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