Nutrition Chapter 12Water and the Major Minerals-fluid within cell membrane has highest concentration of potassiumWater and the Body Fluids-carries nutrients and waste products-maintains structure of large molecules-participates in metabolic reactions-serves as solvent-acts as a lubricant and cushion-regulation of body temp-maintains blood volumeWater Balance- water constitutes 60% of adults body weight- most indispensible nutrient- thirst lags behind the body’s need for watero water intoxication (hyponatremia)sodium levels are so low in blood symptoms=confusion, convulsions, deathSigns of Dehydration p384 in bookWater Balance and Recommended Intake- Sourceso Watero beverages(not alcohol)o foods (fruits and vegetables)o condensation reactions- Losseso Urine, lungs, sweat and leces- Recommendationso Needs vary, fever, out in the heat, exerciseo AI for total water, includes the water you get from fruits and vego 8 or 12 cups a day- Health Effectso Meet bodily needso Protects against urinary stones and constipationo Concentration, alertness and short-term memoryBlood Volume and Blood Pressure- Kidneys are central to blood volumes and pressure maintenance- Antidiuretic hormone (ADH)o Produced by pituitary glando Water conserving hormone Stimulates kidneys to reabsorb water- Renino Enzyme released by kidney cells when blood pressure is lowo Kidneys reabsorb sodium Water retention, with more water in blood, more volume so bp is gonna go up- Angiotensino Renin hydrolyzes angiotensinogen to angiotensin I Convert to active form- angiotensin 2- Aldosteroneo Released from adrenal glands Release stimulated by angiotensin 2o Signals kidneys Excrete potassium Retain sodium and thus water- FLUID AND ELECTROLYTE BALANCEo Water follows electrolytes Electrolytes predominately outside of cell Na,Clo Electrolytes predom inside cello K, Mg, Ph, S- Proteins regulate fluid movemento Attract watero Transport proteins Passage of ions across cell membranes Sodium potassium pumpo Regulation of fluid and electrolyte balance Two sites- Gi tract- Kidneys- Causes of imbalanceo Prolonged vomiting or diarrheao Heavy sweatingo Burnso Traumatic woundso Some medications- Replacing lost fluids and electrolyteso Plain cool water and regular foodso Special replacement fluid oral replacement Therapy= water sugar and salt - THE MINERALSo Major vs. trace minerals Variation amounts neededo Inorganic elements Always retain chemical identity Not destroyed by heat, air acid or mixing- Sodium, Potassium, Chlorideo Helps maintain bod fluids *one question on each of these- Calcium, Phosphorous, Magnesiumo Bone growth and health- SODIUMo Roles in body Principal cation of extracellular fluid- Primary regulator of volume Acid base balance Nerve impulse transmission Muscle contractiono Kidneys: filter out and return what is neededo Reccomendations Average intake in U.S exceeds the ULo Hypertension Salt intake-attracts water into blood so higher volume and pressure DASH diet-dietary approach to stop hypertension- Low in sodium, high in potassium (fruits and veg), high in calcium dairy, lean meats, whole grainso Bone Loss (osteoporosis) High slat intake is associated with increased calcium excretion- Potassium as protective factor DASH diet recommendationo Food Sources Processed foods are not good- More sodium- Less potassiumo Deficiency=hyponatremiao Toxicity Actue-edema and high bp Chronic-hypertension- CHLORIDEo Roles in body Major anion of extracellular fluids Fluid and electrolyte balance Part of hydrochloric acid (HCL)o Deficiency and toxicity rareo Abundant In processed foods- POTASSIUMo Principal intracellular cationo Roles in body Help maintain fluid and electrolyte balance Maintain cell integrity Aids in nerve impulse transmission and muscle contractiono Recommendations and intakes Fresh foods=richest sources- Increase fruit and veg intake to meet AIo Hypertension Diets low in potassium-increase BP Diets high in potassium-lower BP and risk of strokeo Deficiency Increase BP,muscle weakness, salt sensitivityo Toxicity No UL Too many K salts or supplements but not from diet Kidneys accelerate excretion- CALCIUMo Most abundant mineral in the bodyo Adequate intake Grows a healthy skeleton in early life Helps minimize bone loss in later lifeo Majority of bodys calcium is in bones and teeth 99% Part of bone structure Calcium banko In bones Calcium salts form crystals- Hydroxyapatite Strength and rigidity to maturing bones Bone remodelingo In teeth Fluoride stabilizes calcium crystals in teetho In body fluids Helps maintain normal bp Extracellular calcium- Participates in blood clotting Intracellular calcium- Regulation of muscle contraction- Transmission of nerve impulses- Secretion of hormones- Activation of some enzyme reactions Disease prevention- HTN,chol,DM,colon CA Obesity- May help maintain healthy body weighto Inverse relationship with food sources Calcium balance- Involves system of hormonses and vitamin d*vit d enhances calcium eabsorptiono Parathyroid hormone and calcitonin- Organ system responseo Intestineso Boneso Kidneyso Absorption 30% in adults efficiency and inadequate intakeso recommendations based on amount needed to retain calcium in bones peak bone mass adverse effects from supplementso milk products most abundant conceal milk products in foods other foods: bioavailability fortified juice and foodso calcium and irono deficiency peak bone mass by late 20s all adults lose bone with age- begins 30-40 years old osteoporosis- silent
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