Chapter 9 - WAter and minerals

What percentage of the human body is water?

Approximately 50–70%; water is essential for every cell, tissue, and organ.

What are the three sources of water intake?

Beverages, foods, and metabolic water produced during chemical reactions.

What are the four major routes of water loss?

Urine, perspiration (skin), respiration (lungs), and feces.

What is the difference between sensible and insensible water loss?

Sensible water loss can be measured, primarily through urine; insensible water loss occurs through skin and respiration.

What hormones regulate fluid balance?

ADH, angiotensin, and aldosterone help regulate water retention, blood volume, and blood pressure.

What does antidiuretic hormone (ADH) do?

Signals the kidneys to retain water, increasing blood volume; it can also constrict blood vessels and raise blood pressure.

What does aldosterone do?

Signals the kidneys to retain sodium; water follows sodium through osmosis, increasing blood volume.

What are the five major functions of water?

Dissolves substances, transports nutrients and wastes, supports chemical reactions, regulates body temperature, and lubricates and cushions tissues.

How does water regulate body temperature?

Sweat evaporates from the skin, releasing heat and cooling the body.

What is the difference between hard and soft water?

Hard water contains more calcium and magnesium; soft water contains fewer dissolved minerals and may contain more sodium.

What are the four types of bottled water?

Artesian water comes from a confined aquifer; spring water flows naturally to the surface; mineral water comes from mineral-rich groundwater; purified water undergoes treatment such as distillation or reverse osmosis.

What causes dehydration, and what are its consequences?

Excessive water loss or inadequate intake causes dehydration, which can impair physical and mental function; severe dehydration can cause kidney failure, coma, and death.

What are two major health risks associated with dehydration?

Heat exhaustion or heat stroke and increased risk of kidney stone formation.

What does urine color indicate about hydration?

Pale yellow or straw-colored urine generally indicates adequate hydration; darker urine may indicate dehydration, although foods, vitamins, and medications can affect color.

What is hyponatremia (water intoxication)?

An abnormally low blood sodium concentration, often caused by excessive water intake, which can cause cells to swell.

What are symptoms of severe hyponatremia?

Nausea, vomiting, muscle cramps, confusion, headaches, seizures, coma, and potentially death.

What is the difference between minerals and vitamins?

Minerals are inorganic chemical elements that cannot be broken down further; vitamins are organic compounds.

What is the difference between major and trace minerals?

Major minerals are needed in amounts greater than 100 mg daily; trace minerals are needed in amounts less than 100 mg daily.

What are the six major minerals emphasized in Chapter 9?

Sodium, potassium, chloride, calcium, phosphorus, and magnesium.

What are the major trace minerals emphasized in Chapter 9?

Iron, zinc, selenium, iodine, copper, and fluoride.

What is mineral bioavailability?

The body's ability to absorb and use a mineral from food.

What factors affect mineral absorption?

Age, sex, nutritional status, genetics, medications, dietary fiber, phytates, oxalates, and interactions with other minerals and vitamins.

How do phytates and oxalates affect mineral absorption?

They bind minerals and reduce their absorption and bioavailability.

How do vitamins C and D improve mineral absorption?

Vitamin C increases iron absorption; vitamin D increases calcium absorption.

What is mineral toxicity?

A harmful condition caused by consuming excessive amounts of a mineral, often exceeding its tolerable upper intake level (UL).

How can minerals be preserved in foods?

Avoid excessive processing, refining, and milling of plant foods because these processes can remove minerals; enrichment may replace only selected nutrients.

What is osmosis?

The passive movement of water across a semipermeable membrane from an area of lower solute concentration toward an area of higher solute concentration.

What are intracellular and extracellular fluids?

Intracellular fluid (ICF) is fluid inside cells and contains approximately 63% of body water; extracellular fluid (ECF) is outside cells and contains approximately 37%.

What are electrolytes?

Minerals that dissolve in water and carry an electrical charge, helping regulate fluid balance, nerve transmission, and muscle contraction.

Where are sodium and potassium primarily located?

Sodium is the major positively charged ion outside cells; potassium is the major positively charged ion inside cells.

What are the three major functions of sodium?

Regulates extracellular fluid balance, helps transmit nerve impulses, and supports muscle contraction.

What is the main dietary source of sodium?

Table salt (sodium chloride); processed and restaurant foods also contribute substantial amounts.

How much sodium is in one teaspoon of table salt?

Approximately 2,400 mg of sodium.

What percentage of table salt is sodium and chloride by weight?

Approximately 40% sodium and 60% chloride.

What is the recommended sodium reduction threshold for adults 14 and older?

The Chronic Disease Risk Reduction recommendation is to reduce sodium intake when it exceeds 2,300 mg per day.

What is hyponatremia, and what can cause it?

Low blood sodium concentration, potentially caused by excessive water intake, prolonged sweating, vomiting, or diarrhea.

What is hyperkalemia?

An abnormally high blood potassium concentration that can cause dangerous heart rhythm disturbances, especially with impaired kidney function.

What are the three major functions of potassium?

Regulates intracellular fluid balance, supports nerve impulse transmission, and enables muscle contraction.

How does potassium affect blood pressure?

Higher potassium intake is associated with lower blood pressure and helps counterbalance the effects of sodium.

What are good dietary sources of potassium?

Potatoes, fruits, vegetables, beans, lentils, milk, whole grains, meat, and fish.

What is hypokalemia, and what are its symptoms?

Low blood potassium; symptoms include muscle cramps, weakness, constipation, confusion, and potentially fatal irregular heartbeat.

What are common causes of potassium deficiency?

Chronic vomiting, diarrhea, inadequate intake, laxative use, and potassium-wasting diuretics.

What are the major functions of chloride?

Regulates fluid balance, maintains acid-base balance, supports nerve transmission, and forms hydrochloric acid in the stomach.

What is the main dietary source of chloride?

Table salt (sodium chloride), which is approximately 60% chloride by weight.

What are the three major functions of calcium?

Builds and maintains bones and teeth, supports muscle contraction and nerve signaling, and helps blood clot.

Where is most of the body's calcium stored?

Approximately 99% is stored in bones and teeth, primarily as hydroxyapatite.

What improves calcium absorption?

Vitamin D, stomach acidity, and lactose can improve calcium absorption.

What decreases calcium absorption?

Oxalates, phytates, tannins, vitamin D deficiency, and certain medications and gastrointestinal conditions.

What are good dietary sources of calcium?

Milk, yogurt, cheese, sardines, salmon with bones, and fortified foods.

What happens when blood calcium levels become too low?

Parathyroid hormone stimulates bones to release calcium, kidneys to retain calcium, and intestines to increase calcium absorption.

What is tetany?

Involuntary muscle stiffness, twitching, or inability to relax muscles, which can occur with low blood calcium.

What is osteoporosis, and how can its risk be reduced?

A condition characterized by decreased bone mass and increased fracture risk; prevention includes adequate calcium and vitamin D, weight-bearing exercise, resistance training, and avoiding smoking and excessive alcohol.

What are the consequences of excessive calcium intake?

Potential kidney stones, soft tissue calcification, impaired absorption of other minerals, and elevated blood calcium.

What are the major functions of phosphorus?

Builds bones and teeth, forms DNA and RNA, contributes to ATP production, supports cell membranes, and helps maintain acid-base balance.

What are good dietary sources of phosphorus?

Milk, cheese, meat, eggs, fish, nuts, whole grains, and some processed foods.

What can excessive phosphorus intake contribute to?

Soft tissue mineralization, kidney complications, and bone loss, particularly when calcium intake is inadequate.

What are the major functions of magnesium?

Supports bone structure, activates hundreds of enzymes, assists ATP production, supports DNA and protein synthesis, and helps regulate muscle and nerve function.

What are good dietary sources of magnesium?

Nuts, seeds, beans, whole grains, leafy greens, broccoli, and some animal foods.

What are symptoms of magnesium deficiency?

Muscle weakness, muscle pain, irregular heartbeat, disorientation, seizures, and impaired calcium metabolism.

What are common causes of magnesium deficiency?

Kidney disorders, alcohol use disorders, malabsorption, prolonged vomiting or diarrhea, heavy sweating, and certain medications.

What are the major functions of iron?

Forms hemoglobin and myoglobin, transports oxygen, supports energy production, and contributes to brain and immune function.

What is the difference between heme and non-heme iron?

Heme iron comes from animal foods and is absorbed more efficiently; non-heme iron comes from plant and fortified foods and is less efficiently absorbed.

What improves and inhibits non-heme iron absorption?

Vitamin C and stomach acidity improve absorption; phytates, oxalates, tannins, and competing mineral supplements inhibit absorption.

What are good dietary sources of iron?

Red meat, poultry, fish, beans, lentils, and iron-fortified cereals.

What is iron-deficiency anemia?

A condition caused by inadequate iron that results in smaller, paler red blood cells with reduced oxygen-carrying capacity.

What are symptoms and risk factors of iron-deficiency anemia?

Fatigue, pale skin, weakness, poor temperature regulation, and reduced immunity; risks include menstruation, pregnancy, rapid growth, blood loss, and low dietary iron.

What is hemochromatosis?

A genetic disorder causing excessive iron absorption and storage, potentially damaging the liver, heart, pancreas, and other organs.

What are the major functions of zinc?

Supports immune function, DNA synthesis, protein metabolism, growth, wound healing, and enzyme activity.

What are good dietary sources of zinc?

Meat, seafood, poultry, dairy products, and fortified cereals.

What are symptoms of zinc deficiency?

Delayed wound healing, impaired immunity, hair loss, diarrhea, reduced taste and smell, and impaired growth and sexual development in children.

What can excessive zinc supplementation cause?

Nausea, vomiting, diarrhea, reduced immune function, and copper deficiency due to impaired copper absorption.

What are the major functions of selenium?

Supports antioxidant defenses through glutathione peroxidase, helps preserve vitamin E, and supports thyroid hormone metabolism.

What are good dietary sources of selenium?

Seafood, meat, eggs, Brazil nuts, grains, and seeds; selenium content depends partly on soil.

What are symptoms of selenium deficiency and toxicity?

Deficiency can cause muscle wasting, heart damage, and impaired thyroid function; toxicity can cause hair loss, weakness, nausea, vomiting, and liver damage.

What are the major functions of iodine?

Required to produce thyroid hormones, regulate metabolic rate, and support normal growth and brain development.

What are good dietary sources of iodine?

Iodized salt, seafood, seaweed, dairy products, and some grain products.

What is goiter, and what causes it?

An enlargement of the thyroid gland that can develop when iodine intake is inadequate.

What are the consequences of iodine deficiency during pregnancy?

Can cause congenital hypothyroidism and impaired brain development, potentially resulting in learning, speech, and developmental problems.

What are the major functions of copper?

Supports iron metabolism and hemoglobin formation, antioxidant enzymes, connective tissue formation, energy production, and nervous system function.

What are good dietary sources of copper?

Organ meats, shellfish, nuts, seeds, whole grains, and cocoa.

What are symptoms of copper deficiency and toxicity?

Deficiency can cause anemia, weakened immunity, poor growth, and bone loss; toxicity can cause gastrointestinal distress and liver and kidney damage.

What is fluoride's proposed benefit and major toxicity?

Fluoride can strengthen tooth enamel and reduce dental cavities; excessive exposure can cause dental fluorosis, including permanent enamel discoloration and pitting.

What is chromium's proposed function, and what is known about deficiency?

Chromium may enhance insulin function and glucose metabolism; deficiency is rare but may impair blood glucose control.

What are the functions of manganese and molybdenum?

Manganese supports enzyme activity, antioxidant defenses, and bone formation; molybdenum supports enzymes involved in sulfur-containing amino acid metabolism.

What is hypertension, and how is blood pressure classified?

Hypertension is persistently elevated blood pressure. Normal is below 120/80 mm Hg; elevated is systolic 120–129 with diastolic below 80; stage 1 is 130–139 or 80–89; stage 2 is 140 or higher or 90 or higher.

What are major risk factors and strategies for reducing hypertension?

Risk factors include genetics, age, inactivity, obesity, excess alcohol, and certain dietary patterns. Strategies include regular exercise, a balanced diet rich in potassium, calcium, and magnesium, limiting excessive sodium, maintaining a healthy weight, and moderating alcohol.