Micronutrients – Trace Minerals

1. Micronutrients – Trace Minerals

2. Micronutrients – Trace Minerals • Trace minerals • Because quantification of these minerals was difficult using available analytical techniques, these were called trace minerals • Typically needed by the body <100mg/day • Some of the minerals are required by the body <1mg/day. These are called ultra-trace minerals (fluoride, boron, arsenic, nickel, silicon…) • Very little is known about ultra-trace minerals

3. The Trace Minerals • Needed in much smaller amounts • Are essential • Difficult to study due to the trace amounts needed by the body • Animal sources of mineral are generally better absorbed.

4. Micronutrients – Trace Minerals • IRON (Fe) • Human body contains about 2-4 g of iron • Nearly 35-38 mg / kg body weight – women • Nearly 50 mg /kg body weight – men • More than 65% of the iron present in body can be found as part of hemoglobin • Rest of the amount found in myoglobin, part of enzymes and in storage • Stable oxidation state in body is ferric (Fe3+) and ferrous (Fe2+)

5. Micronutrients – Trace Minerals • IRON (Fe) - absorption • Heme iron (animal source) once digested is easily absorbed • Nonheme iron (plant source) absorption is influenced by many factors • Iron stored in liver, bone marrow and spleen

6. Absorption of Iron • Determined by body’s need • Acidic environment • Upper small intestine is absorption site • Hindered by phytic acid, oxalic acid, high fiber, high calcium, polyphenols • Zinc competes with iron for absorption

7. Micronutrients – Trace Minerals • IRON (Fe) - Functions • Main function in synthesis of hemoglobin in blood and myoglobin in muscle with essentially same function of carrying oxygen • Cytochromes involved in Electron transport chain contain iron • Iron essential for metabolism of some amino acids • Iron needed for carnitine and procollagen synthesis • Has many other functions

8. Micronutrients – Trace Minerals • IRON (Fe) – Functions

9. Micronutrients – Trace Minerals • IRON (Fe) – RDA & sources • Men – 8 mg/day • Women – 8.2 mg/day, pregnancy – 18 mg/day • Dietary iron is of two form heme and nonheme • Heme iron – part of porphyrin ring structure (mainly from animal sources – organ meats) • Nonheme iron mainly from plants

10. Micronutrients – Trace Minerals • IRON (Fe) – Deficiency • Found very often deficiency – low intake, absorption problems (Celiac disease…) • Major condition indicating the deficiency of iron is anemia with symptoms – fatigue, loss of appetite, Pica – (eating abnormal things), breathlessness because of low RBC…

11. Micronutrients – Trace Minerals • IRON (Fe) – Toxicity • Tolerable upper level is 45 mg • Prolonged use of supplements, accidental ingestion of large dose may result in toxicity • Genetic disorder hemochromatosis where iron absorption saturation is not observed and leads to deposition in all over the body • Cooking utensils role

12. Micronutrients – Trace Minerals • ZINC (Zn) • Human body contains about 1.5 – 3 g of zinc • Found in most of the organs of the body and body fluids • In body found as Zn2+

13. Micronutrients – Trace Minerals • ZINC (Zn) - absorption • Absorption occurs mainly in proximal small intestine • Both by diffusion and carrier mediated absorption • Several factors influence absorption • Zn stored mainly in liver, but can be found in all body parts

14. Micronutrients – Trace Minerals • ZINC (Zn) – absorption

15. Micronutrients – Trace Minerals • ZINC (Zn) - Functions • Enzyme constituent – part of metalloenzymes and perform different functions • Immune system – protein bound zinc is found in WBC • Zn has role in rapidly developing tissues and shows significant effect on reproductive organs health • Zn interacts with insulin in the pancreas • Zn required for normal function of hemoglobin and taste and smell

16. Micronutrients – Trace Minerals • ZINC (Zn) – Functions

17. Micronutrients – Trace Minerals • ZINC (Zn) – RDA & sources • For men – 11 mg/day • For women – 8 mg/day • Zn found in food generally complexed with amino acids and nucleic acids • Good sources are red meats, oyesters… • Whole grains represent plant sources

18. Micronutrients – Trace Minerals • ZINC (Zn) – Deficiency • Deficiency generally results of poor nutrition, absorption problems and alcoholism… • Growth retardation in children • Skeletal abnormalities due to defective collagen synthesis and cross linking • Poor wound healing • Delayed sexual maturation • Alopecia – hair loss • Loosing sense of smell • Other generalized GI symptoms

19. Micronutrients – Trace Minerals • ZINC (Zn) – Toxicity • Excessive use of supplements like zinc gluconate results in toxicity • Symptoms… • Metalic taste • Nausea • Vomiting • Abdominal Cramps, bloody diarrhea • Excess Zn results in poor absorption of copper leading to copper deficiency

20. Micronutrients – Trace Minerals • COPPER (Cu) • Human body’s copper contents ranges from 50 – 150 mg • Like Zn, Cu is also found in all body tissues and fluids • In body exists as cuprous (Cu1+) or cupric (Cu2+) • Some times it is called iron twin because both are metabolized in the same way and function as component of many enzymes

21. Micronutrients – Trace Minerals • COPPER (Cu) - absorption • Cu generally found in food bound to organic molecules like amino acids of proteins • Thus digestion is needed to free Cu • HCl and pepsin facilitate the release of bound Cu • Absorbed mainly in its Cu2+ form • Absorption is mainly carrier mediated • Copper transporter (Ctr) 1 is mainly used • Also divalent mineral transporter (DMT)1 is used • Same factors effecting Zn absorption also effect Cu absorption • Liver stores most of the Cu

22. Micronutrients – Trace Minerals • COPPER (Cu) - Functions • Mainly functions as enzyme co-factor

23. Micronutrients – Trace Minerals • COPPER (Cu) – RDA & Sources • For adults 900g/day • Pregnancy and lactation – 1 1.3 mg,day • Richest sources are meats – organ meats and shell fish (oysters and lobsters) • Nuts (cashews), dried fruits, whole grains and cocoa are good plant sources

24. Micronutrients – Trace Minerals • COPPER (Cu) – deficiency • Low intake, prolonged use of proton pump inhibitors results in deficiency • Most common deficiency symptoms include anemia • Low number of neutrophils (neutropanea) • Depigmentation of skin and hair • Low immunity, bone abnormalities,

25. Micronutrients – Trace Minerals • COPPER (Cu) – toxicity • Comparatively rare but acute poisoning due to water contamination or accidental over ingestion • Tolerable upper intake level is 10 mg • Chronic toxicity results in hematuria, liver damage, kidney damage • Acute toxicity symptoms includes • Nausea • Vomiting • Diarrhea • Weakness, lethargy and anorexia

26. Selenium • Readily absorbed • Excreted through the urine and feces • Co-factor for glutathione peroxidase • Protects the heart and other cells from oxidative damage • Works together with vitamin E • Cancer prevention

27. Deficiency of Selenium • Muscle pain • Muscle wasting • Cardiomyopathy

28. Food Sources of Selenium • Fish, meat (organ meat), egg, milk, shell fish • Grains, seeds, nuts dependent on soil content • RDA for adults is 55 ug/day

29. Toxicity of Selenium • Upper Level is 400 ug/day • Garlicky breath • Hair loss • Nausea, vomiting • Weakness • Rashes • Cirrhosis of the liver

30. Iodine • Found in an ion form, iodide • Used for thyroid hormone synthesis • Regulates metabolic rate, growth, development • Thyroid gland enlarges (goiter) with low intake of iodide • Cretinism is the stunting of fetal growth and mental development as a result of low iodine diet

31. Food Sources of Iodine • Iodized salt (1/2 tsp. meets RDA for iodine) • Saltwater fish, seafood, dairy, grains • Sea salt is a poor source (loss during processing) • Plant source dependent on soil content • RDA for adult is 150 ug/day • (50ug to prevent goiter)

32. Toxicity of Iodine • Thyroid hormone synthesis is inhibited • “Toxic goiter” results • Upper Level is 1.1 mg/day

33. Mineral Pyramid