Sources of Nutrition (Nutrition Ch 1) Flashcards
Carbohydrates
- organic compounds composed of carbon, hydrogen, and oxygen (CHO)
- main function: provide energy for the body
- ave. min. amount to fuel the brain = 130 g/day
- median intake for men = 200-330 g/day
- median intake for women = 180-230 g/day
- acceptable macronutrient distribution range for carbs is 45-65% of calories
- provide energy for cellular work and help regulate protein and fat metabolism
- essential for normal cardiac and CNS functioning
- provide 4 cal/g of energy
3 types of carbohydrates
- classified according to # of saccharide units making up their structure
1) monosaccharides: simple carbs (glucose, fructose)
2) disaccharides: simple carbs (sucrose, lactose)
3) polysaccharides: complex carbs (starch, fiber, glycogen)
Complex carbohydrates
-as they are ingested and broken down, they are easily absorbed in the intestine and bloodstream where they are stored in the liver and muscles for energy needs.
Glycogen
- the stored carbohydrate energy source found in the liver and muscles.
- vital source of backup energy
Fiber
- categorized as carbohydrate, but does not yield energy for the body
- it is the substance in plant foods that is indigestible (pectin, gum, cellulose, and mucilage)
- important for proper bowel elimination–adds bulk to feces and stimulates peristalsis to ease elimination
Monosaccharides
- glucose (corn syrup)
- fructose (fruits)
- galactose (milk sugar broken down)
*basic energy for cells
Disaccharides
- sucrose (table sugar, molasses)
- lactose (milk sugar)
- maltose (sweeteners)
*energy, aids calcium and phosphorus absorption (lactose)
Polysaccharides
- starches (grains, legumes, root vegetables)
- fiber (indigestible plant parts)
*energy storage (starches), digestive aid (fiber)
Proteins
- provided by plant and animal sources
- formed by linking amino acids in various combinations for specific use by the body
- many metabolic functions: tissue-building and maintenance, balance of nitrogen and water, backup energy, support of metabolic processes [nitrogen balance, transportation of nutrients, other vital substances], support of immune system
- provide 4 cal/g of energy
3 types of proteins
1) complete: generally obtained from animal sources, contain all 9 essential amino acids
2) incomplete: generally from plants (grains, nuts, legumes, vegetables, fruits), DO NOT contain all the essential amino acids
3) complementary: those food sources, when eaten together, provide all essential amino acids
3 main factors influence the body’s requirements for protein:
1) tissue growth needs
2) quality of the dietary protein
3) added needs due to illness
Recommended dietary requirement of protein for adults
-10% of intake, or 46 g/day for women and 56 g/day for men
Lipids (sources)
- dark meat
- poultry skin
- dairy foods
- added oils (margarine, butter, shortening, oils, lard)
Fat
- essential nutrient for the body
- serves as concentrated form of energy for body (2nd to carbs)
- supplies important tissue needs (hormone production, structural material for cell walls, protective padding for vital organs, insulation to maintain body temp, covering for nerve fibers, aids in absorption of fat-soluble vitamins)
- no more than 20-35% of total calories should come from fat (10% or less from saturated fat sources)
- *exception = children < 2 yrs, need higher amount of fat to develop brain tissue
- **provide 9 cal/g of energy
Categories of fat
1) triglycerides
2) phospholipids
3) sterols
4) saturated fats
5) unsaturated fats
6) polyunsaturated fats
7) essential fatty acids
Triglycerides
- primary form of fat in food
- combine with glycerol to supply energy to the body
- allow fat-soluble vitamin transport
- form adipose tissue that protects the body
Phospholipids
- derived from triglycerides
- important to cell membrane structure
Sterols (cholesterol)
- necessary for cell membrane stability and production of certain hormones and bile salts for digestion
- if consumed in excess, it can build up in tissues and cause congestion, increasing risk of CV disease
Saturated fats
-animal origin
Unsaturated fats
- usually from plant sources
- help reduce health risks (except coconut and palm oil)
Essential fatty acids
- made from broken down fats
- must be supplied by the diet
- omega-3 and omega-6
- used to support blood clotting, blood pressure, inflammatory responses, and many other metabolic processes
Lipid metabolism
- majority occurs after fat reaches small intestine, where the gallbladder secretes concentrated bile and acts as an emulsifier to break fat into smaller particles.
- at the same time, the pancreas secretes pancreatic lipase, which breaks down fat.
- small intestine secretes an enzyme for further breakdown
- muscles, liver, and adipose tissue cause the release of fatty acids
- liver produces lipoproteins to carry lipids
3 types of lipoproteins
1) very-low-density lipoproteins (VLDL): carry triglycerides to the tissues
2) low-density lipoproteins (LDL): carry cholesterol to the tissues
3) high-density lipoproteins (HDL): remove excess cholesterol from the tissues (“good” cholesterol)
Vitamins
- organic substances required for many enzymatic reactions
- main function: to be a catalyst for metabolic functions and chemical reactions
- 13 essential vitamins
- yield no usable energy for the body
2 classes of vitamins
1) water-soluble: vitamins C and B-complex
2) fat-soluble: vitamins A, D, E, and K
Vitamin C
ascorbic acid
- aids in tissue building and metabolic reactions (wound and fraction healing, collagen formation, adrenaline production, iron absorption, conversion of folic acid, cellular adhesion).
- found in citrus fruits (oranges, lemons), tomatoes, peppers, green leafy vegetables, and strawberries
- stress and illness increase need for vitamin C
- deficiency = scurvy (a hemorrhagic disease w/ diffuse tissue bleeding), decreased iron absorption, bleeding gums
Thiamin (B1)
- necessary for proper digestion, peristalsis, and providing energy to the smooth muscles, glands, the CNS, and blood vessels
- sources = meats, grains, legumes
- deficiency = beriberi, altered digestion, CNS and CV problems
Riboflavin (B2)
- required for growth and tissue healing
- sources = milk, meats, and green leafy vegetables
- deficiency = cheilosis (manifestations include scales and cracks on lips and mouth), smooth/swollen red tongue, and dermatitis particularly in skin folds
Niacin (B3)
- aids in metabolism of fats, glucose, and alcohol
- sources = beef liver, nuts, legumes, whole grain and enriched breads and cereals
- deficiency = pellagra (manifestations include sun-sensitive skin lesions, GI and CNS findings), dementia
Pantothenic acid (B5)
-involved in biological reactions (energy production, catabolism, and synthesis of fatty acids, phospholipids, cholesterol, steroid hormones, the neurotransmitter acetylcholine)
-sources = organ meats (liver, kidney), egg yolk, avocados, cashew nuts and peanuts, brown rice, soy, lentils, broccoli, and milk
-deficiency = anemia and CNS changes
(though unlikely due to the diverse availability in foods)
Pyridoxine (B6)
-needed for cellular function and synthesis of hemoglobin, neurotransmitters, and niacin
-sources = organ meats, grains
(high intake of supplements may cause sensory neuropathy)
-deficiency = anemia, CNS hyper-irritability, dermatitis
Biotin
- serves as a coenzyme used in fatty acid synthesis, amino acid metabolism, and formation of glucose
- sources = eggs, milk, dark green vegetables
- deficiency is rare, but results in neurological findings (depression, fatigue) and rashes on the skin
Folate
- folic acid = synthetic form
- required for hemoglobin and amino acid synthesis, cellular reproduction, and prevention of neural tube defects in utero
- sources = liver, green leafy vegetables, grains, legumes
- deficiency = megaoloblastic anemia, CNS disturbances, and fetal neural tube defects (spina bifida and anencephaly)
Cobalamin (B12)
- necessary for the production of RBCs
- sources = organ meats, shellfish, and fortified grains
- deficiency = pernicious anemia (seen mostly in strict vegetarians), GI findings, and poor muscle coordination
Fat-soluble vitamins
- have the possibility for toxicity because they can be stored in the body for long periods of time
- absorption is depended on the body’s ability to absorb dietary fat
Vitamin A
retinol, beta-carotene
- contributes to vision health, tissue strength and growth, and embryonic development
- some have teratogenic effects, care when administered to pregnant clients
- sources = fish liver oils, egg yolks, butter, cream, dark yellow/orange fruits and vegetables (carrots, yams, apricots, squash, cantaloupe)
- deficiency = vision changes, xerophthalmia (dryness and thickening of conjunctiva), and changes in epithelial cells (especially mouth and vaginal mucosa)
Vitamin D (calciferol)
-assists in utilization of calcium and phosphorus; aids in skin repair
-can be used preventively for immune function
-sunlight enables body to synthesize vitamin D
-sources = fortified milk, cod liver oil, eggs
-deficiency = bone demineralization
extreme deficiency = rickets
Vitamin E (tocopherol)
- antioxidant that helps to preserve muscles and RBCs, and maintains myelin sheath that insulates nerve cells
- sources = vegetable oils and certain nuts
- deficiency = hemolytic anemia and affects the nerve fibers that influence walking and vision
Vitamin K (menaquinone, phylloquinone)
- assists in blood clotting; aids in bone metabolism
- sources = green leafy vegetables (spinach, broccoli, cabbage), eggs, liver
- deficiency = increased bleeding times
- used as an antidote for excess anticoagulants (warfarin [Coumadin])
2 categories of minerals
1) MAJOR: occur in large amounts in the body
2) TRACE: (micronutrients) are required by the body in amounts of < 100 mg/day
7 MAJOR minerals
1) calcium
2) phosphorus
3) sodium
4) potassium
5) magnesium
6) chloride
7) sulfur
10 TRACE minerals
1) iron
2) iodine
3) zinc
4) copper
5) manganese
6) chromium
7) cobalt
8) selenium
9) molybdenum
10) fluoride
Electrolytes
-electrically charged minerals that cause physiological reactions that maintain homeostasis
Sodium
Na
- maintains fluid volume, allows muscle contractions, CV support
- major sources = table salt, added salts, processed foods, butter
- findings of deficiency = muscle cramping, cardiac changes
- findings of excess = fluid retention, hypertension, CVA
- nursing implications = monitor ECG, edema, and BP
Potassium
K
- maintains fluid volume inside/outside cells, muscle action, BP, CV support
- major sources = oranges, dried fruits, tomatoes, avocados, dried peas, meats, broccoli, bananas
- findings of deficiency = dysrhythmias, muscle cramps, confusion
- findings of excess = dysrhythmias (caused by supplements, potassium-sparing diuretics, ACE inhibitors, inadequate kidney function, diabetes)
- nursing implications = monitor ECG and muscle tone. PO tabs irritate the GI system–give w/ meals
Chloride
Cl
- bonds to other minerals (esp. Na) to facilitate cellular actions and reactions, fluid balance
- major sources = table salt
- findings of deficiency = rare
- findings of excess = in concert w/ Na, results in high BP
- nursing implications = monitor Na levels
Calcium
Ca
- bones/teeth, CV support, blood clotting, nerve transmission
- major sources = dairy, broccoli, kale, grains, egg yolks
- findings of deficiency = osteoporosis, tetany, Chvostek’s and Trousseau’s signs, ECG changes
- findings of excess = constipation, kidney stones
- nursing implications = monitor ECG and muscle tone. GIve PO tabs w/ vitamin D
Magnesium
Mg
- bone nourishment, catalyst for many enzyme reactions, nerve/muscle function, CV support
- major sources = green leafy vegetables, nuts, grains, meat, milk
- findings of deficiency = weakness, dysrhythmias, tetany, seizure, reduced blood clotting, eclampsia
- findings of excess = diarrhea, kidney stones, decreased muscle control, CV changes
- nursing implications = incompatible w/ some antibiotics. Give PO, 2 hr apart
Phosphorus
P
- energy transfer of RNA/DNA, acid-base balance, bone and teeth formation
- major sources = dairy, peas, soft drinks, meat, eggs, some grains
- findings of deficiency = Ca level changes, muscle weakness
- findings of excess = skeletal porosity, decreased Ca levels, must stay in balance w/ Ca
- nursing implications = evaluate use of antacids (note type) and use of alcohol
Sulfur
S
- component of vitamin structure, by-product of protein metabolism
- major sources = dried fruits (dates, raisins, apples), meats, red and white wines
- findings of deficiency = only seen in severe protein malnourishment, found in all protein-containing foods
- findings of excess = toxicity has a very low risk
- nursing implications = sulfur levels are not usually monitored
Iodine
- used for synthesis of thyroxine (thyroid hormone that helps regulate metabolism)
- taken up by thyroid–when lacking, thyroid gland enlarges, creating a goiter
- content in grown food sources depend on soil; seafood; U.S. table salt fortified w/ iodine
- RDA is 100-150 mcg for adults
Iron
- responsible for hemoglobin formation/function, cellular oxidation of glucose, antibody production, and collagen synthesis
- body “scavenges” unused iron from dying RBCs and stores for later use
- food sources = organ meats, egg yolks, whole grains, green leafy vegetables
- vitamin C increases absorption
- supplements may cause constipation, nausea, vomiting, diarrhea, and teeth discoloration (liquid form)
- take w/ food to avoid GI upset–nurses encourage fresh fruits, vegetables, and high-fiber diet
- IM injections are caustic to tissues—must be administered in Z-track method
- those w/ greatest need = newborns who are not breastfed and females during menstruating years
Fluoride
- forms bond w/ Ca and accumulates in calcified body tissue (bone and teeth)
- water w/ added fluoride protects against dental cavities
Water
- makes up largest portion of our total body weight and is crucial for all fluid and cellular functions
- to maintain a balance between I and O, intake should approximate output. Minimum daily total O in healthy adults = 1,500 mL. (thus min daily water needed is 1,500 mL)
- under normal conditions, recommended adult fluid intake is 3-4 L/day Men and 2-3 L/day Women. (half should be from water)
- additional hydration may be needed for athletes, persons w/ fever/illness (vomiting, diarrhea), and those in hot climate conditions
- young children & adults dehydrate more rapidly
- water leaves body by kidneys, skin, lungs, feces w/ greatest elimination through kidneys
- assessment for proper hydration = skin turgor, mental status, orthostatic BP, urine output and concentration, moistness of mucous membranes
- thirst = late sign of need for hydration
