Unit 10 Water and Minerals PDF

Water and Minerals UNIT 10 NUTR 1100- Introduction to Nutrition Unit 10: Outline Nutritive values Functions Food sources Dietary requirements Absorption Consequences of deficiencies Water & Electrolytes Maintaining fluid balance Structure Lecture content...

Water and Minerals UNIT 10 NUTR 1100- Introduction to Nutrition Unit 10: Outline Nutritive values Functions Food sources Dietary requirements Absorption Consequences of deficiencies Water & Electrolytes Maintaining fluid balance Structure Lecture content Overview of Minerals Calcium Iron Water and electrolyte balance Independent study Review summary Table 8.7A & 8.19 (to understand that there are other minerals)- Do not memorize. Minerals Micronutrient: nutrients needed in small amounts Minerals: elements needed in the body to maintain structure & regulate chemical reactions & body processes. Major minerals – required in diet > 100mg/d OR in body >0.01% of body weight. Minor minerals – required in diet animals & cooking loss. Used as a preservative (e.g., sodium), fortification/enrichment. Eat a variety of foods to ensure adequate intake. Water & Electrolytes 1. Intracellular (inside cells) 2/3 of total body water 2. Extracellular (outside cells) Blood & Lymph Digestive juices Between the cells (intercellular or interstitial) Role of Water in the Body 1. Transportation (osmosis > to dilute dissolved solutes) a) Nutrients digestive tract  liver  cells b) Waste products cells  kidneys c) Oxygen & CO2 lungs  cells cells  lungs Did you know? Water 2. Part of molecules in 3. Chemical reactions (metabolic reactions) Brain - 75% 4. Solvent for molecules Bones - 25% Blood- 85% 5. Acid-base balance 6. Lubricant & cushion around joints 7. Shock absorber 8. Temperature regulation 9. Maintain blood volume & blood pressure 10. Softens fecal matter Water distribution Difference in concentration of dissolved substances alters water distribution Concentration differences drive OSMOSIS- diffusion of water in a direction that equalizes the concentration of solutes (proteins, Na, K and other small molecules) Small molecules are charged and since water has positive and negative charge, attract water into the blood stream to equalize the distribution. Blood pressure - regulates water distribution- low pressure –water drawn to capillaries  Water Balance Inside / outside of cells - determined by electrolytes Impact performance Within the body… Determined by intake & excretion of water Kidneys regulate urinary losses & concentration of solutes. Regulated by hormones (antidiuretic hormone, angiotensin II, aldosterone) If we don’t drink… we become dehydrated & sodium concentration increases the body works to retain water for hydration balance If we drink more water than usual… the body works to increase sodium to maintain balance.  Water Balance To maintain water balance, intake must equal output Intake: consume water, fluids, foods & production during cellular respiration Output: excretion in urine & feces, sweating & evaporation from the skin & lungs. Water loss Water loss depends in activity, temperature, humidity. Inactive person- 1L Light activity at 29 degrees- 2 to 3 L Strenouous activity in hot- 2 to 4 L Thirst Activated when Blood volume decreased Increase in solutes in blood  dry mouth , thirst center of brain tell you to drink Problems Often, thirst slower need Can be ignored especially in elderly dehydration Increased water loss stimulates thirst Kidneys and hypothalamus Role of Kidneys Regulate body water Kidneys act as a filter Water moves from the blood into kidney tubules Blood cells and proteins are too large and remain in the blood Needed substances are reabsorbed back into the blood Substances not needed by the body, such as toxins and wastes, are excreted in urine Hormones ADH (Antidiuretic hormone) Angiotensin II Aldosterone Risk of dehydration Mild symptoms of dehydration Thirst Dizziness Dry lips and mouth Fainting Tiredness Low blood pressure Dark smelling urine Increased heart rate Headache Irritability Muscle cramps  Antidiuretic hormone (ADH) Increased Decreased ADH Water reabsorption Extracellular blood secretion Na, Low BP Stimulate thirst Sodium Low blood vasoconstriction Less water volume excreted in urine Increase BP Risk of dehydration Severe symptoms of dehydration Blue lips Cold hands and Blotchy/dry skin feet Confusion Rapid breathing Lack of energy Unconsciousness Over hydration Water intoxication Rarely occurs form drinking too much water, but possible. Drink small amount of water at regular intervals. Adequate consumption of electrolytes. Disorder in ability to excrete urine / water retention. Causes hyponatremia. Level of sodium around the cells abnormally low. Body’s water levels rise & cells begin to swell. Weight gain is a warning sign. Can eventually result in death.  Abnormal fluid accumulation in body tissues. How much fluids are we drinking? 19-30y Men-2.6L (1.36L) Women-2L (1.2L) 31-50y Men-2.3L(1.1L) Women- 2.2L(1.3L) 71y and older- 1.5L (~800ml) cchs 2.2 Water Recommendations Don’t wait until you become thirsty & drink regularly Varies depending on gender, activity level & illness/trauma  Women: 2.7 L/day  Men: 3.7 L/day Increased needs in warmer climate & during exercise. Influenced by diet: low-calorie diet > increases water needs for metabolism High-salt diet > increases water losses in urine. High-fibre diet > increase water held in intestine in feces. Bottled water vs tap water Label- bottled water comes from tap- needs labelling Municipal water supplies- Distilled/purified water Dasani- municipal tap water on Calgary and Brantford, filtered and sold (3000% mark up) Cost and environmental impact Electrolyte Balance Sodium (+ charge; extracellular ion – outside cell) Potassium (+ charge; intracellular ion – inside cell) Chloride (- charge; extracellular ion – outside cell) Deficiency: Results in: acid–base imbalance, poor appetite, muscle cramps, confusion, apathy, constipation, irregular heartbeat, death Caused by: heavy/persistent sweating, chronic diarrhea or vomiting, kidney disorders, or medications Excess: Excess potassium from supplements can cause the heart to stop Excess sodium from consumption or dehydration also cause acid-base imbalance  Bones Protein matrix: mostly collagen; living tissue Hardened by minerals: mostly calcium, phosphorus, also magnesium, sodium, fluoride, other minerals Require: Protein & vitamin C to maintain collagen Calcium, phosphorus & other minerals to ensure solidity (Hydroxyapatite) Vitamin D to maintain calcium & phosphorus Strength exercise Support weight and participate in movement Constantly broken down (osteoclasts) and re-formed (osteoblasts) during bone remodeling Peak bone mass: maximum bone density attained during life, usually in young adulthood Osteoporosis: more bone loss than formation resulting in fractures Calcium Calcium is most abundant nutrient in the body 0.9 kg of Ca in a 60 kg body (1.5% body weight) 99% in bones & teeth (structure/storage) 1% in blood (calcium homeostasis – tight control): Muscle contraction Blood clotting Nerve impulse transmission Acid-base balance Hormone secretion Regulation of enzymes Maintaining blood pressure Calcium regulation Calcium in blood decreases Parathyroid hormone (PTH) produced in greater amounts  stimulates bone to release calcium  stimulates small intestine to absorb more calcium  causes kidneys to excrete less calcium in urine Calcium in blood increases Calcitonin (from thyroid)  stimulates building of bone Amount of PTH decreases Calcium needs 19-70y- 1000mg/d >70y- 1200mg/d (low absorption) Women- menopause- 1200mg/d Iron Blood: Red blood cells (Hemoglobin) Platelets white blood cells plasma Hemoglobin: transport oxygen to cells & carbon dioxide away (70-80%) Myoglobin: protein in muscles; stores oxygen in muscles ATP production (proteins in electron transport chain) DNA synthesis Immune function  Iron Losses & Recycling Losses of iron Loss of cells – mucosal, skin Blood loss Injury, traumatic or due to disease Blood donations Menstrual losses Recycling of iron- large amounts of iron is used from breakdown of RBC Lifespan of RBC + ~120 days (4 months) Then liver will collect older RBC  disassemble it Iron  bone marrow  new hemoglobin  Iron in Food Intake is low- efficient absorption by small intestine to compensate low intake but not excessive loss Bioavailability depends on source Animal source  60% bound to hemoglobin- Heme iron 40% is non-heme Based on hemoglobin & myoglobin in animal proteins Absorb ~25% but only 10-15% of iron in a mixed diet Plant based  only has Non-heme iron Whole grains, legumes, darjk green veg, enriched refined grains Poorly absorbed (2-10%) Impacted by other dietary factors (phytates, oxalates and tannins) Absorption of Non-Heme Iron Enhancers Inhibitors Vitamin C Phytates – legumes, grains, rice (provides an electron Fe3+  Fe 2+) ↓ absorption by 50% Organic Acids Tannins / tannic acid - tea Citric acid, Malic acid, tartaric, lactic acid EDTA – used in preserving colour Stomach acids Other nutrients Calcium & phosphorus Meat, fish & poultry, seafood Large zinc doses Adequate copper status Poly phenols – fruits, veg, coffee, tea, wines, spices, soy, bran.fibre Cooking in a iron pan DRI for Iron and Dietary sources Table 8.9 higher in infants and then adolescents- There is UL specified which means we know amounts beyond toxicity can occur Food sources in Table 8.10 Iron deficiency Anemia Insufficient iron levels- fewer and smaller RBC (low amounts of Hb) Fatigue Weakness Pale skin Shortness of Breath Abnormal heart rate Iron Supplements Iron deficiency anemia > supplements justified. Iron in supplements poorly absorbed vs. iron in food Ferrous iron: better absorbed than ferric iron Ferrous sulphate, ferrous fumarate, ferrous gluconate Absoption better if taken on an empty stomach But can also cause upset, constipation Vitamin C no help Proferrin: heme based (not for vegans) ~ 20x better absorption Elemental Iron is what is absorbed …absorption ↓ as dosage ↑ Dangerous for children unless prescribed and closely monitored