Chapter 8 Water and Minerals Nutrition: Concepts & Controversies, 12e Sizer/Whitney

Learning Objectives Identify the best beverage choices to obtain enough water for the body’s needs. Describe the body’s water sources and routes of water loss, and name factors that influence the need or water. Compare and contrast various sources of drinking water for safety.

Learning Objectives Discuss why electrolyte balance is critical for the health of the body. Describe the nutrients needed to maintain blood calcium levels, and explain why this is important. Describe a diet that follows the DASH principles, and specify who might benefit from such a diet and in what ways.

Learning Objectives Compare the availability of iron form plant and animal sources. Discuss the function and importance of copper, zinc, chromium, fluoride, and selenium in the body. Describe a diet that a young woman can follow to help prevent osteoporosis later in life.

Introduction Minerals Major Trace Water Most indispensable nutrient

Minerals in a 60-Kilogram (132-Pound) Person (Grams)

Water Makes up about 60 percent of a person’s weight Roles Solvent Cleansing agent Lubrication and cushion Coolant

Body’s Water Balance Water balance Body water varies by pounds Dehydration Thirst Signs Groups at risk Water intoxication Body water varies by pounds Thirst and satiety govern water intake Hypothalamus, pituitary gland, kidneys

Water Balance – A Typical Example

Effects of Mild Dehydration, Severe Dehydration, and Chronic Lack of Fluid

How Much Water Do I Need to Drink in a Day? Water needs vary Influential factors Fluids and foods DRI Metabolic water Sweating Choosing fluids Caffeine

U.S. Fluid Sources

Are Some Kinds of Water Better for My Health Than Others? Types of water Hard Calcium and magnesium Soft Sodium Hypertension

Safety and Sources of Drinking Water Public water Removal of many hazards Disinfectants Testing and reporting Chlorination and cancer Water sources Surface water Groundwater

Bottled Water Regulation and safety BPA IBWA trademark Sales across state lines Standards Less rigid than those for tap water BPA IBWA trademark Water for nutrition’s sake Fluoride

Body Fluids and Minerals Water follows salt Electrolytes Water flows toward greater concentration Fluid and electrolyte balance Causes of imbalance Acid-base balance Hydrogen Buffers

How Electrolytes Govern Water Flow

Calcium Most abundant mineral in the body Meeting DRI recommendations Storage facilities Bones In constant flux Teeth

A Bone

Calcium Bone and tooth formation Hydroxyapatite Fluorapatite Bone and tooth turnover

Calcium In body fluids Calcium balance 1 percent of body’s calcium Roles Blood calcium is tightly controlled Calcium balance Skeleton serves as a calcium bank Bone density Organs

Calcium Bone loss Calcium absorption Recommendations Inevitable consequence of aging Peak bone mass Osteoporosis Supplements Calcium absorption Increases in times of need Recommendations

Bone Throughout Life

Calcium Snapshot

Phosphorus Second most abundant mineral in body Roles in the body Majority found in bones with calcium Roles in the body Recommendations Deficiencies are unlikely Food sources

Phosphorus Snapshot

Magnesium “Major mineral” Bones and kidneys Roles in the body Dietary requirement Bones and kidneys Roles in the body Works with calcium Deficiency Toxicity Recommendations

Magnesium Snapshot

Sodium Roles Deficiency “Water Weight” Recommendations Major part of fluid and electrolyte balance Acid-base balance Deficiency “Water Weight” Recommendations Intakes

Sodium and Salt Intake Guidelines

Sodium Blood pressure Controlling salt intakes Hypertension Measures Types Sodium intakes increases blood pressure Heart damage DASH diet Controlling salt intakes

How to Cut Sodium from a Barbeque Lunch

Potassium Positively charge ion inside the cells Roles Deficiency Fluid and electrolyte balance Heartbeat Deficiency Dehydration Toxicity Recommendations

Potassium Snapshot

Chloride and Sulfate Chloride Sulfate Crucial for fluid balance Hydrochloric acid Principle food source Sulfate Roles No recommended intake Deficiencies are unknown

Trace Minerals

Iodine Body’s work is done by iodide Roles Deficiency Toxicity Thyroxine Deficiency Goiter Cretinism Toxicity Food sources

Iron Every living cell contains iron Two proteins Roles Hemoglobin Myoglobin Roles Carry oxygen Make new cells, amino acids, hormones, & neurotransmitters

Iron Iron stores Absorbing iron A mineral to be hoarded Iron losses Special proteins transport and store iron Absorbing iron Forms of iron in food MFP factor Impairing iron absorption

Iron Deficiency Iron deficiency Iron-deficiency anemia Signs of deficiency Mental symptoms Adults Children Pica

Normal and Anemic Blood Cells

Iron Causes of deficiency Groups most susceptible to deficiency Women of childbearing age Infants and toddlers Adolescents Too much iron Iron overload Symptoms

Iron Snapshot

Zinc Works with proteins in every organ Expression of deficiency Roles Expression of deficiency Groups at greatest risk for deficiency Vegetarians

Zinc Snapshot

Selenium Roles in the body Relationship with chronic disease Toxicity Cancer Toxicity Supplements Sources

Fluoride Not essential to life Roles in the body Deficiency Toxicity Dental decay Toxicity Fluorosis Sources

U.S. Population with Access to Fluoridated Water Through Public Water Systems

Chromium and Copper Chromium Copper Roles in the body Recommendation Sources Copper Deficiency Toxicity

Other Trace Minerals and Some Candidates Molybdenum Manganese Boron Cobalt Nickel Silicon All trace minerals are toxic in excess!

Meeting the Need for Calcium Low calcium intake Associated diseases Milk, yogurt, & cheese group Traditional sources of calcium

Food Sources of Calcium in the U.S. Diet

Meeting the Need for Calcium Vegetables Absorption Calcium binders Other foods Calcium-fortified foods Supplements Making meals rich in calcium

Calcium Absorption from Food Sources

Osteoporosis: Can Lifestyle Choices Reduce the Risks? Controversy 8

Introduction Osteoporosis prevalence Causes Fractures Sex differences Tangled complexity

Development of Osteoporosis Bone Trabecular Tapped when blood calcium is low Cortical Decline in bone density Dowager’s hump Fractures Common sites

Losses of Trabecular Bone

Loss of Height in a Woman Caused by Osteoporosis

Toward Prevention – Understanding the Cause of Osteoporosis Causes Gender and advanced age Genetics and environmental factors Bone density and genes Influence of genes Genetic inheritance Risks vary by race and ethnicity

Toward Prevention – Understanding the Cause of Osteoporosis Calcium and vitamin D Bone strength in later life Bone building during childhood and adolescence Gender and hormones Menopause for women Estrogen and testosterone Body weight

Toward Prevention – Understanding the Cause of Osteoporosis Physical activity Tobacco smoke and alcohol Protein Too little protein Too much protein Sources Sodium, caffeine, soft drinks Other nutrients

Risk and Protective Factors That Correlate with Osteoporosis

Diagnosis and Medical Treatment DEXA scan Drug therapies Estrogen replacement therapy

Calcium Recommendations Recommendations vary Set according to life stage Sources Foods and beverages first Dietary calcium Sunshine for vitamin D Supplements Types of supplements