nutrition Ch 11

excessive calcium intakes

kidney stones, irritability, and kidney failure

where does vitamin D act to regulate blood calcium levels

kidney, bone, and intestine

vertebral fractures that may result in abnormal curvature of the upper spine

kyphosis

trabecular bone

lattice-like bone tissue that acts to absorb shock, houses bone marrow, and provides structure and stability

average adult consumption of magnesium

less that he/she needs

oxalates

limits bioavailability of calcium from that food, but not the absorption of calcium from other foods

large amounts of phytic acid (grains, excess phosphorus, polyphenols in tea)

limits calcium absorption

bone resorption

loss of bone mineral density and release of calcium, phosphorus, and magnesium into the blood

osteopenia

low bone mineral density

overuse of laxatives or antacids

magnesium toxicity

minerals that play a role in bone strength

magnesium, calcium, and phosphorus

goal of preventing osteoporosis

maintain regular menstruation, meet dietary needs of calcium and protein

calcium absorption increased by

pregnancy, presence of glucose and lactose in the diet, and high blood levels of parathyroid hormone

bisphosphonates

prevent bone loss by limiting osteoclast activity

phosphorus

second most abundant mineral in the body

periosteum

thick membrane that covers the bone surface that is found on the outer surface of bones and is connected to muscle, tendons, and ligaments

milk is a very good source of phosphorus

true

percentage of vitamin D needs met by exposure to sunlight

80%

8c of cooked spinach

= 1 c of milk in calcium

lowest to highest amounts of magnesium

1- whole wheat bread, 2- banana, 3- plain yogurt, 4- spinach

lowest calcium per serving

1/2 c cottage cheese

UL for vitamin D

100 micrograms daily

UL of fluoride for adults

10mg per day

daily sunlight exposure

15 min per day

UL (upper level) for calcium for healthy 24yr old female

2500mg per day

UL for phosphorus

3-4g per day

AI for fluoride per day

3.1-3.8 mg/day

on average, peak bone mass is achieved around what age

30

should undergo DEXA testing

63 year old woman who takes steroids for arthritis pain and 47 year old peri-menopausal woman who suffered a stress fracture in her wrist

at risk for developing osteoporosis

Asian and Caucasian

DRI for young men

Calcium- 1000 milligrams phosphorus- 700 milligrams vitamin D- 15 mircograms magnesium- 400 milligrams fluoride- 3.8 milligrams

Diary products (such as milk and cheese) provide about 25% of calcium in American diets

False- 75%

The low absorption, plus limited availability of phosphorus in foods makes this mineral more important than calcium in diet planning

False- high absorption, plus wide availability in foods, makes this mineral less important than calcium in diet planning

RDA for magnesium (400mg for men/310 for women)

True

adults absorb about 30% of calcium in foods, but that increases to about 60% during infancy and pregnancy

True

commonly occurs in women after menopause as a result of low estrogen concentrations

Type 1 osteoporosis

bone-building nutrient/hormone

Vitamin D

Vitamin D synthesis

Vitamin D synthesized on sunny days can be stored for use during times of limited sun exposure and optimal skin synthesis of vitamin D occurs between 10a-3p

aging in healthy individuals

a loss of bone mass and a decrease in bone mineral density

exercise is beneficial for bone health

because the additional stress on bone increases bone mineral density

bone remodeling

continual balance of degradation and resynthesis of bone by osteoclasts and osteoblasts

typically calcium intake falls short

adolescent girls, young adult women, and older men

type 2 osteoporosis

affects both men and women, demineralization of trabecular and cortical bone

factors that may effect vitamin D synthesis by skin

age, skin pigmentation, and latitude

at risk for marginal phosphorus status

alcoholics, older adults with nutrient-poor diets, pre term infants

UL of 350mg/day of magnesium

antacids, supplements, and laxatives

Adequate dietary intake of magnesium

associated with decreased risk of Cardiovascular disease and type 2 diabetes

trabecular bone demineralizes more rapidly than cortical after menopause

because trabecular bone has higher density of osteoblast and osteoclast cells and osteoblast activity decreases, but osteoclast activity remains high

83 yrs old- irregular meals/skips meals and gastric reflux

best supplement is calcium citrate

functions of calcium

bone building, muscle function, and blood clotting

who benefits supplements containing vitamin D

breastfed infants, total vegetarians, people with fat malabsorption

Vitamin D hormone affects bone metabolism

by aiding in depositing calcium in the bones and regulating intestinal absorption of calcium

small intestine

most acidic portion

a mineral mainly stored in bones and teeth

calcium

excessive Vitamin D intake

calcium deposits in organs and gastrointestinal disorders

forming and maintaining bones

calciums major role in the body

magnesium and potassium

can decrease blood pressure and prevent heart rhythm abnormalities

stromal cells in bone marrow

can develop into cartilage cells, bone cells, and fat cells

imbalance in calcium-to-phosphorus ratio

causes bone loss

body processes that rely on phosphorus

cell division, cell membrane transport, and energy metabolism

prevention of osteoporosis

conducting weight bearing exercises, consuming a diet rich in calcium and vitamin D, and maintaining a healthy body weight

medications that decrease bone mineral density

cortisol, diuretics, and thyroid hormones

attaining higher peak bone mass

decreases the risk of ultimately developing osteoporosis

tetany

deficiency of magnesium and calcium

cortical bone

dense bone tissue that provides strength and stability

blood cells

derived from hemopoietic cells in the bone marrow

smoking

detrimental to bone health

National Osteoporosis Foundation- women ages 65-70 to assess bone health

dual energy x-ray absorptiometry

hip, spine, and wrist are common sites for fractures

due to being high in trabecular bones

menopause may lead to rapid loss of bone mass

due to estrogen being required for maximal osteoblast activity

higher bone mineral density at 25 predictive of better bone health at age 65

due to minerals providing strength and structure to withstand fractures and beginning adulthood with high bone mineral density lessens the impact of inevitable age related bone loss

vitamin D content (lowest to highest0

egg yolk, soy milk, skim milk, baked salmon

active vitamin D

enhances absorption of calcium and phosphorus

if calcium intake is inadequate

excessive intake of phosphorus, sodium, and caffeine may negatively impact bone mineral density

trace mineral that contributes to bone health

fluoride

bone is the major depot for what bone-building nutrients

fluoride, phosphorus, magnesium, and calcium

poor magnesium status

found among use of certain diuretics

functions of fluoride

helping teeth resist acids, mineralizing tooth enamel, and blocking growth of bacteria

body weight in relation to bone mass

higher body weight tends to increase bone mass due to extra stress on bone

populations naturally high in fluoride

higher rate of tooth mottling and lower rate of dental caries

fat-free milk

highest milligrams of calcium per kcal- most nutrient dense source of calcium

risks of developing rickets

inadequate vitamin D intake and cystic fibrosis

attaining lower peak bone mass

increases risk of ultimately developing osteoporosis

American Academy of Pediatrics

infants should obtain 10 micrograms (400 IU) of Vitamin D daily

boron

influences calcium transport and vitamin D synthesis

marginal phosphorus status

may be a concern is nutrient intake is low or high supplemental calcium intake competes with phosphorus for absorption

vertebral fractures that cause the spine to curve

may lead to loss of height, mobility problems, and impaired lung function

rich sources of phosphorus

milk, cheese, meat, and bread

a person with darker skin

needs LONGER to synthesis vitamin D from sunlight

oxalic acid

organic acid found in dark leafy green vegetables that can depress absorption of certain minerals

in the process of bone remodeling, bone cell synthesis is accomplished by which type of cell

osteoblasts

osteoblasts that become embedded into the bone matrix, where they synthesize bone tissue

osteocytes

many older adults have low bone mineral density before diagnosed with osteoporosis

osteopenia

T-sourse

osteopenia- -1.8 normal- -.5 osteoporosis- -2.7

decreased bone mass related to the effects of aging, genetic background, and poor diet in both genders

osteoporosis (debilitating, about 1.5 million bone fractures per year, and costs 17 billion a year

ethnicity and bone health

people of Asian descent are at increased risk of poor bone health

portable and efficient techniques for measuring bone mineral density

peripheral quantitative computed tomography and peripheral DEXA

least likely to be deficient in American diets

phosphorus

osteomalacia

poor intestinal absorption and kidney disease

type 2 osteoporosis

porous trabecular and cortical bone in men and women that occurs after age 60

type 1 osteoporosis

porous trabecular bone in women that occurs following menopause

potassium

promotes alkaline environment of blood, thus preventing withdrawal of bone minerals as buffers

macronutrient important for synthesis, maintenance, and repair of bones

protein

deficiencies of phosphorus

rare because the mineral is widespread in the diet and because the mineral is efficiently absorbed

Bone remodeling- osteoclasts

release minerals into the blood and break down bone tissue

vitamin K

required for binding of calcium to bone proteins

Vitamin C

required for synthesis of connective tissue in bone

hip fractures

result in loss of independence, mortality, and disability

factors that affect conversion of sunlight to vitamin D

skin color and age

sources of vitamin D

skin from sun exposure, fatty fish, and fortified foods

bone marrow

spongy bone tissue that contains stem cells

alternative forms of calcium

tofu, sardines, and fortified soy milk

high levels of ingested fluoride

tooth mottling and skeletal damage

how does alcoholism affect bone health

toxic to bone cell and increases urinary excretion of magnesium

bone most dramatically affected when osteoclast activity exceeds osteoblast activity

trabecular

most susceptible to biological and lifestyle factors that affect bone health

trabecular bone

rickets

vitamin D deficiency characterized by bowed legs, enlarged head, deformities of the ribs and pelvis, and pain in the joints

key nutrients required for synthesis, maintenance, and repair of bones

vitamin D, protein, fluoride, calcium, magnesium, and phosphorus

DEXA measures the ability of bone to block low-levels to determine bone mineral density

x-ray