What is the Role of Zinc in Good Nutrition?




Key Functions of Zinc

Best sources of Zinc

Who would benefit from Zinc supplementation?

When to use Zinc supplementation

How much Zinc is usually taken?

What are the side effects of using Zinc?



Zinc is vital for many biological functions such as disease resistance, wound healing, digestion, reproduction, physical growth, diabetes control, taste and smell. It is therefore essential for human health.


Every cell in the human body requires zinc to multiply and more than 300 enzymes need zinc for proper functioning.


High-zinc foods plays the following role in your family’s diet:

  • Help balance blood sugar
  • Stabilize your metabolic rate
  • Prevent a weakened immune system
  • Support an optimal sense of smell and taste

If you or anyone in your family experience any of the following symptoms then you might need

Zinc supplementation :

  • Impaired sense of taste or smell
  • Lack of appetite
  • Depression
  • Growth failure in children
  • Frequent colds and infections

Remember to always first consult with your medical practitioner before taking supplements.



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Key Functions of Zinc


Supplementation with zinc, or zinc and iron together, has been found to improve vitamin A status among children at high risk for deficiency of the three nutrients.


Although zinc is associated with potential detrimental effects on copper and calcium absorption, it is also supportive of other nutrients. For instance, without zinc, vitamin A cannot be effectively transported around the body, and cannot efficiently be mobilized when it is needed.


Zinc has essentially four important functions in the body, namely:


  1. Regulating genetic activitiesZinc is an important regulator of many genetic activities. Zinc is essential for reading genetic instructions, and when diets do not contain foods rich in zinc, the gene transcription fails.

  2. Supporting blood sugar balance and metabolic rate Insulin is required to move sugar from our bloodstream into our cells leading to what we call - insulin response. Without enough zinc in our food the insulin response decreases, and our blood sugar becomes difficult to stabilize. Also, the rate at which our body create and use up energy (Metabolic rate) - also depends on zinc for its regulation. When it is deficient in the diet, metabolic rate drops along with hormonal output by our thyroid gland.

  3. Supporting smell and taste sensitivityGustin is a small protein that is directly involved in our sense of taste. For our sense of taste to function properly Zinc must be linked to gustin. An impaired sense of taste and smell are therefore common symptoms of zinc deficiency.

  4. Supporting immune functionIn children, researchers have studied the effects of zinc deficiency and supplementation on immune response and number of white blood cells. In these studies, zinc deficiency has been shown to compromise white blood cells numbers and immune response, while zinc supplementation has been shown to restore conditions to normal.


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Best sources of Zinc


The best sources of zinc include: calf's liver, mushrooms and spinach.

Other Good sources of zinc include oysters, meat, eggs, seafood, black-eyed peas, tofu, and wheat germ.


mushroomspinachoysters
MushroomSpinachOysters
Meateggs
MeatEggs



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Who would benefit from Zinc supplementation?


The effects of zinc deficiency for any member of your family may be severe, ranging from impaired neuropsychological functions, growth retardation and stunting, impaired reproduction, immune disorders, dermatitis, impaired wound healing, lethargy, loss of appetite and loss of hair.


A "World Health Report 2002" by the WHO estimated that one-third (33%) of the world's population is at risk of inadequate zinc intakes.


The reason being that Zinc deficiency in agricultural soils is also a major worldwide problem. It not only affects crop yield but also the quality.


Severe soil zinc deficiency can cause complete crop failure whilst losses of up to 30% can occur in yield of cereal grains in crops such as wheat, rice and maize as a result of even mild deficiencies.


Zinc deficiencies are quite common in people living in poor countries. Phytate, a substance found in pita, matzos, and some crackers significantly reduces absorption of zinc thereby increasing the chance of zinc deficiency.


Low-income pregnant women and pregnant teenagers are at risk for marginal zinc deficiencies. Supplementing with 25–30 mg per day will be beneficial and should improves pregnancy outcome in these groups.


People with liver cirrhosis appear to be commonly deficient in zinc.


People with Down’s syndrome are also commonly deficient in zinc. Though optimal intake of zinc for people with Down’s syndrome remains unclear it was found that giving zinc supplements to children with Down’s syndrome has been reported to improve impaired immunity and thyroid function.


Children with “patchy areas of hair loss” have been reported to be deficient in zinc.


Zinc deficiencies are more common in alcoholics and people with sickle cell anemia, malabsorption problems, and chronic kidney disease.



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When to use Zinc supplementation


Zinc may play a role in the prevention and/or treatment of the following health conditions:

  • Acne
  • Alcoholism
  • Alopecia
  • Alzheimer's disease
  • Anorexia nervosa
  • Atopic dermatitis
  • Benign prostatic hypertrophy
  • Cervical dysplasia
  • Common cold
  • Crohn's disease
  • Diabetes
  • Epilepsy
  • Graves' disease
  • Herpes simplex
  • HIV/AIDS
  • Infertility (male)
  • Inflammatory bowel diseases
  • Influenza
  • Macular degeneration
  • Osteoarthritis
  • PMS
  • Psoriasis
  • Rheumatoid arthritis
  • Seborrheic dermatitis
  • Senile cataracts


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How much Zinc is usually taken?


Moderate intake of zinc, approximately 15 mg daily, is adequate to prevent deficiencies.


Higher levels up to 50 mg taken three times per day, are reserved for people with certain health conditions, under the supervision of a doctor.


For the alleviation of cold symptoms, lozenges providing 13 - 25 mg of zinc in the form zinc gluconate, zinc gluconate-glycine, or zinc acetate are generally used frequently but only for several days.



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What are the side effects of using Zinc?


Zinc intake in excess of 300 mg per day has been reported to impair immune function.


Some people report that zinc lozenges lead to stomach ache, nausea, mouth irritation, and a bad taste.


Zinc inhibits copper absorption. Copper deficiency can result in anemia, lower levels of HDL (“good”) cholesterol, or cardiac arrhythmias. Copper intake should be increased if zinc supplementation continues for more than a few days (except for people with Wilson’s disease). Most sources recommend a 10:1 ratio of zinc to copper. However, evidence suggests that no more that 2 mg of copper per day is needed to prevent zinc-induced copper deficiency.


Many zinc supplements include copper in the formulation to prevent zinc-induced copper deficiency. Zinc-induced copper deficiency has been reported to cause reversible anemia and suppression of bone marrow.


Zinc competes for absorption with copper, iron, calcium, and magnesium. A good multi-mineral supplement will help prevent mineral imbalances that can result from taking high amounts of zinc for extended periods of time.



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