Transcript Iron
Dr Ali Soroush Head of Department of Sports Medicine and Rehabilitation Chairman of Imam Reza Hospital MINERALS AND TRACE ELEMENTS • Are inorganic substances that are essential for the normal function and development of body cell and systems • They make up approximately 3% of total body-weight Functions of mineral in the body • Formation and maintenance of strength and Rigidity of bone and teeth • Regulation of fluid balance • Regulation of acid /base balance • Components of enzymes and hormones and , as such , essential for energy metabolism and functioning of the immune system • Transmission of action potential along nerves • Contraction of muscle fibres. Essential minerals and trace elements minerals trace elements Calcium Iron manganese phosphorus Fluoride chromium Potassium Copper selenium Sodium Zinc molybdenum Chlorine Iodine magnesium Cobalt Reference nutrient intakes, sources and effects of incorrect intakes UK RNI*/day Dietary sources Calcium Dairy product Phosphorous Dairy product Functions bone and teeth formation Muscle contraction Nerve transmission Blood clotting 700mg Deficiency symptoms Toxicity symptoms Rickets Osteoporosis Convulsion Stunted growth bone and teeth formation ACID –BASE BALANCE Deminerilisation of bone Low blood Ca levels 550mg Meat and fish Iron Meat, dried fruit , green vegetables fortified cereals Component of haemoglobin Pallor Tiredness Breathlessness Reduced resistance to infection Cirrhosis of liver Iodine Seafish and shellfish , milk some vegetables Iodised salt Component of thyroid hormones , controls metabolic rate Enlarged thyroid Foetal abnormality Retarded growth Hyperthyroid Flourine Seafood , tea, drinking water Helps prevent caries Increased frequency of dental caries Tooth mottling Skeletal changes Sodium Cheese preserved foods Pre-prepared foods added to cooking Acid-base and fluid balance Nerve transmission Muscle contraction Muscular fatigue , nausea Reduced appetite Hypertension vomiting 8.7 mg male 14.8 female 140 µg 50 µg 1600 mg RNI: Reference Nutrient Intake* Reference nutrient intakes, sources and effects of incorrect intakes (2) UK RNI*/day Dietary sources Functions Deficiency symptoms Toxicity symptoms Potassium Fruit , vegetables Acid-base and fluid balance , nerve transmission, muscle contraction Muscle weakness, confusion, cardiac arrest irregular heart rate Mg Wholegrain cereals, green vegetables , nuts Protein and DNA synthesis, bone development Neuro muscular dysfunction Hypertension Copper Meat , shellfish , vegetables Enzymefunction lon absorption Reduced resistance to infection -------- Zinc Meat , eggs , ,pulses , wholehrain cereals Enzyme function , immune system Skin lesions , growth failure , reduced immunity Diarrhea , nausea 3500 mg 300 mg 1.2 mg 9.5 mg RNI: Reference Nutrient Intake* Calcium (Ca) • • • • Greatest amount in the body The body of a well-nourished adult contains 1-1.5 kg ca 99% of total content is deposit in bones and teeth, 1% in blood and body fluids Functions Bone structure Nerve function Blood clotting Muscle contraction Cellular metabolism Functions of Ca • Deposits of Ca in the original soft matrix give bones their necessary rigidity. • In the case and resistance to decay. • The small amount of Ca remaining in the tissue fluids plays a part in controlling the action of nerves. • Ca also has a role in the clotting of blood. Absorption of calcium: – Mechanism predominantly in the jejunum but also in the ileum and colon. Simple diffusion An active transport involving Ca pump Absorption factors Absorption increased by Body need Vitamin D Fat Lactose Amino acid Arginine Absorption decreased by: Vitamin D deficiency Calcium-phosphorus imbalance Coca spinach Food Sources: Best sources: Milk and milk product; Good sources: Beans, vegetables, fish, cabbage,broccoli. Ca content of some dairy products and white bread • • • • 500 ml milk contains approximately 500 mg Ca 30 g cheddar cheese contains 240 mg Ca 125 g pot low-fat yoghurt contains 200mg Ca Two thick slices white bread contains 74 mg Ca Ca Deficiency Calcium may be lacking in the body if absorptions is impaired as in the: • Malabsorption syndrome • Vitamin D deficiency • Dietary deficiency of Ca in girls age 15-18 y Dietary requirement • During Pregnancy(no extra Ca is required because increase absorption) • During lactation (550mg per/day) • Throughout childhood and adolescence Calcium and Osteoporosis • Bone growth is greatest during “linear growth” – Peaks out at around age 35 Ca • Lose of cortical bone occurs at a rate 35% per year in males and in females prior to the menopause . The rate in a females for 5 years after menopause. • Ca supplementation without the addition of oestrogen can not prevent Osteoporosis. Phosphorous (P) • Second largest amount in the body • 80% of P occurs in combination with Ca in the bone and teeth. • 20% ECF Functions of Phosphorus • • • • Essential for the development of bones and teeth Phospholipids, Phosphoprotieon Energy metabolism Maintenance of blood pH: phosphate buffer system P Absorption • PTH absorption of P • phosphate is based on the intake of calcium.(the ratio of Ca:P of 1:1) • Sources: milk, fish, vegetable, meat, eggs – Phosphorus Deficiency • Patients with renal diseases. • Patients receiving TPN • Alcoholic Iron The function of Iron in the body are as follows: Iron is necessary for the formation of Hb Hb Carries of oxygen to the tissues and carbon dioxide between the lungs Part of the protein myoglobin in muscles Iron is found in the muscle pigment myoglobin It is also an important constituent of many enzyme systems Iron Iron absorption Not all the Iron in the diet is absorbed If the diet contains adequate amounts meat and ascorbic acid it is usual only 15% of dietary iron to be absorbed Iron absorption occurs in the duodenum and jejunum Sources of iron Two types of iron are found in foods: Meat and meat products contain haem iron (i.e.the iron in hemoglobin) Fruit and vegetables contain iron as ferric complexes Heme and Nonheme Iron in Foods Iron Deficiency Groups of the population who may suffer from iron deficiency are those with: Increased needs: pregnant women, Infants, toddlers, and Adolescents High losses: Mensturating women Poor or reduced absorption: Elderly people, Vegetarians Iron absorption mechanisms in the upper small intestine (McGeown 1999) High Iron Intakes Haemochromatosis: Is an inherited condition in which iron absorption is inappropriately high and results in an accumulation of iron in the tissues Iron poisoning: It does occur in children and adults Iodine The trace element iodine is a constituent of thyroxine (T4) and triiodothyronine (T3) These hormones control the rate of tissue activity, metabolic rate, integrity of connective tissue They are also necessary for the development of the foetal nervous system during the first trimester of pregnancy They are vital for normal and physical mental development Dietary Sources Iodine Vegetables Sea fish Cretinism results A deficiency in the mother’s diet during early pregnancy in cretinism, a syndrome of mental retardation and dwarfism Goitrogens Some foods have been found to contain substances which interfere with the uptake of iodine by thyroid gland such as sweet potato • Cabbage and turnip contain goitrogenic cyanoglucosides • Cassava, maize, sweet potato and lima beans • Water may have goitrogenic properties when contaminated with faeces • Calcium, fluoride, manganese and magnesiumions present in hard water are also goitrogenic Goiter • If sufficient Iodine is not available for formation T3 &T4 , the thyroid gland enlarges in an effort to maintain normal out put of hormones ,and gives rise to swelling of neck. Iodine Deficiency • Iodine Deficiency is prevalent in communities where dietary intake is low or insufficient or combination with a diet containing goitrogens. Goiter • • Endemic (commonl found) in parts of S. America and India Sporadic cases in U.S. Fluorine • Principally in matrix of bone and teeth. • This mineral is present in water and tea • Amount normal Fluorine is present in water to extent of 1 part per million Fluorine Deficiency • Deficiency symptoms – Susceptibility to tooth decay • Toxicity symptoms – Fluorosis (pitting and discoloration of teeth) Sodium Sodium is found principally in the blood plasma and the fluid surrounding the tissues. Na+ are important in maintaining and influencing osmotic balance between cells and the interstitial fluid Distribution is mediated by the Na+/K+-ATPase pump Na+ are important in neuron (brain and nerve) function – action potential Sodium dietary sources • • • • • • Common salt Fish Milk Egg Fruit & vegetables cheese • Sodium losses occur through urine and sweat (symptoms: excessive fatigue and muscle cramp) • Shifts in sodium balance result in expansion or contraction of ECF • Too low, ADH / aldosterone secreted • Too high, Atrial natriuretic peptide (ANP) • secreted • Normally , the sodium content of the body is maintained by the kidneys at an almost constant level. • Changes in the sodium concentration in the ECF are compensated for by changes in the ECF volume. • So is the ECF sodium concentration increases , more water is retained in the ECF to keep the constant concentration Sodium Absorption The absorption of sodium and water are under the complex hormonal control of aldosterone and ACTH. Change of ECF volume are detected by pressure sensors in the circulation , which stimulate changes in sodium and water absorption in the kidneys Signs & Symptoms of decrease in sodium • • • • • • • Muscle cramps Excessive fatigue Pathology Prolonged Vomiting or Diarrhoea Poor kidney function Excessive sweating Tissue damage In the elderly , Na deficiency can lead to confusion Dietary salt and hypertension • There is much conflicting evidence about the links between hypertension and dietary sodium intake • High alcohol intake , smoking , high salt intake and obesity contribute to rise in blood pressure Potassium K+ is the principal cation of the intracellular fluid. Potassium is present principally in body Excessive retention occurs in association with some kidney disorders and also in Addison’s disease, and may cause cardiac arrest Kidneys play important role to regulating the Potassium Content in body. Over 90% K absorbed in proximal small intestinal. Potassium sources Fruit and vegetables are the major contributors of potassium to the diet, bananas and fruit juices being particularly rich sources Coffee is also a good source Potassium and Blood Pressure Increasing the dietary potassium intake has been shown to reduce blood pressure in normotensive and hypertensive individuals Potassium Excessive retention • Kidney disorders • Addison’ s disease • Cardiac arrest Deficiency • Prolonged Vomiting • Diarrhoea • Diuretic therapy Magnesium Magnesium is a necessary for skeletal and maintaining electrical potenial across the membranes of nerves and muscles. Dietary sources • Hard water • Green vegetable • Meat and meat product Magnesium Deficiency Symptom of Magnesium deficiency Case Magnesium deficiency Starvation Alcoholism Prolonged Diarrhoea Prolonged vomiting • • • • Progressive muscle weaknss Failure to thrive Neuromuscular dysfunction VF Copper • Chief functions in the body – Necessary for absorption and use of iron in the formation of hemoglobin – Part of several enzymes – Copper Deficiency Symptom Deficiency – Defect hair pigmentation – Increased susceptibility to respiratory infection – Reduced immune response Zinc • • • • • 60% in skeletal muscle 30%in bone Part of many enzymes(metalloenzymes ) Needed for wound healing Zinc Deficiency: impaired immune , Growth failure, impaired healing • Zinc Toxicity: , copper deficiencies , nausea & vometing Factors predisposing to Deficiency • • • • • • • Lacking in diets Parasites causing chronic blood loss Excessive sweating Malabasorption of food Surgery burns Dietary sources : seafood ,meat, egg Selenium • acts with other antioxidants • May be protective froms cancer • Dietary sources: • Meats , fish Chromium • • • • Increases action of insulin Part of metabolism lipid Dietary sources: meats , nuts, Molybendum • Essential of some enzymes involved in the DNA metabolism • Dietary sources: • Milk , liver Cobalt • Constituent with vitamin B12 • essential for maturation of RBC’s • Dietary sources: • Meats ,milk Choloride • Balance Na & K in the cells and ECF • Dietary sources • Salt Aluminium • Aluminium is found all plats animals • Dietary sources • vegetable Water • Water constitutes about 65 - 70 % total body weight • Fluid balance between ECF & ICF • Products of digestion are absorbed in a fluid medium and distributed in blood and lymph • Controlled body temperature • Excretion (lung , kidney ,..) • Involve chemical reaction Water sources • Water is a constituent of most food , even though they may be solid in consistency: • Bread contains approximately 35% water • Fish 65% • Meat 50-70% • Vegetables and fruits 80-90% Water balance • Water is lost from the body in urine , faeces , sweat and expired air. • The regulatory mechanisms in the kidneys result in a variable volume of urine being secreted-consequently a balance is maintained between intake and output of water Requirement • An average adult living in a temperate climate requires approximately 2500 ml of water daily. • The actual amount that is ingested depends both on climate and habit : • Drinks provide 1000-2500 ml. • Food provide 1000-1500 ml. • Metabolism provide 200-400ml. Dehydration • Means loss of water , but is often used as implying a loss of certain mineral elements also , particularly sodium. • Loss of up to 5% of body-weight by dehydration results in thirst and discomfort. • Loss of 6-10% results in dizziness , absence of saliva and inability to walk. • Loss of 11-12% results in delirium , swollen tongue , inability to swallow and shrivelled skin Total body fluid Male 60% Female 50%