Calcium Flashcards
Blood Ca changes due to
to abnormal regulatory control; NOT DIET
Increase in blood Ca causes
Ca Rigor; muscle contract; cannot relax
Decrease in Blood Ca
Ca Tetany; uncontrolled muscle contraction
Ca Rigor + Ca Tetany is caused by
changes in abnormal regulatory control; NOT DIET
Long Term inadequate Ca intake is reflected in
BONES not blood
How much % is Ca absorbed
25-30 % normally. 50% in children. teens, pregnant women
What protein is needed to increase Ca absorption?
Ca binding protein
Vitamin that is needed for production of Ca binding protein
Vitamin D
Milk is best for what Vitamin production
Vitamin D
What inhibits Ca abs. ?
lack of stomach acid, High P, vit D. deficiency, high fiber diet, Oxalates, and Phytates
Phytates
seeds, nuts & grains
Oxatales
beets, rhubarb, and spinach
What is needed to enhance ca abs?
Stomach Acid
Vitamin D
Lactose
Growth hormones
Hormones involved in Ca homeostasis?
Vitamin D
parathormone
Calcitonin
How does Vitamin affect the abs. of Ca in the intestines?
-Increases production of intestinal Ca transport genes
-MAKES Ca binding protein to increase abs.
Where is Ca binding protein made?
intestines
When Blood ca decreases what hormone is released ?
Parathyroid hormone PTH is released; stimulates kidneys to convert 25 hydroxy vit D to 1,25 hydroxy vit. D
Vitamin D decreases CA excretion via Kidneys
because the blood is low on Ca; Vitamin d Will tell the kidneys to stop excreting
What hormone stimulates kidneys to convert 25 hydroxy vit D to 1-25 hydroxy vit. d ?
Parathyroid hormone PTH
When does the hormone Parathyroid Hormone PTH signal the kidneys?
When blood Ca levels drop
What is osteoclasts ?
Blood Ca is low; therefore vit. D causes cells to convert into bone DISSOLVING cells to release Ca in the blood
cells from bones need to DISSOLVE to go into the blood
What is osteoblasts?
Blood Ca is high; cells need to convert to bone making cells
from BLOOD TO BONE to reduce blood ca
How does Vitamin d act like a hormone?
When Ca abs. needs to be increased it stimulates intestines to make ca binding protein
When Ca blood is low it will let the kidneys know to stop excreting Ca; PTH gets released.
Vitamin D signals the precursor cells to either to convert either osteoblasts or osteoclasts.
When there is an increase in Ca in the blood the Thyroid gland secretes
Calcitonin - atone wants to stop everything
prevents activation of Vitamin D
prevents reabs. of ca by kidneys
Limits Ca abs. by intestines
inhibits bone breakdown
What hormone gets released when there is an increase of Ca?
Calcitonin
What would you need to lower blood Ca levels?
Calcitonin
Prevents vit. D from communicating to organs involved needed for abs.
prevents reabs. of ca by kidneys
limits ca abs. by intestines
inhibits bone breakdown
How to increase blood Ca levels?
Vitamin D needed to signal intestines, kidneys, bones
when blood drops it signals the Parathyroid to release Parathormone -
*Parathormone will activate Vit. D
Vit. D & parathormone stimulate Ca reabs. in the kidneys
Vit D signals intestines to to increase Ca abs.
Vit. D will stimulate bone to release Ca
Rising blood Ca levels will signal Thyroid gland to secrete what?
Calcitonin
Failing blood Ca levels will signal Parathyroid to secrete
parathormone
Adolescents up to age 18; 1,300 mg Ca/day 2,500 mg Ca/day
Adolescents up to age 18; 1,300 mg Ca/day 2,500 mg Ca/day
3 cups of milk; 1300 mg
Adults age 19-50; 1,000 mg Ca/day 2,500 mg Ca/day
Adults age 19-50; 1,000 mg Ca/day 2,500 mg Ca/day
Lowest
Adults age 50 or older; 1,200 mg Ca/day 2,500 mg Ca/day
Adults age 50 or older; 1,200 mg Ca/day 2,500 mg Ca/day
Men need less than women
Women age 50 or older ; 1,500 mg Ca/day 2,500 mg Ca/day
Women age 50 or older ; 1,500 mg Ca/day 2,500 mg Ca/day
They need the most
How many cups of milk for children?
2 cups
How many cups of milk for teenagers?
3 cups
How many cups of milk for adults ?
2 cups
How many cups of milk for pregnant or lactating women?
3 cups
for teens 4 cups
Non Ca sources
tofu corn tortillas bread bok choy kale brocolli seaweeds, oysters small fish, soneardines
foods that contain Ca binders
spinach; swiss chard
Consequences of not drinking enough milk during childhood & adolescence that persist into adulthood
lower bone density; fractures
foods > 50 % absorbed
Cauliflower, watercress, brussel sprouts, rutabaga, kale, mustard greens, bok choy, broccoli, turnip greens, calcium fortified foods, beverages,
=30 %
Milk, calcium fortified soy, calcium set tofu, cheese, yogurt
=20%
Almond sesame seeds, pinto beams, sweet potatoes
<5%
spinach rhubarb swiss cheese
Peak Bone Mass
highest attainable bone density develops for the first 3 decades of life
What age do adults lose bone ?
After the age of 40
What age is peak bone mass achieved?
19-30 yrs old
osteopenia
people with moderate degree of bone mass reduction; increased risk of fractures
Cortical bone
dense bone tissue; outer hard shell; confers strength; gives up ca slowly; losses begin at the age of 40; loses continue and slowly
Trabecular
lacy network of ca-containing crystals that fills the interior
Cortical bone *
dense ivory like bone that forms the exterior shell; ca storage bank; metabolically active
What ages do you experience loses of Cortical Bone; Trabecular bone
40 cortical; 30 Trabecular
Type 1 Osteo
-Postmenopausal
-50-70 yrs
-Trabecular bone
-Spine; wrists
-vertebrae designates pinching down nerves
-teeth will fall out
-women out number men 6:1
-loss of estrogen; testosterone
Type 2 Osteo
=70 or older
ca withdrawn from C & T bone
HIP
Results from reduced calcium absorption, increased
bone mineral loss, increased propensity to fall
2:1
what % do hip fractures occur in the US
90% occur over the age of 50
2 major stages in life critical in the
development of osteoporosis
- Childhood & adolescence when the bones gain strength and density.
- Late adulthood (women after menopause): osteoblasts are less active, but osteoclasts (dismantle bone) are more active. Bone loss exceeds formation & results in osteoporosis.
AGE:how to max bone mass with age?
Maximizing Bone Mass
–Adequate supply of Ca & vi D during the first 3 decades of life.
–When reaching older age, higher bone density gained earlier will remain.
AGE: Minimizing Bone Loss
–Dietary intake of Ca is usually lower.
–Kidneys do not activate vit D as well, less time outdoors.
–The hormones regulating Ca metabolism deteriorate,
resulting in bone loss.
Genetics:
- Influential role in bone density:
- peak bone mass achieved during growth
- extent of bone loss rate in later years
- bone density is also influenced by diet,
physical activity, alcohol, tobacco abuse
- bone density is also influenced by diet,
- The extent to which genetic potential is realized
depends on diet, physical activity, hormones,
smoking, alcohol
Race
African-Americans use and conserve Ca more efficiently
than Caucasians.
- Black people have denser bones, in spite of lower Ca intakes
and lower osteoporosis and fractures (3x less). - Asians, Hispanics have lower bone density, but also lower
rates of fractures. They may have smaller, more compact
hips, which makes them less susceptible to fractures. - Genetic factors alone do not determine risk of osteoporosis.
Adaptation to low Ca intakes (higher absorption) and other
environmental factors play a role.
Factors influencing balance of Ca deposits vs. withdrawals:
nutrition during the first 3 decades of life
( Ca + vit D)
* when bones have high density they can lose more Ca
Ca absorption decreases often after the age of
65
Minimizing Bone loss
Ca absorption decreases often after the age
of 65.
* Ca and vit D intakes low in elderly.
* Hormones regulating Ca balance decrease:
- Vitamin D less efficiently activated,
- Parathormone calcitonin, estrogen
levels are reduced.
* These changes favor bone Ca removal.
