Pharma principles of Ca and skeleton Flashcards
what is minimal intake of Ca to not lose
5 mmol/day
at waht point does Ca absorbtion plateau
25 mmol/day (1000mg)
what is best absorption dose of Ca
500 mg
what are 2 supplement forms of Ca
- Ca carbonate - requires food and needs acid
2. Ca citrate - easier to absorb
how does vit D impact Ca
increases Ca binding protein and thus increases uptake
how much of dietary Ca is absorbed
about 1/3
how is Ca bound in ECF
40% protein bound
10% complexed to other ions
50% ionized (available portion)
how much Ca is reabsorbed in urine
98%
4 factors influencing Ca excretion
- PTH - 10% of Ca reabsorb
- protein and Na levels in diet
- thizide diuretic incr. Ca absorb
- loop diuterics increase Ca excretion
what are forms of most vit D
D2 and D3 - not yet active, need to be catalysed
why does Vit D require fat
fat souble, needs fat for absobtion
where is vit D metabolised
- liver to 25D
2. kidney to 1,25D
what are 3 theraputics to increase bone denstiy
- PTH
- biphosphonates
- SERM
what does biphosphonate do
effective inhibition of bone resorbtion by inactivating clasts
what is structure of biphosphonate
2 phosphonate groups with various side chains
