Chapter 8 Minerals and Water 2012 Pearson Education Inc Objectives for Chapter 8 Explain the functions of water in the body Describe the daily recommended intake for water consumption Describe the difference between dehydration and water intoxication List at least one food source for each major mineral Identify the role of sodium in your body Name at least three lifestyle habits that can increase the risk for high blood pressure Describe osteoporosis and the factors that influence the risk of developing the disease List at least one major food source for each trace mineral Compare and contrast heme and nonheme iron Explain the role of fluoride in tooth and bone structure Nutrition and You 2e 2012 Pearson Education Inc Why Is Water So Important Water is the most abundant substance in body Average healthy adult is about 60 percent water Muscle 65 percent water fat 10 to 40 percent water Can only survive a few days without water Water balanced among fluid compartments Intracellular fluids inside cells Extracellular fluids interstitial fluid between cells and fluid in the blood Electrolytes minerals that help maintain fluid balance Nutrition and You 2e 2012 Pearson Education Inc Animation Roles of Electrolytes in Water Balance Nutrition and You 2e 2012 Pearson Education Inc What Does Water Do in Your Body Acts as universal solvent and a transport medium Medium for many chemical reactions in body As part of blood helps transport oxygen nutrients hormones to cells As part of interstitial fluid helps transport waste products away from cells for excretion Helps maintain body temperature Is a lubricant for joints eyes and is part of mucus and saliva Is a protective cushion for brain organs fetus Nutrition and You 2e 2012 Pearson Education Inc Think Before You Drink Can Water Boost Your Brain Nutrition and You 2e 2012 Pearson Education Inc Think Before You Drink Can Water Boost Your Brain Discussion Questions What is enhanced water What are some false claims of enhanced water Are enhanced waters healthy beverages to consume Nutrition and You 2e 2012 Pearson Education Inc Your Body is Mostly Water Figure 8 1 Nutrition and You 2e 2012 Pearson Education Inc Water as Part of Body Fluids Figure 8 2 Nutrition and You 2e 2012 Pearson Education Inc Water Helps Regulate Your Body Temperature Figure 8 3 Nutrition and You 2e 2012 Pearson Education Inc What Is Water Balance and How Do You Maintain It Water balance water consumed water lost You take in water through beverages and food You lose water through your kidneys as urine large intestine lungs and skin as sweat Insensible water loss through evaporation from skin and when you exhale Losing too much water can cause dehydration Dehydration can result from inadequate water intake or too much water loss from diarrhea vomiting high fever or use of diuretics Nutrition and You 2e 2012 Pearson Education Inc Losing Too Much Water Can Cause Dehydration Dehydration can result from inadequate water intake or too much water loss from diarrhea vomiting high fever or use of diuretics Your thirst mechanism signals dehydration Dry mouth due to increased electrolyte concentration in blood less water available to make saliva Blood volume decreases sodium concentration increases in blood Brain triggers thirst mechanism and secretion of antidiuretic hormone ADH to reduce urine output Fluid inside cells moves into blood by osmosis Nutrition and You 2e 2012 Pearson Education Inc Animation Water Balance Nutrition and You 2e 2012 Pearson Education Inc The Concept of Water Balance Intake Equals Output Figure 8 4 Nutrition and You 2e 2012 Pearson Education Inc Osmosis Figure 8 5 Nutrition and You 2e 2012 Pearson Education Inc Urine Color Can Signal Dehydration Figure 8 6 Nutrition and You 2e 2012 Pearson Education Inc Consuming Too Much Water Can Cause Hyponatremia Hyponatremia is a condition of too little sodium in the blood For healthy individuals who consume a balanced diet it is difficult to consume too much water However some individuals have experienced water toxicity Nutrition and You 2e 2012 Pearson Education Inc How Much Water Do You Need and What Are the Best Sources Daily water needs vary depending on physical activity environmental factors and diet Recommendations based on reported total water intake of healthy Americans Men 16 cups day about 13 cups of beverages Women 12 cups day about 9 cups of beverages About 80 percent from beverages 20 percent from foods Physical activity increases needs Nutrition and You 2e 2012 Pearson Education Inc ABC News Drinking Water How Much to Drink Nutrition and You 2e 2012 Pearson Education Inc ABC News Drinking Water How Much to Drink Discussion Questions How many glasses of fluids should an adult woman drink each day An adult man Where do we get 20 percent of the water we consume each day What scientific evidence exists for the belief that water helps the kidneys remove toxins from the body Nutrition and You 2e 2012 Pearson Education Inc Water Content of Foods Figure 8 7 Nutrition and You 2e 2012 Pearson Education Inc The Best Way to Meet Your Daily Water Needs Figure 8 8 Nutrition and You 2e 2012 Pearson Education Inc What Are Minerals and Why Do You Need Them Inorganic elements needed in relatively small amounts Minerals have varying bioavailability Some minerals compete for absorption too much of one can decrease absorption of another Example Excess zinc can reduce copper absorption Some substances bind minerals making them unavailable for absorption Example Oxalates in spinach bind calcium Nutrition and You 2e 2012 Pearson Education Inc What Are Minerals and Why Do You Need Them Major minerals macrominerals needed in amounts 100 g day Trace minerals microminerals needed in amounts 20 g day You need major minerals in larger amounts Sodium chloride potassium magnesium sulfur play key roles in fluid balance Calcium phosphorus magnesium work together to strengthen bones and teeth Nutrition and You 2e 2012 Pearson Education Inc What Are Minerals and Why Do You Need Them Trace minerals microminerals are needed in small amounts 20 g day Present even in smaller amounts in body However play essential roles as important as major minerals Chromium and iodine help certain hormones Iron maintains healthy red blood cells Fluoride protects teeth Iron zinc copper manganese and molybdenum are cofactors that work with enzymes in critical chemical reactions Nutrition and You 2e 2012 Pearson Education Inc The Minerals in Your Body Figure 8