1 / 31

Minerals

Minerals. According to the body needs, minerals are divided into 2 groups:. I. Macrominerals:. They are required in amounts greater than 100 mg/day. They include: calcium, phosphorus, magnesium, sodium, potassium and chloride. II. Microminerals (trace elements):.

eljah
Download Presentation

Minerals

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Minerals According to the body needs, minerals are divided into 2 groups: I. Macrominerals: They are required in amounts greater than 100 mg/day. They include: calcium, phosphorus, magnesium, sodium, potassium and chloride II. Microminerals (trace elements): They are required in amounts less than 100 mg/day. They include: iron, copper, fluoride, iodine, manganese, selenium and zinc.

  2. Macrominerals Calcium Sources: Milk, milk products, beans and egg yolk. Absorption: By active transport system in the upper small intestine by the help of vitamin D (1,25 dihydroxy cholicalciferol). Body calcium: calcium is the most abundant mineral in the body. Most of calcium (99%) is present in the skeleton (bones and teeth), the remaining 1% are present in body fluids and other tissues Plasma calcium: normal level ranges from 9-11 mg/dl

  3. Hormonal regulation of Plasma calcium: 1. Calcitonin: is secreted from thyroid gland in response to increased blood Ca level. It decreases Ca through: • Mobilization of calcium from blood into bone • Decrease Ca reabsorption by renal tubules 2. Parathyroid hormone (PTH): secreted from parathyroid gland in response to decreased calcium levels. It increase calcium by: • Mobilization of calcium from bone to blood (bone resorption) • Increases Ca reabsorption by renal tubules • Increase absorption of calcium from small intestine through stimulation of vitamin D activation.

  4. Factors affecting calcium absorption • A- Factors affecting Ca absorption: 1-High protein diet: amino acid forms soluble salt with calcium. 2-Ph: an acidic PH is essential for calcium absorption. 3- High lactate or citrate that form soluble salts with calcium.

  5. Factors affecting calcium absorption B- Factors inhibiting Ca absorption: 1- High diet phosphate, oxalate, phytate form insoluble salt with CA. 2- Alkalinity: Ca absorption( treatment of peptic ulcer). 3- Fatty acid: insoluble Ca soaps with Ca.

  6. Function of Calcium • 1- Unionized Calcium: A- It enters in the structure of bone and teeth. 2- Ionized calcium: A- Transmission of nerve impulses. B-Contraction of muscles. C- Decrease of neuromuscular excitability. Deficiency of ionized calcium lead to tetany. D- Blood and milk clotting. E-Maintenance of cell membrane permeability. F- Activation of certain enzyme e.g. pyruvate kinase. G- Medication of some hormone responses e.g. it acts together with calmodulin as third messenger for hormone depending on cyclic AMP.

  7. Hypercacemia: may be due to: • Hyperparethyrodism due to adenoma ( benign tumor of the gland) • Excess intake of vitamin D or calcium • Milk-alkali syndrome : patients who receive milk and alkalies for long time, for treatment of peptic ulcer • Drugs such as thiazide diuretics Hypocacemia: due to: • Hypoparathyrodism • Renal disease where activation of vitamin D is inhibited Requirments: • Adult: 800 mg/day • Children, pregnant and lactating women: 800-1200 mg/day

  8. Phosphorus • Source: Milk meat and leafy vegetables • Absorption:By active transorport and regulated by Vitamin D • Factors affect of ca absorption also affect that of Phosphorus. • Body Phosphorus : Most of it present in bone and teeth. In the form hydroxy apatite: 3 Ca3(PO4)2.Ca(OH)2 • Blood phosphorus 3-5 mg/dl.

  9. Factors Affecting blood phosphorus • 1- Parathyroid hormone: A- PTH decrease blood phosphorus by stimulating its excretion (through inhibiting its renal tubular re absorption). • 2- Active Vitamin D (calcitriol): • A- Hypophosphatemia stimulates directly the renal hydroxylation of 25 (OH)D3 into 1,25 (OH)D3 (Calcitriol). • B- Calcitriol increases blood phosphorus through stimulation of: • 1- Absorption of phosphorus from the intestine . • Bone resorption i.e. mobilization of phosphorus from bone. • Renal reabsorption by renal tubules.

  10. Function of Phosporus 1-It enters in the structure of bone and teeth. 2- It enters in the structure of the following cellular components: a- Nucleic acids DNA RNA B- Phospholipids e.g. lecithin , cephalin. C- Phosphproteins. D- Coenzyme e.g. NAD, NADP. E- High energy phospate compounds e.g Atp, GTP,creatine phosphate. F- Cyclic Amp and Cuclic GTP. G- Carbohydrate intermediates e.g. glucose 6 phospate, fructose -1-p. 3- it enters in the formation of blood buffers.

  11. Sodium Sources: The main source is table salt Absorption: from small intestine (ileum). It is nearly completely absorbed. Body sodium: 2/3 of sodium is present in tissues and body fluids. About 1/3 is present in skeleton (bone and teeth) Requirements: 5 g/day Alterations of plasma sodium: Hypernatremia: excess plasma sodium is caused by: • Cushing syndrome. • Conn's disease due to excessive aldosterone secretion • Diabetes inspidus due to rapid loss of water • Drugs such as cortisone

  12. Hyponatremia: decrease plasma sodium caused by: • Addison's disease: due to deficiency of aldosterone • Renal failure where renal reabsorption of sodium is inhibited • Dehydration: due to loss of water and sodium • Thaizide diuretics which block renal reabsorption of sodium Toxicity of sodium: Hypertension in susceptible individuals. Functions: 1- maintentance of osmotic pressure and volume of plasma and extracellular fluid. 2-Transmission of nerve impulses. 3-Contraction of muscle. 4-Regulation of acid base balance.

  13. Potassium • Sources: • vegetables, fruits and nuts • Absorption: • Readily occur from small intestine • Body K: • 2/3 of potassium is present in tissues and body fluids. About 1/3 is present in skeleton (bone and teeth) • Requirements: 4 g/day Functions of potassium: The same of sodium except it act in intercellular fluid.

  14. Alterations of plasma potassium: Hyperkalemia: excess plasma potassium is caused by: • Addison's disease: due to deficiency of aldosterone • Acidosis • Tissue necrosis e.g. major trauma and burns due to leakage of tissue potassium • Chronic renal failure with oliguria • Uncontrolled D. M. Lack of insulin prevent potassium from entering cells Hypokalemia: decrease plasma potassium caused by: • alkalosis • treatment of hyperglycemia with insulin without taking potassium, as insulin helps potassium ion to enter cells • Excessive vomiting and diarrhea • Cushing syndrome • Diuretics therapy.

  15. Chloride Functions: • Chloride is the main extracellular anion. Together with sodium, it maintains the osmotic pressure and volume of plasma and extracellular fluid. • Chloride ions is essential for formation of HCl in the stomach. • Activation of enzyme:Cl activates salivary and pancreatic amylase enzymes.

  16. Maganisum • Functions: 1- it enters in the structure of skeleton (bone and teeth). 2-It activates many enzyme e.g. kinase enzyme. 3- it is required for transport of other cation (Ca. Na, K) across the cell membrane . 4- it is important for muscle contraction, nerve impulse transmission and it decrease neuromuscular excitability.

  17. Microminerals (Trace elements) IRON Sources: Liver, heart, kidney, spleen, and fish Sugarcane syrup (molasses), dates and egg yolk N.B. Most of dietary iron is present in the ferric state. Absorption: from small intestine. Usually 10-20% of dietary iron is only absorbed. Iron is absorbed in ferrous state. Reducing substances such as vitamin C and SH- of cysteine of dietary protein help the reducing of ferric ions into the absorbable form (ferrous state). Body iron: The total body iron of adult is 3-5 g distributed as follows: I -RBCs iron ( haemoglobin) is about 65% of total iron II- Tissue iron (32%): includes

  18. Available forms (28%) i.e. can be used when there body need 1-Ferritin : is the main storage form of iron. Composed of protein (apoferritin + iron). Present in iron stores: liver, spleen, bone marrow and intestine. 2- Haemosiderin: These are granules composed of iron, protein and polysaccharides. Used as another store of iron Non available forms (4%): can not be used even there is body need. All these forms are hemoprotein i.e. contain heme ring. Examples are: • Myoglobin: present in muscle and heart • Cytochromes: a, b and c: act as electron carriers • Catalase and peroxidase: act to destroy H2O2 III- Plasma iron: present in the form of: 1-plasma iron : ranges from 60- 160 μg/ dl 2- Transferrin : is a glycoprotein which carry iron in ferric state.

  19. Transport and storage of iron: • Absorbed iron enters in the portal blood in the ferrous state. • In the plama it is rapidly oxidized to ferric state by the help of protein- containing copper called: Ceruloplasmin • Then ferric ions are carried by transferring, which is\taken mostly by bone marrow to synthesize hemoglobin • Iron from iron stores (ferritin) can be released into plasma and carried by transferring to be used by B.M. and other tissues Requirements: • adults: 10 mg/day • Pregnant and lactating female: 30 mg/day

  20. Copper Sources : Most diet provides the amount of copper needed per day. Absorption : Mainly in the upper small intestine Body copper : 64% of copper are found in muscles and the remaining in other tissues including liver and bones. Plasma copper : 90 μg/ dl. Functions: 1- copper is essential for: A-Homoglobuin synthesis. B- Bone formation. C- mantence of mylin of the nerve. 2-Copper is essential component of several metaloenzymes such as: A-Ceruloplasmin: which oxidizes ferrous into ferric in plasma B-Superoxide desmutase: antioxidant enzyme C-Cytochromeoxidase

  21. 3- copper activates many enzyme e.g. uricase and dopamine hydroxylase. Requirements:2-3 mg/day Alterations of plasma copper: Hyper cupremia (Excess copper and ceruloplasmin) occur in infections and malignancies Hypocupremia (decreased plasma copper):occure in a disease called Wilson's disease in which copper accumulate in large amounts in: • Liver causing liver cirrhosis • cornea causing greenish- brown color of the corneal margine Kidney causing damage of renal tubules leading to increased excretion of copper and ceruloplasmin resulting in low plasma copper.

  22. Iodine • The only function is formation of T3 and T4 from thyroid gland, so deficiency of iodine leading to hypothyroidism and disease called Simple Goiter. • Requirements: 100-150 μg/day

  23. Zinc Functions of zinc: • Zinc is essential for growth and reproduction. • It plays a role in tissue repair and wound healing • Zinc forms a complex with insulin in β cells of the pancreases. this helps crystallization ,storage and release of insulin. • Zinc is essential component of a number of enzymes e.g.: • A- alkaline phoshatase. • B- Carbonic anhyrase. • C- Superoxide dismutase. • D- Carboxy peptidase.

  24. Zinc 5- Zinc is required for mobilization of vitamin A from the liver and subsequently maintain the normal concentration of vitamin A in plasma. Zinc deficiency: it causes: • Hypogonadism. • Poor healing of wounds. • Poor appetite and retard growth in children. • Liver cirrhosis.

  25. Selenium • A_selenium is an essential component of the enzyme glutathione peroxide (GSH-PX) which catalyzes the reaction: 2 GSH+H2O2 GSH-PX GSSG +2 H2O • B- This reactions as protective mechanism agonist the oxidative damage of hydrogen peroxide (H2O2) and fatty acid hydroperoxide by destroying them: • In RBCs, it protect heamoglobin and red cell membrane. • In the liver, it is important for detoxifying liquid hydroperoxides. • In the lens tissue of the eye< it prevents its oxidative damage.

  26. Selenium • Deficiency of selenium (GSH-PX): it causes: • Hemolytic anemia. • Liver cirrhosis • Cataract.

  27. Manganese • A- Manganese is essential for: • Normal bone structure. • Reproduction (spermatogenesis and ovulation). • Normal function of the CNS. • B- Manganese is component of: • Pyruvatecarboxylase enzyme. • Superoxide dismutase enzyme. • C- Manganese activates the arginase enzyme.

  28. Cobalt • A- coblet is a component of Vitamin B12 which is nessary for normal blood cell formation. • B- Cobalt gives vitamin B12 its red colour. • C- Enzyme requrining Vitamin B12 for their activites are: • Methylmalonyl COA mutase. • Methyletrahydrofolateoxidoreductase. • Homocysteninemethytransferase. • Ribonuclotidereductase. • D- Deficiency of Vitamin B12 causes pernicious anaemia .

  29. Chromium • It acts only together with insulin to promote glucose utilization. • Its deficiency leads to impairment of glucose utilization by tissue.

  30. Molybdenum • It is a component of oxidase enzymes e.g.Xanthine oxidase.

  31. Flouride • It increase the hardness of bone and teeth. • Its deficiency causes dental carries and osteoporosis. • Nowadays, it is supplied in drinking water. • Excess fluoride leads to fluorosis: mottling and discoloration of the enamel of teeth and changes in bones.

More Related