Zinc

Question 1

<p>Zinc</p>

Answer 1

<p>• Zn is a cofactor in over 200 hundred metalloenzymes involved in catalytic, structural and regulatory functions; such as:<br></br>- Superoxide Dismutase (SOD) antioxidant.<br></br>- Alcohol Dehydrogenase breakdown of alcohol (↑ alcohol intake = ↑ zinc demand).<br></br>- Carboxypeptidase digestion of proteins.<br></br>- Other enzymes involved in Haem synthesis, folate absorption and DNA/RNA synthesis.<br></br>• Zinc is the most abundant intracellular trace element (the body contains 2g of Zn).</p>

Question 2

<p>Zinc: Food Sources</p>

Answer 2

<p>• The highest food source of Zinc is oysters. With seeds, nuts, whole<br></br>grains, meat and other shellfish also containing good amounts.<br></br>• Vegetables vary in Zn content depending on the soil quality</p>

<p>Oysters 33.24mg</p>

<p>Sesame 10.25mg</p>

<p>Rye Flour 5.62mg</p>

<p>Calf's liver 5.45mg</p>

Question 3

<p>Zinc: Role</p>

Answer 3

<p>Reproduction</p>

<p>Endocrine</p>

<p>Cell Proliferation</p>

<p>Sensory Function</p>

<p>Immunity and antioxidant</p>

<p>Digestion</p>

Question 4

<p>Zinc: Reproduction - Functions</p>

Answer 4

<p>• Production of sex hormones (↑ zinc usage during adolescence)<br></br>• Required for spermatogenesis<br></br>• Inhibits 5a reductase (e.g. inhibits the conversion of testosterone to the more potent androgen DHT).<br></br></p>

Question 5

<p>Zinc: Reproduction - Therapeutic Uses</p>

Answer 5

<p>• Infertility (male & female)<br></br>• Erectile dysfunction<br></br>• Low testosterone<br></br></p>

Question 6

<p>Zinc: Endocrine - Functions</p>

Answer 6

<p>• Needed for T4 to T3 conversion</p>

<p></p>

Question 7

<p>Zinc: Endocrine - Therapeutic uses</p>

Answer 7

<p>•Thyroid health<br></br></p>

Question 8

<p>Zinc: Cell Proliferation - Functions</p>

Answer 8

<p>• Needed for cell proliferation (e.g. in the skin) and differentiation.<br></br>• Required for DNA binding proteins involved in gene expression<br></br>• Aids tight junctions (i.e. in skin/GIT)<br></br></p>

Question 9

<p>Zinc: Cell Proliferation - Therapeutic uses</p>

Answer 9

<p>• Wound healing<br></br>• Acne<br></br>• Cancer<br></br>• Cirrhosis<br></br>• Burns</p>

Question 10

<p>Zinc: Sensory Function - Functions</p>

Answer 10

<p>• Sense of taste and smell (taste buds contain Zn containing enzymes)<br></br>• Supports vision and hearing.<br></br></p>

Question 11

<p>Zinc: Sensory Functions: Therapeutic Uses</p>

Answer 11

<p>• Poor taste / vision / Olfactory issues<br></br>• Tinnitus<br></br></p>

Question 12

<p>Zinc: Immunity and antioxidant - Functions</p>

Answer 12

<p>• An important antioxidant.<br></br>• Increases phagocyte, natural killer cell, T and B cell activity.<br></br>• Anti inflammatory (↓ inflammatory cytokines; e.g. interleukin 6 & TNF-a)<br></br></p>

Question 13

<p>Zinc: Immunity and antioxidant - Therapeutic Uses</p>

Answer 13

<p>• Anti viral activity: inhibits replication<br></br>• Frequent infections<br></br>• Inflammation<br></br>• Cardiovascular disease<br></br></p>

Question 14

<p>Zinc: Digestion - Functions</p>

Answer 14

<p>• Needed for the production of HCl<br></br>• Used to create pancreatic enzymes<br></br></p>

Question 15

<p>Zinc: Digestion- Therapeutic Uses</p>

Answer 15

<p>• Weak digestion<br></br>• Hypochlorhydria</p>

Question 16

<p>Zinc: Absorption</p>

Answer 16

<p>• Zn absorption ranges from 20-40% depending on the bioavailability of the food source.<br></br>• Protein generally enhances absorption but phytates in plants form a complex with Zn and inhibit absorption.<br></br>- Phytates are highest in wholegrains, legumes, nuts and seeds (phytate levels can be reduced by soaking, sprouting and fermenting).<br></br>• Excess Ca, Cu and non-haem Fe may also inhibit Zn absorption (e.g. simultaneous intake of milk or cheese can decrease Zn absorption).<br></br>• Note: Zn supplementation antagonises Cu absorption.</p>

Question 17

<p>Zinc Deficiency</p>

Answer 17

<p>• Deficiency is fairly common and can be caused by malabsorption, a diet high in phytates or low intake of Zn rich foods.<br></br>• Groups at an increased risk: older adults, alcoholics, pregnant women and athletes.</p>

Question 18

Zinc Deficiency Signs and Symptoms

Answer 18

• Poor sense of taste and smell.
• Recurrent infections , delayed wound
• Skin disorders (e.g. acne) , dandruff, white spots on finger
• Infertility (male and female) and low libido.
• Signs of weak digestion (e.g. bloating, fatigue)

Question 19

<p>Zinc Supplementation</p>

Answer 19

<p>• When using Zn supplements, the best absorbed form appears to be Zn picolinate but Zn citrate, Zn acetate and Zn glycinate are also well absorbed.<br></br>• Typical supplemental dosage is between 15-25mg/day and it’s advised to take with food as taken on an empty stomach can cause stomach upset.</p>

Question 20

<p>Zinc Toxicity</p>

Answer 20

<p>• Long term intakes in excess of the TUL (40mg) may lead to Cu deficiency and for this reason supplement manufacturers often include 1-2mg Cu.</p>