal issues. Further, phytates, present in plants, particularly grains, interfere with zinc uptake. Stress also contributes to zinc losses from tissues.

As important as zinc is, too much zinc (often caused by the ingestion of pennies or galvanized metal) causes hemolytic anemia. Zinc is absorbed into the bloodstream where it is bound to proteins and damages red blood cells (the exact mechanism of action is still unclear). When severe enough, hemolytic anemia can lead to multiple organ failure and death.

Further reading:

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  1. What an informative post. Now I am off to read some of the other posts in this series. Thank you.

    1. Thank you :-) Working on eventually covering all nutrients.