Chapter 9: bone health

Question 1

what is the organic structure in bone?

Answer 1

collagen

Question 2

what is the composition of bone?

Answer 2

35% organic structures (collagen), 65% minerals (hardness)

Question 3

cortical bone

Answer 3

very dense tissue, outer surface of all bones, 80% of skeleton

Question 4

trabecular bone

Answer 4

“scaffolding” on the inside of bones”, supports cortical bone, 20% of skeleton

Question 5

which type of bone is more sensitive to nutritional deficiencies and why?

Answer 5

trabecular bone because it has a faster turnover rate

Question 6

osteoclasts function

Answer 6

erode surface of bones (resorption) to release calcium into blood & repair bone or obtain minerals to repair another bone

Question 7

osteoblasts function

Answer 7

(formation) produce the collagen-containing component of bone (hydroxyapatite)

Question 8

hydroxyapatite composition

Answer 8

calcium and phosphorus

Question 9

what happens around age 40 for women that causes them to lose bone density?

Answer 9

menopause

Question 10

when is peak bone health achieved?

Answer 10

age 30

Question 11

what machine measures bone density

Answer 11

DEXA

Question 12

osteoporosis is characterized by?

Answer 12

low bone mass/density (common in hip and spine), hip fractures common, gradual compression fractures in spine

Question 13

symptoms of osteoporosis

Answer 13

no early symptoms

Question 14

what are some modifiable risk factors for osteoporosis?

Answer 14

low body weight, low calcium intake, low sun exposure, alcohol abuse, smoking, amenorrhea (with recognizable cause), estrogen or testosterone deficiency in females and males respectively, sedentary lifestyle

Question 15

what are some nonmodifiable risk factors for osteoporosis?

Answer 15

older age, caucasion or asian, family history of osteoporosis, gender (female), amenorrhea (with no cause)

Question 16

what sort of diet is associated with improved bone health?

Answer 16

diet high in fruits and veggies

Question 17

what kind of exercises stress bones, leading to increased bone mass?

Answer 17

weight-bearing activities such as walking, jogging

Question 18

progression of osteoporosis may be slowed by?

Answer 18

adequate calcium & vitamin D intake, regular exercise, some medications

Question 19

what is the goal for bone density in terms of preventing osteoporosis?

Answer 19

maximize bone density before age 30, maintain bone density after age 30

Question 20

functions of calcium

Answer 20

forms and maintains bone and teeth structure, assists with acid-base balance, transmission of nerve impulses, assists in muscle contraction

Question 21

is calcium a major or trace mineral? where is it found in the body?

Answer 21

most abundant major mineral, 99% found in bone

Question 22

what vitamin helps correct the blood calcium range?

Answer 22

vitamin D

Question 23

what two things does calcium bioavailability depend on?

Answer 23

age and need

Question 24

what percent of calcium do healthy adults typically absorb?

Answer 24

30%

Question 25

which groups have a higher absorption percentage of calcium compared to healthy adults?

Answer 25

infants, children, adolescents, pregnant & lactating women

Question 26

which groups have a lower absorption percentage of calcium compared to healthy adults?

Answer 26

older adults

Question 27

maximum amount of Ca absorbed at one time?

Answer 27

500 mg

Question 28

as more calcium is consumed, what happens to absorption?

Answer 28

% absorbed decreases

Question 29

consuming calcium with what may decrease absorption?

Answer 29

oxalates and phytates

Question 30

what is required for calcium absorption?

Answer 30

vitamin D

Question 31

calcium sources

Answer 31

dairy products, leafy green vegetables, calcium fortified foods

Question 32

what happens if you consume too much calcium? too much calcium from calcium supplements?

Answer 32

excess calcium is excreted from the body, excess calcium from supplements can lead to mineral imbalances

Question 33

what is hypercalcemia caused by?

Answer 33

cancer and overproduction of PTH

Question 34

hypercalcemia can cause what?

Answer 34

organ failure because of calcium deposits

Question 35

what should we avoid in calcium supplements?

Answer 35

bone meal, oyster shell, dolomite because they may contain lead

Question 36

is vitamin D fat soluble or water soluble? how is it synthesized?

Answer 36

fat soluble, synthesized in the body by exposure to UV light from sun

Question 37

functions of vitamin D

Answer 37

required for calcium and phosphorus absorption, stimulates osteoclasts, necessary for calcification of bone, regulates blood calcium levels

Question 38

groups of people living where may receive inadequate sun exposure from mid-October to mid-March?

Answer 38

northern latitudes

Question 39

is there an RDA for vitamin D?

Answer 39

yes, it is set for people who do not get enough sun exposure

Question 40

sources of vitamin D in foods?

Answer 40

most foods contain very little vitamin D naturally, most come from fortified foods and supplements (canned salmon, canned mackerel, milk, cheerios)

Question 41

what does too much vitamin D result in? how does it result?

Answer 41

vitamin supplements, not from excessive exposure to sun -> hypercalcemia

Question 42

what may result from vitamin D deficiency?

Answer 42

rickets or osteomalacia

Question 43

rickets

Answer 43

bone deformities and impaired growth in children

Question 44

osteomalacia

Answer 44

occurs in adults, bone pain or tenderness

Question 45

what kind of mineral is fluoride and where is it found in the body?

Answer 45

trace mineral; 99% found in teeth and bones

Question 46

functions of fluoride

Answer 46

development and maintenance of teeth and bones, makes fluorohydroxyapatite (fluoride, phosphorus, and calcium) makes tooth enamel stronger, resistant to acids and bacteria

Question 47

sources of fluoride

Answer 47

fluoridated dental products, fluoridated water (tap)

Question 48

what happens if you have too much fluoride?

Answer 48

fluorosis: creates porous tooth enamel, teeth become stained and pitted

Question 49

what happens if you don't consume enough fluoride?

Answer 49

cavities