Calcium

Question 1

What is the UL for Ca?

Answer 1

2500mg

Question 2

how much do you need a day to balance Ca lost in bone resorption?

Answer 2

250mg

Question 3

if you have enough Vit D, you absorb ___

Answer 3

30% of 800 mg (the EAR)

Question 4

passive absorption is about ___%

Answer 4

10

Question 5

what proteins are involved in transport of Ca across the BBM?

Answer 5

Calbindin, Ca channels (TRPV6)

Question 6

Passive transport involves ____ transport and diffusion

Answer 6

paracellular

Question 7

What are inhibitors of calcium absorption?

Answer 7

other divalent cations (not from normal diet), unabsorbed f.a. that bind to Ca to make insoluble soaps, fibre, oxalic/phytic acid (bind divalent cations)

Question 8

what are the three sites that PTH acts on during hypocalcemia?

Answer 8

bone (resorption=loss), kidney (reabsorption, ^1,25), small intestine (absorption)

Question 9

what is the counter-hormone to calcitriol?

Answer 9

calcitonin (not much clinical importance)–>released after you eat

Question 10

What is bone mineral called?

Answer 10

hydroxyapatite

Question 11

Bone that is compact/dense, majority of bone in body, consists of collagen layers, found mainly on surfaces of all bones and as shaft of long bones

Answer 11

cortical bone

Question 12

Type of bone that is spongy, where Ca is taken out from, matrix of collagen, found in axial skeleton and the ends o bones

Answer 12

trabecular bone

Question 13

_____improve Ca solubility in the GI

Answer 13

Vitamin D, protein, sugars, sugar alcohols (fermented to acid)

Question 14

What are nutrients that enhance urinary calcium excretion and decrease efficiency of reabsorption?

Answer 14

sodium, protein, caffeine

Question 15

what nutrients are inhibited by excessive calcium?

Answer 15

phosphorus, iron, f.a.

Question 16

____ prefers calcium, ___ prefers zinc

Answer 16

oxalate; phytate (found in cell walls)

Question 17

insoluble soaps (f.a.+Ca) might protect against ____

Answer 17

colon cancer

Question 18

Why is spinach calcium poorly absorbed?

Answer 18

because it contains oxalate

Question 19

approximately ___ % of plasma Ca is reabsorbed by kidney nephrons

Answer 19

98 (PTH ^ reabsorption efficiency)

Question 20

how does excess protein cause ^ acid production?

Answer 20

Cystein and Methionine produce H2SO4

Question 21

what is the RDA? What s the EAR?

Answer 21

1000mg; 800mg

Question 22

what are the two ways to measure calcium balance?

Answer 22

in=out; DXA (dual xray absorpiometry)–>change in bone mineral amount over time

Question 23

amenorrhea is associated with

Answer 23

anorexia nervosa

Question 24

the UL for Ca is set to prevent this

Answer 24

kidney stones

Question 25

What is the LOAEL?

Answer 25

2000 mg

Question 26

condition of soft tissue calcification

Answer 26

milk-alkali syndrome

Question 27

high intakes of Ca pose controversial risk of ___ and ____ in men

Answer 27

heart disease; prostate cancer