Science of Nutrition Ch. 11

Osteoclasts

Bone-destroying cells 412

Hydroxyapatite

In bone, the calcium phosphate forms crystals of_______ 410

Vitamin D deficiency

Rickets in children (bending bones), osteomalacia in adults (soft bones), hypocalcemic tetany (Most common cause is renal fialure ) 424

Peak bone density

point at which bone is the strongest: has the highest mineral content. 411

Magnesium deficiency

rare, can occure as a result of: severe diarrhea, vomiting, heaving sweatins, alcoholism, medications 430

Calcium RDA

19-50 yrs old: 1000mg/day greater than 50 :1,200 mg/day 416

magnesium function

Bone mineralization, muscle contraction, nerve transmission, maintenance of teeth, immune integrity 429

Bone health

Calcium Vitamin D Vitamin K Phosphorous major mineral Magnisium major mineral Fluoride trace mineral Table 416

cholecalciferal

D3 423

Bone Health

Dual energy xray absdorptiometry 413

Magnesium

Helps build bones and teeth; helps build protein; helps muscles contract and relax; helps nerves communicate major mineral 429

Fluoride deficiency

Increased risk of dental decay 432

Magnesium RDA

Men: 400 mg/day 19-30 years old 420 mg/day 31 years and up Women: 310 mg/day 19- 30 years old 320 mg/day 31 years and up. 416

Calcium food sources

Milk and milk products, oysters, small fish (with bones), calcium-set tofu (bean curd), certain leafy greens, broccoli, legumes 417

Phosphorus food sources

Nuts Organ meats Whole grain breads and cereals Fish Pork, beef, chicken 428

Bone Health.- disorders affecting

Osteoporosis Is the Most Prevalent Disorder Affecting Bone Health.

Vitamin K food sources

Plants - dark green/green leafy veggies, cabbage, vegetable oils (soybean & canola)

Osteocalcin

This promotes ossification of bones Depends on Vit K to be there 426

Ergocalciferol

Vitamin D2 423

Fluoride

Which "mineral" helps strengthen teeth and prevent cavities trace mineral stored in teeth and bones 431

Hypocalcemia

abnormally low level of calcium in the blood 419

Phosphorus deficiency

weakness, loss of minerals from bones, calcium loss 428

Bone disorders

-Osteoporosis -arthritis -noninflammatory joint disease 433

Vitamin D function

-increased intestinal absorption of calcium and phosphate - bone mineralization -Stimulates macrophage stem cell conversion into osteoclasts 421

Vitamin D RDA

19-50yrs - 5mcg (200 international units) 51-70yrs - 10mcg (400 international units) 70yrs + - 15mcg (600 international units) 416

Fluoride RDA

4-8 1mg 9-13 2 mg 14-18 3 mg adult men 4mg / women 3mg 431

Bone composition

65% bone tissue assortment of minerals mostly calcium a;nd phosphorus 35% ;mixture of organic substances the provide strnetgth durzbility and flexibility Most important collegan 410

Phosphorus RDA

700 mg a day for adults 416

Parathyroid Hormone PTH

A hormone produced and secreted by the parathyroid glands that increases serum calcium levels. It targets the bones (stimulates osteoclasts), the kidneys (increases calcium reabsorption), and the small intestine (increases calcium absorption). 417

Fluorohydroxyapatite

A mineral compound in human teeth that contains fluoride, calcium, and phosphorous and is more resistant to destruction by acids and bacteria than hydroxyapatite. 431

Calcium

A mineral that is essential for bone growth, teeth development, blood coagulation, and many other functions 414

Matrix Gla protein

A vitamin K-dependent protein that is located in the protein matrix of bone and also found in cartilage, blood vessel walls, and other soft tissues. 426

Bone Health - maintain

A. Bone composition and structure provide strength and flexibility. 1. About 65% of bone tissue is made up of minerals. a. The most abundant minerals in bone are calcium and phosphorus. 2. About 35% of bone tissue is made up of organic substances. a. Collagen is a protein that forms strong fibers in bone and connective tissue. 3. There are two types of bone. a. Cortical bone is very dense and comprises 80% of our skeleton. b. Trabecular bone is porous bone tissue that makes up 20% of our skeleton. c. Trabecular bone has a higher rate of turnover and the loss of it is more easily detected. B. The constant activity of bone tissue promotes bone health. 1. Bone growth and modeling determine the size and shape of bones. a. Bone growth continues through childhood and adolescence. b. Modeling determines the shape of bones and continues to change with stress. 2. Bone remodeling maintains a balance between breakdown and repair. a. Bone density continues to develop into early adulthood. b. Bone mass is regularly recycled through remodeling. i. Resorption involves the action of osteoclasts eroding the bone surface. ii. Bone formation involves the action of osteoblasts laying down collagen.

Bone Health - How do we assess

A. Dual energy x-ray absorptiometry provides a measure of bone density. 1. A normal T-score is between +1 and -1. 2. Osteopenia or low bone density is indicated by a T-score of -1 to -2.5. 3. A T-score of less than -2.5 indicates osteoporosis. B. Other bone density measurement tools have been developed.

Bone Health - nutrients that maintain

Calcium Vitamin D is a fat-soluble vitamin and a hormone. Vitamin K, a fat-soluble vitamin, is a family of compounds known as quinones Phosphorus Magnesium is a major mineral. Fluoride is the ionic form of fluorine and a trace mineral.

Calcium

Calcium is the most abundant mineral in the body. 1. Calcium is absorbed via active transport and passive diffusion. a. Low to moderate calcium intake is reliant on vitamin D for active transport. b. At high calcium intakes, passive diffusion is a function of the calcium concentration gradient. 2. Calcium has many functions. a. Calcium provides structure to bones and teeth. b. Calcium assists with acid-base balance. i. Blood calcium levels must remain fairly constant. ii. Parathyroid hormone, calcitonin, and vitamin D maintain appropriate blood calcium levels. c. Calcium is critical for normal transmission of nerve impulses. d. Calcium assists in muscle contraction. i. Calcium tetany occurs when calcium is inadequate. ii. Calcium rigor is the result of high blood calcium levels. e. Calcium helps to maintain healthy blood pressure. f. Calcium initiates blood clotting. g. Calcium regulates various hormones and enzymes. 3. How much calcium should we consume? a. Calcium requirements vary with age and gender, and, for women, whether a woman is pregnant or breast-feeding. i. The AI for adults aged 19 to 50 is 1,000 mg and the UL is 2,500 for all ages. ii. The bioavailability of calcium depends on our age, need for calcium, how much is consumed at one time, and dietary factors. b. What are good food sources of calcium? i. Dairy products are the most common sources of calcium. ii. Green leafy vegetables are good sources of calcium. iii. Many packaged foods are fortified with calcium. iv. Those who consume little dietary calcium would benefit from supplementation. 4. What happens if we consume too much calcium? a. Consuming excess calcium can interfere with absorption of other minerals. b. Hypercalcemia, abnormally high blood calcium levels, is caused by alterations in the body's ability to regulate blood calcium and not by excessive consumption. 5. What happens if we don't consume enough calcium? a. There are no short-term symptoms associated with consuming too little calcium, as our bodies will remove calcium from bone if necessary. b. The long-term repercussion of low calcium intake is osteoporosis. c. Hypocalcemia is not caused by inadequate intake, but by certain diseases.

Fluoride is the ionic form of fluorine and a trace mineral.

Fluoride is the ionic form of fluorine and a trace mineral. 1. Functions of fluoride include development and maintenance of bones and teeth. 2. How much fluoride should we consume? a. Our need for fluoride is relatively small. b. What are good food sources of fluoride? i. The two primary sources of fluoride are fluoridated dental products and fluoridated water. 3. What happens if we consume too much fluoride? a. Consuming too much fluoride causes fluorosis of the teeth and skeleton. 4. What happens if we don't consume enough fluoride? a. The primary result of fluoride deficiency is dental caries.

Vitamin K deficiency

Hemorrhagic disease of the newborn can happen because of sterile intestines of newborn, so routing intramuscular injection of Vitamin K for all newborns; in adults seen in patients with fat alabsoprtion and prolonged used of broad spectrum antibiotics, leads to hematuria, bruises, bleeding gums 427

Calcitonin

Hormone produced in the thyroid; takes calcium from the blood and puts it in the bones; works in balance with PTH to maintain homeostasis of calcium 415

Magnesium is a major mineral.

Magnesium is a major mineral. 1. Magnesium has several important functions. a. Magnesium is one of the minerals that make up the structure of bone. b. Magnesium helps regulate bone and mineral status. c. Magnesium is a cofactor for over 300 enzymes. d. Magnesium is necessary for ATP production. e. Magnesium plays an important role in DNA and protein synthesis. f. Magnesium supports normal vitamin D metabolism. g. Magnesium is necessary for normal muscle contraction and blood clotting. 2. How much magnesium should we consume? a. People who are adequately nourished generally consume adequate magnesium. i. The RDA changes with age and gender. b. What are good food sources of magnesium? i. Magnesium is found in seafood and green leafy vegetables. ii. Magnesium is found in whole grains, seeds, and nuts. iii. Refined and processed foods are low in magnesium. 3. What happens if we consume too much magnesium? a. Toxicity from supplements may include diarrhea, nausea, and abdominal cramps. b. Individuals with impaired kidney function who consume excessive nondietary magnesium suffer from hypermagnesemia. 4. What happens if we don't consume enough magnesium? a. Magnesium deficiency can result in low blood calcium. b. Magnesium deficiency can result in muscle cramps and seizures. c. Magnesium deficiency can result in nausea. d. Magnesium deficiency can result in irritability and confusion. e. Long-term magnesium deficiency is associated with osteoporosis and other chronic diseases.

Vitamin D food sources

Milk, Liver, Butter, Eggs, Fatty Fish 423

Osteoporosis

Osteoporosis Is the Most Prevalent Disorder Affecting Bone Health. A. Osteoporosis is a disease characterized by low bone mass and deterioration of bone tissue. 1. Osteoporosis is the single leading cause of hip and spinal fractures. B. Aging impacts osteoporosis risk. 1. Bone density declines with age. 2. Hormonal changes have a significant impact on bone loss. 3. Decreased ability to metabolize vitamin D exacerbates bone loss. C. Gender and genetics affect osteoporosis risk. a. 80% of Americans with osteoporosis are women. b. Women are more likely to participate in eating disorders than men. c. A family history of osteoporosis increases risk. D. Smoking and poor nutrition increase osteoporosis risk. 1. Cigarette smoking decreases bone density. 2. Chronic alcoholism is associated with high rates of fracture. 3. Excess caffeine consumption may be detrimental to bone health in older adults. 4. High sodium intakes increase the excretion of calcium. 5. High protein intakes have been shown to have both a negative and a positive impact on bone health. 6. Many nutrients are important for bone health, especially calcium and vitamin D. E. Physical activity impacts osteoporosis risk. 1. Regular weight-bearing excerise is highly protective against bone loss and osteoporosis. 2. The female athlete triad is a condition characterized by the coexistence of three disorders in some athletic females: a. an eating disorder b. amenorrhea c. osteoporosis F. Treatments for osteoporosis can slow and even reverse bone loss. 1. Consume adequate calcium and vitamin D. 2. Exercise regularly. 3. Antiresorptive drugs are available that slow bone resorption. 4. Hormone replacement therapy can help prevent osteoporosis. 5. Alendronate and resedronate are drugs approved for prevention and treatment. 6. Other medications mimic the effects of estrogen and slow bone loss.

Phosphorus

Phosphorus is the major intracellular negatively charged electrolyte. 1. Phosphorus has several important functions. a. Phosphorus is part of the mineral complex of bone. b. Phosphorus plays a role in fluid balance. c. Phosphorus is a primary component of ATP. d. Phosphorus helps activate and deactivate enzymes. e. Phosphorus is a component of DNA and RNA. f. Phosphorus is a component of cell membranes and lipoproteins. 2. How much phosphorus should we consume? a. The RDA for phosphorus is 700 mg per day. b. What are good food sources of phosphorus? i. Phosphorus is widespread in many foods and is found in high amounts in protein-containing foods. ii. Phosphorus is found in many foods as a food additive. iii. The phosphorus in soft drinks was theorized to negatively affect bone health. a. Recent studies indicate that phosphorus in soft drinks does not increase calcium loss. b. Displacing calcium-containing beverages with soft drinks is probably the reason bone health is affected by their consumption. 3. What happens if we consume too much phosphorus? a. Severely high blood phosphorus can cause muscle spasms and convulsions. 4. What happens if we don't consume enough phosphorus? a. Phosphorus deficiencies are rare but can occur with certain medical conditions.

Vitamin D

Promotes growth and health of bones excess stored in adipose and liver 421

Menaquinone

The form of vitamin K produced by bacteria in the large intestine. 425

Vitamin D is a fat-soluble vitamin and a hormone.

Vitamin D is a fat-soluble vitamin and a hormone. 1. Vitamin D can be made from a cholesterol compound when the skin is exposed to UV light. 2. Vitamin D works with PTH and calcitonin to regulate blood calcium levels. a. They regulate absorption of calcium and phosphorus from the small intestine. b. They signal the kidneys to excrete more or less calcium in urine. c. Vitamin D and PTH stimulate osteoclasts when calcium is needed elsewhere in the body. 3. Vitamin D assists in the normal calcification of bone, prevents growth of some cancers, and plays a role in cell differentiation. 4. How much vitamin D should we consume? a. The AI is based on the assumption that an individual does not get adequate sunlight. i. The AI for adults is 5 g per day. ii. The UL is 50 g for all ages. b. What are good food sources of vitamin D? i. Milk is fortified with vitamin D. ii. Fatty fish and cod liver oil are good sources of vitamin D. iii. Some cereals and soy products are fortified with vitamin D. 5. What happens if we consume too much vitamin D? a. Sun exposure cannot cause vitamin D toxicity. b. Toxicity symptoms can occur when supplementing with as little as five to ten times the AI. i. Hypercalcemia results from overconsuming vitamin D and causes: a. weakness b. loss of appetite c. diarrhea d. mental confusion e. vomiting f. excessive urine output g. extreme thirst h. calcium deposits in soft tissues i. increased bone loss 6. What happens if we don't consume enough vitamin D? a. The primary symptom of vitamin D deficiency is loss of bone mass or demineralization of bone. i. Diseases that cause intestinal malabsorption of fat often lead to vitamin D deficiency. ii. Rickets is a vitamin D-deficiency disease in children. iii. Osteomalacia is a vitamin D-deficiency disease in adults. iv. Osteoporosis can result from vitamin D deficiency.

Vitamin K

Vitamin K, a fat-soluble vitamin, is a family of compounds known as quinones. 1. Vitamin K serves as a coenzyme in the production of specific proteins. a. Vitamin K assists in production of prothrombin, which is necessary for blood clotting. b. Vitamin K assists in production of osteocalcin and matrix Gla protein, two proteins associated with bone turnover. 2. How much vitamin K should we consume? a. In addition to the vitamin K obtained from food, it is produced by the bacteria in the large intestine. b. AI is 120 micrograms per day for adult men and 90 micrograms per day for adult women. c. What are good food sources of vitamin K? i. Green leafy vegetables are good sources of vitamin K. ii. Vegetable oils such as soybean and canola oil are good sources of vitamin K. 3. What happens if we consume too much vitamin K? a. There appear to be no side effects associated with consuming excessive vitamin K. 4. What happens if we don't consume enough vitamin K? a. Vitamin K deficiency is associated with a reduced ability to form blood clots. b. Vitamin K deficiency may affect bone health, but the relationship is not clear.

T score

a comparison of an individual's bone density to the average peak bone density of a 30-year-old healthy adult 413

cortical Bone / compact Bone

a dense bone tissue that makes up the outer surface of all bones as well as the entirety of most small bones of the body 80% of skeleton 410

Vitamin K

a fat-soluble vitamin that helps in the clotting of blood stored primarly in liver quinones Pnylloquinone - plants Menaquinone - bacteria in large intestine 425

Collagen

a fibrous scleroprotein in bone and cartilage and tendon and other connective tissue 410

Dual energy x ray absorptiometry

a noninvasive procedure that measures bone density DEXA 413

Fluorosis

a pathological condition resulting for an excessive intake of fluorine (usually from drinking water) 432

Osteoporosis

abnormal loss of bony tissue resulting in fragile porous bones attributable to a lack of calcium 80% with O are women 432

Osteomalacia

abnormal softening of bones caused by deficiencies of phosphorus or calcium or vitamin D 424

Amenorrhea

absence or suppression of normal menstrual flow 435

Female athlete triad

amenorrhea, osteoporosis, and eating disorders; when left untreated they damage the musculoskeletal and reproductive systems 435

Hypermagnesemia

an excess of magnesium in the blood plasma 430

Bone growth

appostitional growth through periosteum and endosteum. No interstitial growth. 411

Calcium function

bone and teeth formation, Blood clotting, muscle contraction, nerve transmission, cell wall permeability, enzype regulator 414

osteoblasts

bone forming cells 412

Rickets

childhood disease caused by deficiency of vitamin D and sunlight associated with impaired metabolism of calcium and phosphorus 424

Hypomagnesemia

deficiency of magnesium in the blood plasma 430

DXA

dual-energy absorptiometry 413

osteoporosis treatments

estrogen replacement therapy (ERT) slows bone resorption, but increases risk of breast cancer, stroke and heart disease drugs Fosamax/Actonel destroys osteoclasts PTH slows bone loss if given as daily injection Forteo (PTH derivative) increases density by 10% in 1 year may promote bone cancer so use is limited to 2 years best treatment is prevention - exercise and calcium intake (1000 mg/day) between ages 25 and 40 436

Fluoride toxicity

fluorosis- changes to bone, kidney, muscle function. Dental fluorosis- mottling of teeth. Death: 32-64 mg fluoride/kg. Upper limit - 1.3 mg/d for children ages 1-3 432

Osteoporosis Risk factors

genetics; female; caucasian; low calcium intake; small bones; sedentary; post-menopausal table 433

Calcium Rigor

hardness or stiffness of the muscles caused by high blood calcium concentrations 416

Trabecular bone

inside of bone, aka spongy or cancellous, composed of thin processes or fingers of bone tissue, contain osteons 20% of skeleton 411

Calcium Tetany

intermittent spasm of the extremities due to nervous and muscular excitability caused by low blood calcium concentrations 415

Calcium overconsumption

leads to hypercalcitonism abnormal endochondrol ossification 418

Bone modeling

mechanism by which bones maintain their shape and proportions as they grow 411

Phosphorus function

mineralization of bones and teeth; part of phospholipids; important in genetic materials; used in energy metabolism and in buffer systems that maintain acid-base balance 427

Phosphorus over dose

muscle spasm conculsions 428

Vitamin K overconsumption

no side effects 427

Magnesium toxicity

none from foods but some from supplements - diarrhea and dehydration. ul is 350 mg/day 430

Vitamin K function

production of bone proteins "GLA" proteins osteocalcin secreted by osteoblasts associatedwith bone remodeling Matrix Gla protein in protein matrix of bone, found in cartilage, blood vessel walls and other soft tissues 426

Remodeling

results from combined action of the bone-dissolving osteoclasts and the bone-depositing osteoblasts 412

Calcitriol

steroid hormone secreted by the kidneys when parathyroid hormone is present; stimulates the absorption of calcium and phosphate in the digestive tract 421

Bone density

the degree of compactness of bone tissue, reflecting the strength of the bones. the peak is the point at which a bone is strongest 411

Phylloquinone

the form of vitamin k found in plants 425

Hypercalcemia

the presence of abnormally high levels of calcium in the blood 418

Resorption

the process by which the surface of bone is broken down by cells called osteoclasts 412

Bioavailability

the rate at and the extent to which a nutrient is absorbed and used 416

Phosphorus

this is an electrolyte. Has opposite effect of calcium. Too much causes ventricular dysrthmias & cardiac arrest. Too little causes conduction problems, T & B-cardia. NORMAL 2.7 - 4.5 427

Vitamin D overconsumption

toxicity; nausea, loss of appetite, kidney damage, deposits of insoluble calcium salts in tissue 423

Calcium deficiency

yields osteoporosis in later years or rickets in children and and osteopenia in young people 419