nutrition chapter 9 - water and minerals
The degree to which a substance becomes available to the target tissue.
Define bioavailability..
Ultratrace mineral
A mineral present in the human diet in trace amounts but that has not been shown to be essential to human health
77
About ...% of the sodium we consume is added in the form of salt during food manufacturing and food preparation at restaurants.
Sodium ions
... also function in nerve impulse conduction and absorption of some nutrients (e.g., glucose)
Water-based secretions, Saliva, Mucus, cerebrospinal, amniotic
... are produced by the digestive tract, respiratory tract, urogenital tract, eyes, and skin. ... acts as a lubricant, allowing food to pass through the esophagus to the stomach. ... provides a protective fluid coating throughout the digestive tract. The lungs are coated with a layer of mucus that provides an important immunologic function. Water helps form the lubricant found in knees and other joints of the body. The spinal cord and brain are cushioned by .... fluid. Water is also the basis of ... fluid, which functions as a shock absorber surrounding the growing fetus in the mother's womb.
Oxalates, tannins, Phytates
... found in sweet potatoes, collard greens, spinach, and rhubarb Tea and some legumes are rich sources of ... ... found in whole grains, raw beans, and nuts
Chloride
... ions are also a component of the acid produced in the stomach (hydrochloric acid) and are important for overall maintenance of acid-base balance in the body. This electrolyte is used during immune responses as white blood cells attack foreign cells. In addition, nervous system function relies on the presence of this
Perspiration
... is the primary way to prevent rise in body temperature.
Potassium (K)
... performs many of the same functions as sodium, such as water balance and nerve impulse transmission.
Calcium
... represents 40% of all the minerals present in the body and equals about 2.5 pounds (1200 grams) in the average person. All cells require this to function; however, more than 99% of the this in the body is used for growth, development, and maintenance of bones. This is the main component of hydroxyapatite, the crystalline compound responsible for the structure and hardness of bone.
Aids in immune function (but Intakes >RDA do not provide additional benefit for immune function) Plays a role in taste Plays a beneficial role in wound healing
3 functions of zinc?
seaweed, Salt
A few fruits and vegetables, such as ..., celery, tomatoes, and olives, are naturally good sources of chloride. Most of our dietary chloride, however, comes from ... added to foods. this is 60% chloride by weight, so knowing a food's salt content allows for a close prediction of its chloride content.
infancy, pregnancy, vitamin D
Adults absorb about 30% of the calcium in the foods eaten, but during times when the body needs extra calcium, such as in ... and ..., absorption increases to as high as 60%. Aging negatively influences the absorption efficiency of calcium; due to decreased acid secretion in the stomach and lower synthesis, absorption, and activation of ..., people over age 40 have a harder time meeting their needs for calcium.
90
Approximately ..% of the potassium consumed is absorbed
osteoporosis
Approximately 12 million Americans >50 currently have ...
Essential for blood clot formation Muscle contraction is activated by calcium release
Beyond its role in bone health, what are some other critical functions of calcium?
kyphosis
Both men and women can develop a curvature in the upper spine called ... or dowager's hump. This is a major concern because the bending of the spine may decrease the volume of the chest cavity, resulting in difficulty breathing, abdominal pain, decreased appetite, and premature satiety
kidney, decreased, kidneys, excreted
If blood sodium is low, as blood flows through the ..., sodium is secreted back into the blood, resulting in a ... urine output. Conversely, if our blood sodium levels are too high, the sodium is filtered out by the ... and ... into the urine.
toxicity, Upper Level
If the kidneys function normally, potassium from dietary sources will not lead to .... Thus, no ... for potassium has been set.
fruit, vegetable
In fact, North Americans typically consume only 2000 to 3000 milligrams of potassium per day, much less than the AI. Thus, many of us need to increase potassium intake, preferably by increasing ... and ... intake.
Uncommon due to widespread availability in food Potentially seen in starvation, hormonal imbalance or medications
Is phosphorus deficiency very common, or is the RDA met by most North Americans?
1000, 1200
RDA for calcium is ... milligrams per day for adults through 50 years of age Women older than age 50, and men and women over age 70, RDA is ... milligrams per day
potassium, magnesium, zinc
Some people take diuretics to lower their blood pressure. Diuretics cause the kidneys to excrete more urine but at the same time may increase urinary excretion of minerals. This is nutritionally relevant for regulation of blood levels of ..., ..., and ....
15, 11
What is the AI for fluid intake for adult men? For adult women?
copper
a large intake of zinc decreases ... absorption
deficiency of chloride
disturbance of the body's acid-base balance unlikely because dietary NaCl intake is high
grains
food source providing these minerals
protein
food source providing these minerals
vegetables
food source providing these minerals
hypertonic, hypotonic
if the intracellular concentration of electrolytes is greater than the extracellular concentration—that is, ...—water will flow freely into the cell. If too much water flows in, the cell can burst, similar to filling a balloon with too much air. The opposite can also occur. When the intracellular concentration of electrolytes is relatively low or ... compared to the extracellular environment, water will exit the cell, leading to cell shrinkage.
muscle contraction and relaxation
sodium, chloride, potassium, calcium, magnesium
sodium sensitive, African Americans, Asian Americans, hypertension
approximately 10% to 15% of adults are ...; that is, sodium intake has a direct effect on their blood pressure. As their sodium intake increases, so does their blood pressure. Among these people, lower-sodium diets (about 2000 milligrams daily) often decrease blood pressure. Groups that appear to be especially affected are ..., ..., and people who have diabetes and/or are overweight. Lifestyle factors such as being overweight and inactive are the major contributors to the development of ...
spinach, dairy, tofu
calcium can be found in ....
bone health
calcium, phosphorus, iron, zinc, copper, fluoride, manganese
growth and development
calcium, phosphorus, zinc
dairy
food source providing these minerals
fruits
food source providing these minerals
Part of hemoglobin in red blood cells and myoglobin in muscle cells Hemoglobin transports oxygen from lungs to cells, removes carbon dioxide from cells to lungs Used as part of many enzymes, proteins and compounds in energy production Needed for brain and immune function, drug detoxification in liver, synthesis of collagen in bone
functions of iron?
blood health
iron, copper, calcium, zinc
zinc
large intake of ... decreases copper absorption
body defenses
magnesium, iron, selenium, zinc, copper, manganese
symptoms of sodium deficiency
muscle cramps, nausea, vomiting, dizziness, and later shock and coma
fluid portion of blood (plasma) and lymph, the fluid between cells (interstitial)
remaining body fluid besides the intracellular fluid is found outside of cells in one of two extracellular spaces: (1) the ...., accounting for 7% of body fluid; or (2) ..., making up 30% of body fluid
nerve impulses
sodium, potassium, chloride, calcium
fluid and electrolyte balance
sodium, potassium, chloride, phosphorus, water
kidneys, angiotensin, aldosterone, sodium
the ... possess receptors that monitor blood pressure. Low blood pressure triggers the release of an enzyme that activates ... and, eventually, ..., two hormones that signal the kidneys to retain more ... and, in turn, more water via osmosis. As sodium and water are retained, blood pressure increases back to normal.
thiamin
without magnesium or manganese, the ... coenzyme cannot function efficiently.
Incorporated into tooth structure, which increases strength and resistance to acid degradation from plaque Stimulates remineralization of enamel Provides antibacterial effect
How does fluoride help to reduce the development of dental caries?
Aids antioxidant enzyme glutathione peroxidase Spares vitamin E
How does selenium play an antioxidant role?
high chloride results in higher blood pressure
How is chloride intake related to blood pressure?
Enhances insulin uptake of glucose into cells
How is chromium involved in carbohydrate metabolism?
Higher potassium intake is associated with lower blood pressure
How is potassium intake related to blood pressure?
laxatives, diuretics, eating disorders, alcohol use, potassium rich foods
Hypokalemia can result from continually deficient food intake, but it is most commonly seen with chronic diarrhea or vomiting, or as a side effect of medications, including ... and some .... Vulnerable populations include people with certain ... or ... disorders. Other populations at increased risk for potassium deficiency include people on very low-calorie diets and athletes who exercise for prolonged periods. These people should compensate for potentially low body potassium by consuming ....
tetany
If blood calcium does fall below a critical point, muscles cannot relax after contraction and nerve function is disrupted. The result is a condition called ..., in which muscles become stiff or twitch involuntarily.
hyponatremia
If water intake far exceeds the kidneys' processing ability, overhydration and sodium dilution in the blood result. This condition is commonly known as water intoxication, or more accurately, .... Water intoxication can happen to healthy people when they drink a great deal of water in a very short period of time. Endurance athletes exercising for prolonged times, drinking large volumes of water to replace sweat losses, are especially at risk. Rapid dilution of the blood causes tissues to swell. The heartbeat becomes irregular, allowing fluid to enter the lungs; the brain and nerves swell, causing severe headaches, confusion, seizure, and coma.
potassium, blood pressure
Intracellular fluids contain 95% of the ... in the body. Higher intake is associated with lower rather than higher ... values.
acid base balance, bulimia, gastroenteritis, diuretics, laxatives
Low levels of chloride in the blood can lead to a disturbance of the body's .... A chloride deficiency is unlikely, however, because our dietary salt intake is so high. Frequent and lengthy bouts of vomiting, if coupled with a nutrient-poor diet, can contribute to a deficiency because stomach secretions contain a lot of chloride. Therefore, individuals with ... or severe cases of ... are at risk for chloride deficiency. In addition, low chloride levels could occur as a side effect of some medications, such as ... or ....
potassium
Major contributors of .... to the adult diet include milk, potatoes, beef, coffee, tomatoes, and orange juice.
major mineral, Trace minerals
Minerals are categorized based on the amount we need per day. Recall from Chapter 1 that if we require greater than 100 milligrams (1/50 of a teaspoon) of a mineral per day, it is considered a .... These include calcium, phosphorus, magnesium, sulfur, sodium, potassium, and chloride. ... are required at levels less than 100 milligrams per day. Nine essential trace minerals (iron, zinc, copper, iodide, selenium, molybdenum, fluoride, manganese, and chromium) have been identified for humans.
milk
Most unprocessed foods are relatively low in sodium; ... is one exception (about 120 milligrams per cup).
digestive tract, concentration, actively
Nearly all the sodium we consume is absorbed by the .... When sodium chloride (NaCl) is dissolved in water, the chemical bond holding the two atoms together breaks and the charged ions Na+ and Cl− are released. These electrolytes, as well as others, attract water. The concentration of intracellular and extracellular water is controlled by the ... of the electrolytes. Fluid balance is maintained by moving or ... pumping sodium ions where more water is needed.
2400
One teaspoon of salt contains ... milligrams of sodium
animal, plants
Overall, minerals from ... products are better absorbed than those from ... because binders such as fiber are not present to hinder absorption. Also, the mineral content of plants greatly depends on mineral concentrations of the soil in which they are grown.
50-70
Overall, water comprises ...% of the human body
Saliva Mucus Spinal fluid Respiratory tract Urine Skin Eyes
Provide two examples of water's role as a lubricant.
trace minerals, iron, whole grains
Refined grains lose majority of vitamin E, B vitamins and ... Enrichment adds ... (but not selenium, zinc, copper); minerals preserved in ....
iron, calcium
Several beneficial vitamin-mineral interactions occur during nutrient absorption and metabolism. When consumed in conjunction with vitamin C, absorption of certain forms of ...—such as that in plant products—improves. The active form of the vitamin D hormone improves ... absorption.
Avoid taking individual mineral supplements; Compete for absorption
Should people take individual mineral supplements? Why or why not?
Low blood potassium: hypokalemia
Symptoms: loss of appetite, muscle cramps, confusion, constipation Can result from chronic deficient intake Most commonly seen with high losses from: chronic diarrhea or vomiting; side effect of medications such as laxative or diuretics
mineral toxicity
Taking minerals in supplement form poses the biggest threat for ..., whereas food sources are unlikely culprits. Mineral supplements exceeding current standards for mineral needs—especially those that supply more than 100% of the Daily Values on supplement labels—should be taken only under a primary care provider's supervision.
pituitary gland, high
The ..., located in the brain, senses the concentration of solutes in the blood. When blood concentration of solutes is ..., the pituitary gland releases ADH. The kidneys respond to ADH by reducing urine production and output. ADH also causes blood vessel constriction, which acts to raise blood pressure.
Age, gender, genetic, nutritional, diet, prescription drugs
The bioavailability of minerals depends on many factors, including many nonmineral components of foods. ..., ..., ... variables, ... status, and ... will affect mineral absorption and bioavailability. Numerous ... also adversely affect mineral absorption.
antidiuretic hormone (ADH), angiotensin, aldosterone
The blood pressure and the concentration of solutes in the blood are closely monitored by receptors in the kidneys, blood vessels, and brain. Once the body registers a shortage of available water, it increases fluid conservation. Hormones that participate in this process are ..., ..., and ....
osmosis, isotonic
The term ... is used to describe the passage of water through a membrane from an area of lower electrolyte concentration to an area of higher electrolyte concentration. Where ions move, water follows passively. Under normal conditions, the concentration of electrolytes on either side of the cell membrane is controlled in such a way that the intracellular fluid and extracellular fluid are ....
pepperoni pizza, ham steak, soup
Three high dietary sources of sodium?
Trace mineral
Vital to health, required in the diet in amounts <100 mg per day
Major mineral
Vital to health, required in the diet in amounts >100 mg per day
non-heme iron, calcium
Vitamin C enhances ...absorption Active vitamin D improves ... absorption
calcium, magnesium, sodium
Water can be classified as either hard or soft. Hard water contains relatively high levels of the minerals ... and .... In North America, 89% of homes have hard water. Naturally occurring soft water, which can be high in ..., is found in the Pacific North and Northwest, New England, South Atlantic-Gulf, and Hawaii.
electrolytes
Water flows toward greater concentration of ...
intracellular fluid
Water found inside the cell membrane is part of the ....
ideal transport vehicle for nutrients and wastes, medium for many chemical reactions of human metabolism
Water is often called the "universal solvent" because so many different solutes can be dissolved in it. This property of water makes it (1) an .... and (2) a ....
respiration, perspiration, excretion
We must replenish water regularly because the body does not store it per se. Fluids must be consumed daily to replenish what is lost through ... (lungs), ... (skin), and ... (urine and feces).
Heme iron Iron provided from animal tissues in the form of hemoglobin and myoglobin Approximately 40% of the iron in meat, fish, and poultry is heme iron Readily absorbed Nonheme iron Iron provided from plant sources, supplements, and animal tissues other than the forms of hemoglobin and myoglobin Less efficiently absorbed; absorption dependent on body needs Vitamin C and MFP protein
What are heme and nonheme iron? What can you do to enhance your absorption of nonheme iron?
Most fluoride comes from oral hygiene products and the water supply Food sources: marine fish, clams, lobster, crab, shrimp, tea, seaweed
What are our primary sources of fluoride?
delayed wound healing, impaired immunity, reduced sense of taste and smell In children and adolescents: growth, sexual development and learning ability hampered
What are the consequences of zinc deficiency?
An enlargement of the thyroid gland as it attempts to take up more iodide from bloodstream
What are the effects of iodide deficiency? What is a goiter?
* Nerve and heart function Aids in muscle relaxation after contraction * Mostly found in bones Provides rigidity Required for synthesis of vitamin D in liver Promotes resistance to tooth decay * Assists in the operation of enzymes
What are the key functions of magnesium other than bone health?
Cellular replication and growth Primary component of ATP Primary negatively charged ion in ICF
What are the key functions of phosphorus beyond bone health?
plant products, whole grains, beans, nuts, seeds
What are the primary food sources of magnesium?
Milk, cheese, meat, bread (20-30% of dietary phosphorus comes from food additives in baked goods, cheeses, processed meat and soft drinks)
What are the primary food sources of phosphorus?
Exceeding UL can result in mineralization of soft tissues High phosphorus and low calcium can lead to a chronic imbalance, contributing to bone loss
What are the risks of excess intake of phosphorus?
Deficiency is NOT common Selenium content of foods dependent on soil content May impair thyroid function
What are the signs of a selenium deficiency?
Osteopenia A bone disease defined by low mineral density Osteoporosis Porous trabecular & cortical bone characterized by rapid bone demineralization with aging. The body taps into bone when blood calcium is low Dowagers hump (kyphosis) Fractures
What are the two types of osteoporosis and how do they differ?
kidney diseases, hormonal abnormalities or medications Calcium absorption can be reduced by the presence of oxalates, tannins, and phytic acid, which bind to calcium
What factors reduce calcium absorption?
Animal sources: Fish, meat, shellfish, eggs Plant sources: brazil nuts, grains and seeds grown in selenium-rich soil
What food groups are the best sources of selenium?
Most accurate test for assessing bone density is dual energy X-ray absorptiometry (DEXA) -Measures the ability of the bone to block the path of a very low dose of radiation -T-score generated compares the observed bone density to that of a person at peak bone mass
What is the most accurate test for bone density and how is it done?
Most important factor influencing iron absorption is need When iron stores are inadequate or needs are high transferrin more readily binds iron If iron stores are adequate and the iron-binding protein in the blood is fully saturated, absorption from intestinal cells is minimal
What is the most important factor affecting absorption?
Supports thyroid hormone synthesis
What is the role of iodide in thyroid metabolism?
Potentially fatal condition that occurs with a high intake of water, which results in severe dilution of the blood and other fluid compartments
What is water intoxication?
Helps maintain cell membrane integrity Component of essential enzyme for activation of thyroid hormone
What other functions does selenium play in the body?
99% of calcium in the body is used for bone
What percent of calcium in the body is found in bone and teeth?
Trabecular bone (The less dense, more open structure bone found in the inner layer of bones)
What type of bone is most affected by osteoporosis?
metabolic water
When carbohydrates, lipids, and proteins are metabolized as sources of energy, water is one of the by-products. In fact, this ...(1 cup or more per day) contributes to the maintenance of fluid balance in the body.
Can occur in individuals who underconsume calcium and overconsume soft drinks
When is magnesium toxicity most likely to occur?
heart, slowed
When the kidneys function poorly, potassium builds in the blood, inhibiting ... function and leading to a ... heartbeat. If left untreated, the heart eventually stops beating, resulting in a cardiac arrest and death.
kidneys
Which organ regulates the amount of sodium in your blood?
May be seen in chronic disease (kidney ds.)
Who is at greatest risk of developing a magnesium deficiency?
Water transports nutrients and wastes - Majority of nutrients are water soluble Metabolism generates wastes which dissolve in water and are excreted as part of urine Water is a medium for chemical reactions
Why is it significant that water is the "universal solvent"?
zinc, iron
With calcium supplements, interactions with other minerals are a concern. There is evidence that calcium supplements may decrease ..., ..., and other mineral absorption. An effect of calcium supplementation on iron absorption is possible; however, this appears to be small over the long term.
Osmosis
... - movement of water across the cell membrane from an area of low [solute] to an area of high [solute]
Fluoride
... is added to many municipal water supplies to prevent dental caries
blood pressure increases along with sodium intake
Define sodium sensitivity.
Takes much more energy to heat water than air- Because majority of body is water, much energy is needed to change body temperature Evaporation of perspiration from the skin releases heat
Describe how water regulates body temperature.
600
Each quart (approximately 1 liter or 2 pounds) of perspiration that evaporates represents approximately ... kilocalories of energy lost from the skin and surrounding tissues.
functions of sodium
Electrolyte - attracts water Concentration of Intracellular and Extracellular fluids controlled by concentration of electrolytes Fluid balance Kidneys important filter Major part of fluid & electrolyte balance intake increases blood pressure -Hypertension -Prehypertension
Mineral
Element used in the body to promote chemical reactions and to form body structures
cell metabolism
Calcium Phosphorus Magnesium Zinc Chromium Iodide Water
acidic, small intestine
Calcium requires an ... environment in the gastrointestinal tract to be absorbed efficiently. Absorption occurs primarily in the upper part of the ..... This area tends to remain somewhat acidic because it receives the acidic stomach contents.
abnormal cognitive development
Children with chronic anemia have ...
extracellular
Chloride (Cl−) is a negative ion found primarily in the ... fluid.
Most dietary intake is from salt added to foods
Chloride in diet?
fiber, iron, zinc
Components of ..., such as phytic acid (phytate) and oxalic acid (oxalate), can limit absorption of some minerals by binding to them. High-fiber diets—particularly those in excess of current recommendations of 25 (adult women) to 38 grams (adult men) of fiber per day—can decrease the absorption of ..., ..., and possibly other minerals.
2400, 2300 - 4700
For sodium: DV: .. milligrams Average intake: ...mg 10-15% of adults are sodium sensitive (blood pressure increases along with sodium intake)
extracellular, intracellular
Four electrolytes predominate: sodium (Na+) and chloride (Cl−) are primarily found in the .... fluid, and potassium (K+) and phosphate (PO4−) are the principal electrolytes in the ... fluid.
Just iodized salt
Is salt always a good source of iodide?
oxalates, phytic, Oxalates,
Keep in mind, however, that many factors can influence the bioavailability of calcium. Calcium absorption can be reduced by the presence of ..., tannins, and ... acid. These compounds chelate (chemically bind) calcium in the digestive tract. ... are found in sweet potatoes, collard greens, spinach, and rhubarb. It is estimated that a person would have to consume over eight servings (8 cups) of spinach to absorb the same amount of calcium present in one serving (1 cup) of milk! Oxalates bind only the calcium in the food they are in; oxalate-containing foods do not affect the calcium availability from other foods.
White bread Hot dogs and lunchmeats Cheese Soups Tomato sauces
List three food sources of sodium in your diet.
High protein diets, rich in animal sources, are high in zinc oysters, beef, cheese
List three good sources of zinc.
Unprocessed foods are rich sources: - fruits, vegetables, milk, whole grains, dried beans, and meats (The more processed your food, the higher it is in sodium and the lower it is in potassium)
List three specific changes you could make to your diet to increase your potassium intake.
pale skin, fatigue upon exertion, poor temperature regulation, loss of appetite, apathy Iron-deficiency anemia is severe iron deficiency, characterized by decreased oxygen carrying capacity
List three symptoms of iron deficiency. How do these symptoms relate to the roles of iron in the body?
Negative ion found primarily in Extracelllar fluid Fluid balance component of hydrochloric acid in stomach
List two functions of chloride in the body.
Water balance -Intracellular fluid contains 95% of the potassium in the body -Positiely charged ion inside cell Nerve impulse transmission -heartbeat
List two functions of potassium in the body.
The thirst mechanism can lag behind actual water loss during prolonged exercise and illness; decreases with age
List two situations in which thirst is not a reliable indicator of fluid needs.
hypokalemia, decreasing
Low blood potassium, also known as ..., is a life-threatening problem. Symptoms often include a loss of appetite, muscle cramps, confusion, and constipation. Eventually, the heart beats irregularly, ... its capacity to pump blood.
