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Unit 6 Bone, Blood, and Immunity Health Bone Health Bones Bones are living _____________ that contain Bone tissue _______________ ______________ _________________ tissue Blood vessels supply ___________________ to bone to support its activities Bone provides strength and flexibility Contains about ____% minerals, providing the hardness of bone Contains ____% organic structures for strength, durability, and flexibility __________________: fibrous protein in bone tissue ________________________: mineral crystals around collagen designed to bear weight Bone Health Two types of bone tissue: ________________ bone (____________________ bone) Very _________ tissue Outer surface of bone 80% of the skeleton. ____________________ bone (_________________ bone) “___________________” on the inside of bones Supports cortical bone 20% of the skeleton. Faster turnover rate (sensitive to hormonal changes and nutritional deficiencies) Bones develop through three processes: Bone _______________ - increase in bone size Completed by age 14 in girls and age 17 in boys Bone _______________ - shaping of bone Completed by early adulthood Exercise and overweight increase bone thickness Bone ______________________ - recycling of bone tissue Bone remodeling involves: ______________________ – surface of bones is broken down by ______________________, cells that erode the surface of bones Formation of new bone matrix by ____________________, cells that produce the collagencontaining component of bone that is then mineralized Bone density (compactness of bones) Peak bone density is reached before the age of _____ when bones are ___________ Remodeling maintains bone density during early adulthood Density begins to __________________ after age 40 because __________________ exceeds new bone formation Factors associated with a lower peak bone density: Late pubertal age in boys Late onset of menstruation in girls Inadequate calcium intake Low body weight Physical inactivity during the pubertal years What are the methods of measuring bone density? Dual energy X-ray absorptiometry (_______) Measures bone density with very low level X-ray energy Scans the full body, or hips and spine Is a non-invasive procedure Results are compared with average peak bone density of 30-year old healthy adult ____-score is used to assess a person’s risk for fracture and diagnose osteoporosis Recommended for postmenopausal women Quantitative ______________________ technique Uses sound waves to measure density in the heel, shin and kneecap _____________________ dual energy x-ray absorptiometry Similar to DXA but only measures wrist, heel or finger Nutrients Involved in Bone Health Calcium is the most recognized nutrient associated with bone health Also essential for bone health: Calcium (____) Calcium is the most ________________ major mineral in the body Calcium absorption Is enhanced in an _____________ environment Requires 1,25-dihydroxyvitamin D Functions of calcium Provides ________________ for bones and teeth Assists with acid−base ___________________ Transmission of nerve impulses Assists in ________________ contraction Maintains healthy blood pressure Initiates blood clotting Regulates hormones and enzymes Recommended dietary intake Adequate Intake (AI) vary with age and gender from 1,000 mg to 1,300 mg per day Upper Limit (UL): 2,500 mg ________________________ – the body’s ability to absorb and utilize calcium depends on The individual’s age and need for calcium The amount of dietary calcium and vitamin D Binding factors (phytates, oxalates) in foods Excellent sources include milk products skim milk, low-fat cheese, nonfat yogurt Other good sources include __________________ foods (cottage cheese, orange juice) Green leafy vegetables (kale, collard greens, broccoli, and cabbage are low in oxalates) Fish with edible bones (sardines, salmon) What if you consume too much calcium? Excess dietary calcium is __________________________ in feces Mineral imbalances from supplements ____________________________ (high blood calcium) can be caused by cancer or PTH overproduction Symptoms: fatigue, appetite loss, constipation, mental confusion, calcium deposits in soft tissues What if you don’t consume enough calcium? _____________________ from long-term calcium deficiency ______________________ (low blood calcium) can be caused by kidney disease, vitamin D deficiency, or low PTH production Symptoms: muscle spasms and convulsions Osteoporosis is a disease characterized by low bone mass deterioration of bone tissue fragile bones leading to bone-fracture risk bone compaction: decreased height shortening and hunching of the spine: kyphosis (dowager's hump) Factors influencing the risk of osteoporosis include: ____________ Bone mass decreases with age Age-related hormonal changes influence bone density Decreased vitamin D metabolism with age Factors influencing the risk of osteoporosis include: _______________ 80% of Americans with osteoporosis are women Women have lower bone density than men Low estrogen production increases bone loss: post-menopausal women and adolescent girls engaged in extreme dieting At risk: Caucasian women of low body weight with first-degree relative (mother or sister) with osteoporosis ______________ and poor __________________ increase osteoporosis risk Cigarette smoking effects hormones that influence bone formation and resorption Alcoholism is associated with fractures Caffeine may increase urinary calcium loss Dietary protein and calcium interaction Low calcium and vitamin D intakes result in low bone density _________________________________ Regular exercise stresses bone tissues, stimulates increases in bone density Weight-bearing activities (walking, jogging) are especially helpful in increasing bone mass Improved muscle strength and physical stability reduces the risk of falling and bone fractures Nutrition and Osteoporosis Fruit and vegetable consumption associated with improved bone health good sources of vitamins C and K, and magnesium Protein: effect on bone health is controversial high intake may increase calcium loss low-protein intake also associated with bone risks Calcium & vitamin D are important throughout the life span Sodium: high intakes appear to have a negative impact, but studies are inconclusive Osteoporosis There is ______________________ for osteoporosis. The progression of osteoporosis may be _____________________ by Adequate calcium and vitamin D intake Regular (weight-bearing) exercise Resistance training Anti-resorptive medications (may have side affects) Vitamin D _____________-soluble vitamin Excess is stored in liver and adipose tissue Can be synthesized by the body by exposure to ______ light from the sun Considered a _________________: synthesized in one location and regulates activities in other parts of the body Functions of vitamin D Regulates blood calcium levels (regulates calcium and phosphorus absorption from the small intestine) Stimulates ______________________ when calcium is needed elsewhere in the body Required for bone _________________________ Recommended intake AI: assume sun exposure is inadequate Inadequate sun in the winter (latitude of more than 40°N or more than 40°S) Darker skin (more melanin pigment) reduces the penetration of sunlight People >65 years: decreased capacity to synthesize vitamin D from the sun Obesity: lower circulating vitamin D levels RDA: 600 IU for men/women ages 19 to 70; 800 IU for adults over age 70 UL: 4,000 IU for everyone over 9 years of age Controversy: recent evidence suggests that the current RDA is not sufficient to maintain optimal bone health and reduce the risks for diseases such as cancer Sources of vitamin D Ergocalciferol (D2)—plants, supplements Cholecalciferol (D3)—animal foods, sun Most foods naturally contain little vitamin D Mostly obtained from fortified foods (e.g., milk) High amounts: cod liver oil, fatty fish (salmon, mackerel, and sardines) Vegetarians not consuming milk products receive vitamin D from the sun, fortified soy or cereal products, or supplements What if you consume too much vit D? Can occur from vitamin supplements Results in ___________________ (high blood calcium) What if you don’t consume enough vit D? Can occur with diseases that reduce intestinal absorption of fat __________________ – occurs in children __________________ – occurs in adults Medications alter vitamin D metabolism and activity: glucocorticoids, phenobarbital Vitamin K Fat-soluble vitamin stored in the liver ________________ – plant form of vitamin K ___________________ – form of vitamin K produced by bacteria in the large intestine Functions of vitamin K Blood ________________________ ______________ metabolism "Gla" protein production Osteocalcin: secreted by osteoblasts (bone remodeling) Matrix Gla protein: in protein matrix of bone, cartilage, blood vessel walls, soft tissues Recommended intake There is ___ RDA for vitamin K AI values are 120 mg/day for men and 90 mg/day for women Sources of vitamin K Synthesized by bacteria in the large intestine Green leafy vegetables, vegetable oils What if you consume too much vit K? No known side effects from large quantities What if you don’t consume enough vit K? _______________ blood clotting, excessive bleeding Fat malabsorption (celiac disease, Crohn's disease, and cystic fibrosis) Long-term use of _________________ can lead to deficiency Injection of vitamin K at birth for newborns Phosphorus (___) Phosphorus (as phosphate) is the major intracellular negatively charged ___________________ An essential component of all cells, found in both plants and animals Functions of phosphorus Critical to mineral composition of __________________ Required for proper fluid balance Component of ATP, DNA, membranes Recommended intake RDA for phosphorus is 700 mg/day Sources of phosphorus High in ________________-containing foods such as milk, meats, eggs In processed foods as a food additive: smoothness, binding, and moisture retention In soft drinks as phosphoric acid (milk-displacement effect) What if you consume too much phosphorus? Excessive vitamin D supplements or phosphorus-containing antacids can cause high phosphorus levels, muscle spasms, and convulsions What if you don’t consume enough phosphorus? Deficiencies are rare in healthy adults Can occur in alcohol abuse, premature infants, and elderly people with poor diets Magnesium (_____) About ____________% of the body’s magnesium is found in the bones Functions of magnesium A mineral found in bone structure Cofactor for over _______ enzyme systems Required for ATP, DNA, and proteins Supports vitamin D metabolism, muscle contraction, and blood clotting Required for ________ activation Recommended intake RDA varies based on age and gender UL (pharmacological): 350 mg/day Sources of magnesium Green leafy vegetables, whole grains, seeds, nuts, seafood, beans, some dairy products Dietary protein enhances absorption and retention What if you consume too much magnesium? Excess supplements cause diarrhea, nausea, cramps, dehydration, acid–base imbalances ________________ occurs in individuals with impaired kidney function (antacid) What if you don’t consume enough magnesium? __________________: results in hypocalcemia; associated with osteoporosis, heart disease, high blood pressure, type 2 diabetes Fluoride (___) Fluoride is a ____________ mineral. About 99% of the body’s fluoride is stored in teeth and bones Functions of fluoride Development and ____________________ of teeth and bones Combines with calcium and phosphorus to protect teeth from bacteria Recommended intake AI varies by gender and increases with age, ranging from 1-4 mg/day Sources of fluoride Fluoridated _______________________ Fluoridated ____________ What if you consume too much fluoride? __________________ (excess fluoride) creates porous tooth enamel; teeth become stained and pitted What if you don’t consume enough fluoride? Dental caries (cavities) Blood Health Blood Blood is the only ________________ tissue in the body Functions ________________ of oxygen and nutrients to cells Removal of ______________ products from tissues due to metabolic reactions Components of blood __________________—red blood cells transport oxygen through the body __________________—white blood cells are key to our immune system __________________—cell fragments assist in blood clotting __________________—fluid portion of the blood maintains adequate blood volume Nutrients Involved in Blood Health and Immunity Iron (____) Iron is a _______________ mineral Functions of iron Component of oxygen-carrying ________________ and ___________________ (muscle) Component of _________________, electron carriers within the metabolic pathways for energy production from carbohydrates, fats, and protein Maintaining Iron Homeostasis Regulation of iron digestion, absorption, transport, storage, and excretion Factors that alter iron digestion and absorption Individual's iron status Level of dietary iron consumption Type of iron in foods Amount of stomach acid for digestion Dietary factors enhance or inhibit absorption Two types of iron in foods ___________ iron—found only in animal-based foods and more absorbable _______________ iron—not as easily absorbed Factors that promote iron absorption ____________ factor Stomach _____________ Vitamin C Factors that impair iron absorption Phytate (legumes, rice, and whole grains) Polyphenols (oregano, red wine, tea, coffee) Vegetable proteins Bioavailability of iron from vegan diet is approx. 1-10%, vs. typical Western diet's absorption of 14−18% Iron transport __________________: iron-transport protein in blood Receptors on cells transport iron into cells Iron storage ______________ and hemosiderin help meet iron needs Liver, bone marrow, and spleen Regulation of total-body iron: Iron ____________________ Iron losses Storage and recycling of iron Recommended intake RDA varies based on age and gender __ mg/day for adult men ____ mg/day for pregnant women Sources of iron Meat, poultry, fish, clams, oysters, enriched or fortified cereals and breads Supplements What if you consume too much iron? Accidental iron overdose is the most common cause of poisoning deaths in children _________________________: Overabsorb iron→Deposition in tissues Consequences of toxicity Stomach irritation Increased formation of free radicals ________________ due to respiratory collapse (shock) Treatment: reduce dietary iron, avoid high vitamin C intake, blood removal What if you don’t consume enough iron? Most common nutrient _______________ in the world High risk: infants, young children, adolescent girls, premenopausal and pregnant women Poor dietary intakes Iron losses in blood and sweat Diets high in fiber or phytates that bind iron Low stomach acid Poor iron absorption (poor gut health or dietary supplements with high mineral levels, e.g., calcium) Stages of Iron Deficiency 1. ________________ is caused by a decrease in iron stores 2. Iron-deficiency __________________ occurs with decreased iron transport 3. Iron-deficiency ____________ results in reduced normal, healthy red blood cell production, decreased size, inadequate hemoglobin Zinc (____) Zinc is a _______________ mineral. Functions of zinc Component of enzymes (______________ synthesis) Maintain _______________ integrity and shape of proteins Assist in regulating gene ___________________ Recommended intake RDA is 8 mg/day for women, 11 mg/day for men Absorption increases with need: growth, sexual development, pregnancy Dietary factors inhibit zinc absorption _______________ non-heme iron intake _______________ and fiber (whole grains, beans) Dietary factor enhances zinc absorption Animal-based ________________ Sources of zinc Red meats, some seafood, whole grains, enriched grains and cereals What if you consume too much zinc? Toxicity can occur from supplements Symptoms: intestinal pain, cramps, nausea, vomiting Depressed ________________ function ________________ high-density lipoprotein concentrations Interference with copper and iron absorption What if you don’t consume enough zinc? Deficiencies are uncommon in the United States Symptoms: growth retardation, diarrhea, delayed sexual maturation, hair loss, impaired appetite, infections Lack of good assessment parameters for zinc Copper (____) Copper is a ___________ mineral Functions of copper Required for __________ transport __________________ in energy metabolism and for connective tissue production Part of _______________________ antioxidant enzyme system Regulates ________________________ (serotonin) Factors that promote copper absorption More copper is absorbed with low-copper diet Factors that impair copper absorption High _________ intakes High _________ intakes Recommended intake RDA for adults is 900 µg/day Sources of copper Organ meats, seafood, nuts, seeds, whole grain foods What if you consume too much copper? Toxicity is not well studied in humans Symptoms: abdominal pain, nausea, diarrhea, vomiting, liver damage (Wilson disease) What if you don’t consume enough copper? Copper deficiency is __________ Symptoms: anemia, reduced white blood cells, osteoporosis (children—bone demineralization) Vitamin K Vitamin K is a fat-soluble vitamin important for both bone and blood health Function of vitamin K Coenzyme assists in synthesizing blood _______________ proteins: prothrombin and procoagulants, factors VII, IX, and X Factors that promote vitamin K absorption Gastrointestinal _____________ produce vitamin K Dietary need depends on _____________ health Factors that impair vitamin K absorption Impaired dietary _________ absorption Recommended intake AI for adults is 90-120 µg/day No established UL at this time Sources of vitamin K Green leafy vegetables, such as collard greens, kale, spinach, cabbage Soybean and canola oils What if you consume too much vitamin K? No known side effects What if you don’t consume enough vitamin K? Deficiency is rare Blood fails to ___________, bleeding, _______________________ Fat ______________________ Newborns lack intestinal bacteria to produce vitamin K (injection at birth) Folate Folate is a _____________-soluble vitamin Functions of folate __________ synthesis, amino acid metabolism Cellular _________________ and ________________ Functions with B12 and B6 metabolism Factors that alter folate digestion, absorption, and balance Bioavailability depends on its source: better from supplements than from food Alterations in folate status mimic those of iron Four states of folate deficiency: 1) Negative folate balance (stage I) 2) Folate depletion (stage II) 3) Folate deficiency erythropoiesis (stage III) 4) Folate deficiency anemia (stage IV) Recommended intake RDA for adults is 400 µg/day, 600 µg/day during pregnancy Sources of folate Fortification to minimize birth defects: enriched breads, flours, pasta, grain products Liver, spinach, lentils, oatmeal, asparagus Heat-sensitive, can be leached out in cooking liquid What if you consume too much folate? Toxicity can result from supplements Toxicity can ___________ vitamin B12 deficiency Symptoms: intestinal pain, nausea, vomiting What if you don’t consume enough folate? _______________ anemia Elevated ___________________ ______________ tube defect Folate's role in neural tube defects (NTDs) Need for folate increases during _________________ NTDs = most common malformations of the CNS during embryonic and fetal development Most common NTD is _______________________ Biggest challenge: NTDs occur early in pregnancy, sometimes before the pregnancy is known Why? Hence, adequate folate intake is important for sexually active women of childbearing age Folate's role in macrocytic anemia _______________ anemias = larger than normal red blood cells that inhibit adequate oxygen transport Symptoms include fatigue, irritability, difficulty concentrating, headaches, shortness of breath, reduced capacity for work Similar symptoms can result from vitamin B12 deficiency, so it's important to distinguish the cause Vitamin B12 Vitamin B12 is a _____________ soluble vitamin Functions of vitamin B12 _______________ for DNA synthesis Maintains _______________ sheath of nerve fibers _________________ of amino acid homocysteine Factors that alter vitamin B12 digestion, absorption, and balance Requires acidic environment (stomach) and protein _____________________ for absorption Stored in the liver Four levels of vitamin B12 deficiency Recommended intake RDA for adults is 2.4 µg/day Sources of vitamin B12 Found primarily in dairy products, eggs, meats, poultry, fish, and shellfish (animal sources) Vegan diet may obtain vitamin B12 from fortified foods, supplements, or injections What if you consume too much vitamin B12? No known adverse effects What if you don’t consume enough vitamin B12? Deficiency is rare, but associated with dietary insufficiency or reduced absorption Gastrointestinal and neurologic effects Pernicious anemia (lack intrinsic factor) _____________ anemia Vitamin B12 role in _____________________ anemia Special form of anemia occurring after the ___________ of specific cells of the stomach Primary cause of vitamin B12 deficiency is the ____________ of intrinsic factor Also occurs in people who consume very little vitamin B12 in their diet Symptoms are pale skin, reduced energy, fatigue, neurological symptoms Vascular Disease Folate and vitamin B12 are required for the breakdown of the amino acid _________________ Low folate and vitamin B12 intake may increase the level of homocysteine High homocysteine levels are associated with greater ________________ and _____________________ disease risk Immune System What Is the Immune System? A healthy immune system ... Protects the body from _____________ diseases Helps _____________ wounds Guards against the development of _________________ How Does It Function? _____________________ immune function Body's primary defense against microbes, airborne particles, venom, ingested toxins Also called ________________ immunity Intact skin and healthy mucous membranes Stomach acid destroys food-borne bacteria Inflammatory response causes discomfort, loss of appetite, fatigue, and fever A _____________________ is a type of nonspecific immune cell. The one shown here is about to engulf an invading microbe. _____________________ immune function Directed against recognized ___________________ Induces antibodies to destroy invader ___________________ cells remain in circulation Two main types of cells: _____ cells and _____ cells Acquiring specific immunity Have disease or vaccinations (________________________) ________________ antibodies ____________________ injection (snakebite) Malfunction can cause chronic inflammation and infection ________________ reactions ________________ response Common in malnourished _____________________ How does nutrition affect the immune system? A nourishing diet provides all the nutrients the immune system needs Single-nutrient subclinical deficiencies can cause subtle abnormalities in immunity Protein/energy malnutrition and severe deficiencies of several micronutrients result in functional immunodeficiency Protein/energy malnutrition impairs immune function Malnutrition increases the risk for ________________ Infection depresses _________________ and often causes vomiting and diarrhea Decreased appetite, vomiting, and diarrhea cause malnutrition, which increases vulnerability to infection Decreased __________________________ is a sensitive indicator of reduced nutritional status Overnutrition/Obesity increases incidence and severity of infections Increases __________________ of infections ________________ wound healing Poor _____________________ response to vaccination Inflammatory state may increase asthma, hypertension, cardiovascular disease, and type 2 diabetes among obese individuals Essential fatty acids make signaling molecules for the immune system Essential fatty acids are precursors for signaling molecules ___________________________ Omega-6 fatty acids promote inflammatory response to help contain infection Omega-3 fatty acids diminish inflammation in blood vessels (prevent heart disease) Certain vitamins and minerals are critical to a strong immune response Vitamin ___ maintains mucosal surface Vitamins ___ and ____ protect cell membrane from reactive _____________ species Zinc assists immune cell gene ________________ and enzyme activation (B and T cell proliferation) ___________: growth factor for immune cells ___________ deficiency impairs immune function _________________: Coenzyme for glutathione peroxidase Promotes B and T cell proliferation Antibody production Excessive amounts can impair immunity