Trace element:Zinc

ZINC

DAILY REQUIREMENT OF ZINC
  • RDA for zinc in males and females are 11mg and 8mg.
  • RDA for Zinc during pregnancy is 11mg/d
  • Zinc recommendation for lactating women is 12mg/d.
  • The requirements for infants range between 3.5 - 5.0 mg/day.
  • RDA of zinc in a child is 6-8 mg/day
DISTRIBUTION OF ZINC IN THE BODY
  • Most zinc is in the brain, muscle, bones, kidney, and liver, with the highest concentrations in the prostate .
BIOLOGICAL FUNCTIONS OF ZINC:
  • Zinc has a role in regulation of binding of proteins to DNA.
  • Zinc is absolutely required for normal spermatogenesis, fetal growth, and embryonic development.
  • Insulin secretion is associated with Zinc.
  • Paneth cells are zinc-containing cells widely distributed in Lieberkuhn's crypts of intestine and play a role in mucosal immunity
  • Zinc containing enzymes are:
  1. Superoxide dismutase (it is a Cu-Zn protein complex)
  2. Carbonic anhydrase
  3. Leucine amino peptidase
  4. Carboxy peptides 'A'
  5. Alcohol dehydrogenase
  6. Retinine reductase
  7. Alkaline phosphatase
  8. Glutamate dehydrogenase
  9. Lactate dehydrogenase
  10. DNA and RNA polymerase
  11. d-ALA dehydratase
DEFICIENCY OF ZINC
  • Hypogonadism (sexual infantilism, loss of libido), poor weight gain (growth retardation) ,taste alteration,decreased immunity, hepatosplenomegly, hypochromic microcytic anemia, loss of hair,Dermatitis, Diarrhea,poor wound healing are seen in zinc deficiency.
  • The most frequent trace mineral deficiency developing in a patient receiving parenteral alimentation is a deficiency of Zinc.
  • Acrodermatitis enteropathica (AE):
  1. It is an autosomal recessive disorder of zinc absorption.
  2. It presents in infancy, characterized by a triad of acral dermatitis (face, hands, feet, anogenital area), alopecia, and diarrhea.
  3. Dose of zinc used in acrodermatitis enteropathica is 2-3 mg/kg body weight.
USES OF ZINC
  • Diarrhea:
  1. Zinc supplement given during an acute diarrhoea episode reduces severity and duration of disease.
  2. WHO and UNICEF recommend that children 6 months be given 20 mg daily.
  • Wilson's disease
  1. Nontoxic
  2. Produces a negative copper balance by blocking intestinal absorption of copper
  3. It induces hepatic metallothionein synthesis, which sequesters additional toxic copper
ZINC POISONING
  • Metal fume fever is common in chronic poisoning with Zinc.
  • Zinc poisoning is likely in a person presenting with rigors and chills and a clinical picture resembling malaria.
Exam Question
  • A highest level of zinc is found in Prostate.
  • Daily requirement of zinc in humans is 9.4 mg/day.
  • Dose of zinc used in acrodermatitis enteropathica is 2-3 mg/kg body weight.
  • Zinc is an essential component of several enzymes like carbonic anhydrase, alcohol dehydrogenase, alkaline phosphatase, carboxypeptidase and superoxide dismutase.
  • Acrodermatitis enteropathica is an autosomal recessive disorder of zinc absorption.
  • Advantages of Zinc therapy for Wilson disease are as follows: Produces negative copper balance ,Blocks intestinal absorption of copper , Induces hepatic metallothionein synthesis.
  • Micronutrient associated with rash and diarrhea is Zinc.
  • Dose of zinc recommended for 9 month old during acute diarrhoea is 20 mg daily.
  • Zinc has a role in regulation of binding of proteins to DNA.
  • Zinc is absolutely required for normal spermatogenesis, fetal growth, and embryonic development.
  • Daily requirement of Zinc for adult men is 9.4mg/d and for women is 6.8mg/d.
  • Paneth cells contain Zinc.
  • Metal fume fever is common in chronic poisoning with Zinc.
  • Zinc poisoning is likely in a person presenting with rigors and chills and a clinical picture resembling malaria.
  • Hypogonadism (sexual infantilism, loss of libido), poor weight gain (growth retardation) ,taste alteration,decreased immunity, hepatosplenomegly, hypochromic microcytic anemia, loss of hair,Dermatitis, Diarrhea,poor wound healing are seen in zinc deficiency.
  • Zinc supplement given in 12 month baby is 3.5-5 mg/day.
  • RDA of zinc in a child is 6-8 mg /day.
Don't Forget to Solve all the previous Year Question asked on Trace element:Zinc