Minerals. minerals are elements of the periodic table more than 25 have been isolated 21 elements have been shown to be essential (excluding C,H, and.

Presentation on theme: "Minerals. minerals are elements of the periodic table more than 25 have been isolated 21 elements have been shown to be essential (excluding C,H, and."— Presentation transcript:

1 Minerals

2 minerals are elements of the periodic table more than 25 have been isolated 21 elements have been shown to be essential (excluding C,H, and O) minerals make up about 4 to 5% of body weight (for a 70 kg individual: 2.8 kg) many minerals are found in ionic form (others as ligands or covalent compounds)

3 Minerals Two categories: macrominerals > 0.005% microminerals < 0.005% macrominerals are essential at levels of 100mg or more per day for human adults microminerals are often referred to as trace elements

4 Macrominerals Cacalcium1200 grams Pphosphorus860 grams Ssulfur300 grams Kpotassium180 grams Clchloride74 grams Nasodium64 grams Mgmagnesium25 grams

5 Microminerals Ffluorine2.6Vvanadium0.018 Znzinc2.0Sntin0.017 Cucopper0.1Seselenium0.013 Iiodine0.025 Mnmanganese 0.012 Crchromium0.006 Ninickel0.010 Cocobalt0.0015Momolybdenum 0.009 Sisilicon0.024

6 Other microminerals found in humans Sr (strontium) Br (bromine) Au (gold) Ag (silver) Al (aluminum) Bi (bismuth) As (arsenic) B (boron) the function of these minerals has not been established as of to date

7 Scientific development which have contributed to trace element knowledge design of highly purified and specially constituted diets advances in analytical measurements colorimetruy fluorimetry flame photometry neutron activation analysis atomic absoption spectroscopy microwave excitation emission spectroscopy isolation and study of metalloenzymes

8 Functions of minerals provide a suitable medium for cellular activity –permeability of membranes –irritability of muscles and nerve cells play a primary role in osmotic phenomenon involved in acid base-balance confer rigidity and hardness to certain tissues (bones and teeth) become part of specialized compounds

9 Metalloenzymes metal is firmly bound metal to protein ratio is constant metal to enzyme activity ratio is constant metal is unique no enzyme activity without metal

10 Metalloenzymes Examples of metalloenzymes: –superoxide dismutase (Zn and Cu) –carboxypeptidase A (Zn) –carbonic anhydrase (Zn) –cytochrome oxidase (Fe and Cu) –xanthine oxidase (Co and Fe)

11 Metal-activated enzymes metal is reversibly bound metal to protein ratio is variable metal to enzyme activity ratio is variable metal is not necessarily unique enzyme activity may exit without metal

12 Metal-activated ezymes Examples of metal-activated enzymes –creatine kinase (Mg, Mn, Ca or Co) –glycogen phosphorylase kinase (Ca) –salivary and pancreatic alpha-amylases (Ca)

13 The electrolytes There are 3 major electrolytes: –sodium –potassium –chloride

14 Sodium (Na) Sodium is the principal cation in extracellular fluids functions include: osmotic equilibrium acid-base balance carbon dioxide transport cell membrane permeability muscle irritability

15 Sodium (Na) food sources: table salt, salty foods (potato chips, pretzels, etc.), baking soda, milk absorption and metabolism: –readily absorbed –excreted in the urine and sweat –aldosterone increases reabsorption in remal tubules

16 Sodium (Na) RDA for adults: 1.1 to 3.3 gm/day sodium deficiency: –dehydration –acidosis –tissue atrophy sodium excess: –edema (hypertonic expansion ) –hypertension

17 Sodium (Na) Sodium supplements: –usually used to replace sodium and chloride lost through perspiration during high heat Thermotabs Slo-salt Heatrol Lytren solution Pedialyte solution Gatorade and other sports drinks

18 Potassium (K) Potassium is the principal cation in intracellular fluid functions: –buffer constituent –acid-base balance –water balance –membrane transport –neuromuscular irritability

19 Potassium Food sources: vegetables, fruit (bananas), whole grains, meat, milk absorption and metabolism: –readily absorbed (more so than sodium) –intracellular –secreted by kidney (also in sweat) RDA for adults: 1.5 - 4.5 gm/day

20 Potassium deficiency (hypokalemia) –causes: increased renal excretion (diuretics) primary aldosteronism severe vomiting and diarrhea cutaneous losses via perspiration –symptoms: profound weakness of skeletal muscles (paralysis and impaired respiration weakness of smooth muscles cardiac anomalies: AV block, cardiac arrest

21 Potassium excess (hyperkalemia) –causes: sudden increased intake severe tissue trauma and burns acute and chronic acidosis –symptoms: weakness and paralysis cardiac anomalies (impaired conduction, fibrillations, cardiac arrest)

22 Potassium supplements Oral products: –tablets: potassium chloride, potassium gluconate, Slow-K –effervescent tablets: K-Lyte, K-Lor, Kaochlor –parenteral products: usually administered by slow IV infusion (KCl and K acetate)

23 Treatment of hyperkalemia reverse cardiotoxic effects: –calcium gluconate IV increase potassium uptake by cells: –dextrose (IV) –insulin (IV) –sodium bicarbonate (IV) remove excess potassium from the body: –sodium polystyrene sulfonate (Kayexalate)

24 Chloride (Cl) an essential anion closely connected with sodium in foods, body tissues and fluids and excretions readily absorbed along with sodium excreted mainly in the kidneys (~ 2% in feces and ~ 4-5% in perspiration ) important for osmotic balance, acid-base balance and in the formation of gastric HCl

25 Chloride (Cl) Deficiency of chloride: –hypochloremic alkalosis –hypovolemia –pernicious vomiting –psychomotor disturbances

26 Calcium (Ca) the most abundant of the minerals the 5th most abundant element in the body needed by all cells found in largest amounts in bones (90%) found in bone as hydroxyapatite Ca 10 (PO 4 ) 6 (OH) 2 contaminated with sodium, potassium, magnesium, carbonate and fluoride

27 Calcium (Ca) controlled by parathyroid hormone (PTH), calcitonin and vitamin D maintained at a concentration of 5 mEq/L in plasma about 1/2 is in the ionized form in serum the other 1/2 is bound to protein (calcium citrate complex)

28 Calcium (Ca) function of calcium: –structural unit of bones and teeth –contraction and relaxation of muscles –stabilizes nervous tissue low calcium --- irritable nerves --- tetany high calcium --- depresses the nervous irritability –required for blood clotting –activates various enzymes (glycogen phosphorylase kinase, salivary and pancreatic amylase)

29 Calcium (Ca) Calcium absorption: –variable due to insoluble salts: phosphate carbonate oxalate phytate sulfate –also forms calcium soaps with fatty acids absorption is enhanced by: acid pH vitamin D lactose lysine and glycine

30 Calcium (Ca) Excretion: –urine and feces –enhanced by lack of vitamin D and ingestion of large quantities of proteins (acid urine) RDA –adult: 800 mg/day –pregnacy and lactation: 1200 mg/day

31 Calcium supplements calcium gluconate: 9% calcium lactate 13% calcium carbonate 40% dibasic calcium phosphate 30% calcium glucobionate 6% calcium chloride 27.2% calcium levulinate 13%

32 Phosphorus required in many phases of metabolism food sources: –phosphoproteins –nucleoproteins –nucleolipids –glycerophosphates –inorganic phosphates (Na and Ca) foods rich in calcium are also richest in phosphorus (milk, cheese, eggs, beans, fish)

33 Phosphorus Phosphorus is the second most abundant mineral in the body (22% of total mineral content; 80% is structural – insoluble apatite in bone and teeth) 20% is very active metabolically: High energy phosphate compounds Nucleic acids Phospholipids Phosphoproteins Coenzymes (vitamins)

34 Phosphorus RDA for phosphorus is established on the basis of a 1:1 relationship with calcium –Adults: 800 mg/day –Pregnancy and lactation: 1200 mg/day Phosphorus deficiency (hypophosphatemia) Not common May be associated with total parenteral nutrition (TPN) without sufficient phosphates; give either sodium or potassium phosphate

35 Magnesium (Mg) second most plentiful cation in intracellular fluids ~50% of total amount in bone ~45% in muscle and nervous tissue ~ 5% in extracellular fluids blood plasma magnesium : ~ 2 mEq/L

36 Magnesium (Mg) Functions: a. enzyme systems –cofactor of all enzymes involved in phosphate transfer reactions that use ATP and other nucleotide triphosphates –phosphatases –pyrophosphatases

37 Magnesium (Mg) b. CNS –hypomagnesemia ---- cns irritability, disorientation, psychotic behavior, convulsions c. neuromuscular system: –magnesium has a direct depressant effect on skeletal muscle –magnesium also causes a decrease in Ach release at motor end plate (used in treatment of eclamptic seizures)

38 Magnesium Abnormally low concentrations of Mg in the extracellular fluid ---- increased Ach release ---- increased muscle excitability (tetany) food sources: all green plants (chlorophyll); meats RDA: 350 mg/day –pregnancy and lactation: 450 mg

39 Zinc Biological roles –Involved in many enzymes (over 20 metalloenzymes) Carbonic anhydrase Carboxypeptidase A –Four types of proteases »Serine »Cysteine »Aspartic acid »Zinc ACE (angiotensin I convering enzyme) RNA and DNA polymerases

40 Zinc zinc absorption appears to be dependent on a transport protein, metallothionein deficiencies include poor growth, delayed wound healing, impairment of sexual development and decreased taste acuity zinc is present in gustin, a salivary polypeptide that is necessary for the development of taste buds

41 Zinc severe zinc deficiency is seen primarily in alcoholics (especially if they have developed cirrhosis), patients with chronic renal disease or severe malabsorption diseases occasionally seen in patients on long term total parenteral nutrition (TPN) –patient develop a dermatitis zinc is occasionally used therapeutically to promote wound healing and may be of some use in treating gastric ulcers

42 Zinc supplements

43 Iron (Fe) 2 types of body iron –heme iron hemoglobin, myoglobin, catalases, peroxidases, cytochromes (a, b and c – involved in electron transport), cytochrome P450 (involved in drug metabolism) –non-heme iron ferritin, hemosiderin, hemofuscin, transferrin, ferroflavoproteins, aromatic amino acid hydroxylases food iron is also classified as heme and non- heme

44 Food iron heme iron –meats –poultry –fish 20-23% of heme-iron is absorbable non-heme iron –vegetables –fruits –legumes –nuts –breads and cereals only ~ 3% on non heme iron is absorbed

45 Iron absorption occurs in upper part of small intestine about 10% of food iron is absorbed requires gastric HCl (releases ionic iron) also requires copper ferrous is better absorbed than ferric form Fe ++ forms chelates with ascobic acid, certain sugars and amino acid

46 Iron distribution and storage carried in blood stream via transferrin (a b globulin) stored in 2 forms: ferritin (a water soluble complex consisting of a core of ferric hydroxide and a protein shell (apoferritin) hemosiderin (a particulate substance consisting of aggregates of ferric core crystals) stored in liver, spleen, bone marrow, intestinal mucosal cells and plasma

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48 Iron elimination there is no mechanism for excretion of iron iron is normally lost by exfoliation of intestinal mucosal cells into the stools trace amounts are lost in bile, urine and sweat (no more than 1 mg per day) bleeding (vaginal, intestinal) is a more serious mechanism of elimination

49 IRON DEFICIENCY Initial symptoms are vague and ill-defined easy fatigability lack of appetite headache dizziness palpitations then: hypochromic-microcytic anemia microcytosis (small RBCs) hypochromia (poor fill of hemoglobin) poikilocytosis (bizarre shapes) anisocytosis (variable sizes)

50 IRON DEFICIENCY Causes: –excessive blood loss (parasitic, accidental, menstrual): is most common cause –rapid growth in children with limited intake of iron –malabsorption gastric resection sprue –increased metabolic requirement pregnancy, lactation or neoplasia

51 Diagnosis of iron deficiency hematology (microcytic hypochromic cells) low serum iron low serum ferritin( indicates low body stores) in some conditions (inflammation, hepatitis) ferritin may be high low hemosiderin high total iron binding capacity (TIBC)

52 Iron absorption average diet contains 10 - 15 mg of iron perday a normal person absorbs 5 -10% of this iron or 0.5 - 1.0 mg daily iron absorption increases in response to low iron stores menstruating women: 1 - 2 mg per day pregnant women: 3 - 4 mg per day absorption is via active process

53 Different types of iron Ferrous sulfate20% Exsiccated ferrous sulfate ferrous gluconate11.6% ferrous fumarate33% ferrocholinate12% polysaccharide-iron complex iron dextran (Imferon)

54 Treatment of iron deficiency give 200 - 400 mg of iron per day up to 25% of the iron preparation may be absorbed 50 - 100 mg of iron may be utilized in case of deficiency give on an empty stomach enteric coated iron tablet should not be used since we want absorption to occur in the stomach and proximal duodenum

55 Treatment of iron deficiency parenteral iron is used in patients who have had bowel resections or in cases of inflammatory bowel disease –normally given IM (painful) Z-track minimizes tatoo oral iron causes black stools, constipation, cramping do not administer with antacids or metal chelators (tetracyclines)

56 Acute iron toxicity common in small children ingesting large doses of soluble iron compounds toxicity is usually divided into 4 phases: 1. 30 - 60 min. following ingestion abdominal pain nausea and vomiting signs of acidosis and cardiovascular collapse may be seen

57 Acute iron toxicity 2. Period of improvement - last about 8 to 16 hours 3. Period of progressive cardiovascular collapse (about 24 hrs after ingestion) convulsions coma high mortality 4. Gastrointestinal obstruction from scarring of stomach and small intestine

58 Deferoxamine mesylate (DFOM) A chelating agent which reacts with ferric ion to form a 1:1 chelate known as ferrioxamine Marketed as Desferal Injection (Ciba) Produced by Streptomyces pilosus

59 Chronic iron toxicity causes hereditary hemochromatosis hemosiderosis symptoms cirrhosis: iron deposition in the liver diabetes: iron deposit in the pancreas (damage to beta cells) skin pigmentation cardiac failure treatment: phlebotomy ( 1 unit of blood removes about 250 mg of iron

60 Copper important trace mineral element 29 on the periodic table component of several enzymes: ceruloplasmin (an oxidase) tyrosinase (production of melanin) amine oxidase (metabolism of catecholamines) cytochrome C oxidase dopamine beta hydroxylase copper/zinc superoxide dismutase

61 Copper (Cu) Deficiency –decreased iron absorption –neutropenia and leukopenia –bone demineralization –failure of erythropoiesis sources liver, shellfish, whole grains, cherries, legumes, nuts

62 Fluorine Considered essential because of its beneficial effect on tooth enamel Benefits include: less dental caries, stronger bones, reduction in osteoporosis and calcification of the aorta In large quantities it is deleterious to teeth; dental fluorosis: pitting, chalky, dull white patches and mottling of teeth 1 to 2 parts per million is adequate for drinking water

63 Iodine iodine is necessary for the formation of thyroid hormones (T-4 and T-3) deficiency of iodine is manifested by a goiter (enlargement of the thyroid gland) salt water fish and seaweeds are a good source of iodine to prevent the development of endemic goiter, tablet salt has been spiked with sodium iodide

64 Fluorine Main sources include drinking water and plants (spinach, lettuce, onions) Average daily intake: 1.5 – 4.0 mg/day Fluoride supplementation is available in both oral and topical forms: Oral: mainly sodium fluoride (Pediaflor Drops) Topical: either sodium or stannous fluoride (Fluorigard, Karigel, Fluoral)

65 Silicon essentiality has been established in chicks and rats, but not humans appears to play an important role in the development and maintenance of cartilage (chondroitin sulfate, hyaluronic acid, keratin sulfate) may have a protective role in cardiovascular diseases (atherosclerosis) found in unrefined grains and beer

66 Manganese Maganese is an activator of several different enzymes: Phosphoglucomutase Isocitric dehydrogenase Cholinesterase Intestinal peptidase Carboxylases ATPases However, magnesium and cobalt can replace Mn in several enzymes

67 Manganese Essential for sulfomucopolysaccharide biosynthesis Deficiency leads to: Weight loss Transient dermatitis Nausea and vomiting Changes in hair color Sources: blueberries, wheat bran, beet greens, lettuce, legumes, fruit RDA: 2.5 – 5.0 mg

68 Chromium Cr III may act as a cofactor for insulin, enhancing glucose utilization deficiency leads to impaired glucose tolerance (glucose tolerance factor) sources: corn oil, whole-grain cereals, clams, drinking water (variable) forms a coordination complex with micotinic acid and the amino acids glycine, glutamate and cysteine chromium may have a role in type 2 diabetes RDA: 0.05 – 0.2 mg frequently available in pharmacies as chromium picolinate

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70 Selenium prevents: muscular dystrophy in lambs, calves and chicks liver necrosis in rats and pigs exudative diathesis in chicks and turkeys multiple necrotic degeneration of heart, liver, muscle and kidneys in mice appears to function in the metalloenzyme glutathione peroxidase, which destroys peroxides in the cytosol no deficiencies have been seen in humans has antioxidant activity (may have relationship with vitamin E - sparing action)

71 Tin produces accelerated growth in deficient rats tin is similar to carbon in its tendency to form covalent bonds may have a role with heme-containing enzymes:heme oxygenase and cytochrome P-450 largest quantities are found in kidneys and skin human intake: ~ 1.5 - 3.5mg/day

72 Cobalt essentiality exists in some animals for ionic cobalt (sheep and cattle) in rats administration of cobalt produces a polycythemia cobalt in necessary in humans in the form of vitamin B12 animals and plants cannot synthesize B12 daily intake: 0.3 mg

73 Vanadium essentiality established in rats and chicks human daily intake has been estimated at 2 mg plays a role in lipid metabolism (deficient chicks have a high plasma cholesterol and triglyceride levels) may also function as an oxidation- reduction catalyst

74 Molybdenum Widely found in commonly used foods (cereals, vegetables Mo is part of flavoproteins, xanthine oxidase, aldehyde oxidase

75 Sulfur Most sulfur in the diet comes in from protein sources containing sulfur amino acids such as cysteine, cystine and methionine Some enters as inorganic sulfur (sulfate, sulfide, chondroitin sulfate and certain other sulfate esters) Sulfur is also present in thiamine, biotin, sulfolipids, conjugated bile acids and coenzyme A