calcium

Question 1

how many g of calcium is in the bones, rest of body and in total

Answer 1

bones - 1185g
rest- 15g - 7 in teeth, 7 outside, 1 inside cells
total - 1200g

Question 2

how many g of phosphorus is in bones, rest of body and total in body

Answer 2

bones - 600g
rest - 100g
total - 700g

Question 3

how many g of magnesium is in bones, rest of body and total in body

Answer 3

bones - 15g
rest - 12g
total - 27g

Question 4

what form does calcium occur in, in the environment and body

Answer 4

occurs as calcium carbonate in the environment ; occurs as calcium phosphate in the body.

Question 5

what does regulation mean in terms of calcium

Answer 5

that plasma Ca cannot be used as a measure of calcium status.

Question 6

calcium is required for the homeostatic control of what

Answer 6

of the absorption, excretion, secretion, and deposition – parathyroid hormone (PTH); 1,25 (OH)2 D3; calcitonin

Question 7

To ascertain nutritional status requires what

Answer 7

complex measurements of bone mineral content and/or density

Question 8

explain relationship between calcium intake and absorption

Answer 8

The efficiency of absorption of Ca is higher at low intakes

At low intakes, more Ca is lost in the faeces than is taken in the food; calcium is secreted in the intestinal juices.

Question 9

on a typical diet the net proportion of calcium absorbed is

Answer 9

25-30% of the intake.

Question 10

what are the 2 routes that calcium can be absorbed by in the intestine

Answer 10

Transcellular – active, calbindin-dependent, vit D regulated

Paracellular – passive, concentration-dependent.

Question 11

what can calcium absorption be improved by

Answer 11

– lactose
– amino acids
– casein
– low Ca intake
– ingestion with a meal
– pregnancy
– lactation

Question 12

what can calcium absorption be reduced by

Answer 12

– long chain fatty acids but only with fat malabsorption
– phosphate but only in excess
– phytate from bran
– oxalate
– vit D deficiency
– menopause, old age
– intestinal disease

Question 13

in bones and teeth the calcium and phosphorus form crystals of what with what kind of structure

Answer 13

crystals of hydroxyapatite, Ca10(PO4)6(OH)2, form the rigid structure.

Question 14

from 15mg/kg/d of calcium in food how much is lost as waste

Answer 14

11mg/kg/d as feaces
4mg/kg/d as urine

Question 15

explain the process of calcium secretion

Answer 15

15mg/kg/d is in taken of calcium in food, this goes to intestine where 7mg/kg/d is absorbed to a calcium pool. 4mg/kg/d is used in bones which is turnover (so same come out of bones). 3mg/kg/d of the calcium in the calcium pool goes into digestive juices back into the intestine. the calcium pool then moves to the kidney where 4mg/kg/d of calcium is lost in urine
and 11mg/kg/d of calcium is lost from the intestine through faeces

Question 16

explain the relationship between growth rate and calcium

Answer 16

Higher the rate of growth the higher need of calcium
so is why very young children/ babys need lost calcium

Question 17

explain bone mineral content and calcium between men and women

Answer 17

Bone mineral density peaks between 25-30years. From this point, it’s a progressive decline from that peak

Males are more muscular and are bigger so bigger bones and so their bone mineral density peaks higher than the peak for females.
Males calc doesn’t decline at same rate as women
Osteoporosis is more common in elderly females than males. Stopping them from possibly being able to walk without bones breaking.

Physical activity and diet prevent this rapid bone mineralisation decline

Question 18

in Britain how much calcium on average is lost from urine and skin

Answer 18

daily urinary losses of 150 mg are found
with 10 mg/d lost from the skin.

Question 19

Assuming that 30% of calcium is absorbed from mixed British diets, it is suggested that about how many mg/d is needed on average, with no allowance for difference in sex.

Answer 19

525 mg/d

Question 20

what are the RNI in UK for adults, male and females between ages (11-18) and during lactation

Answer 20

Adult RNI: 700 mg/d

higher levels are set for 11-18 year olds:
Male RNI: 1000 mg/d
Female RNI: 800 mg/d

(Lactation: +550 mg/d)

Question 21

can we get calcium from sources other than dairy and calcium

Answer 21

yes
but where low intake of milk calcium theres also a low intake of total calcium

Question 22

does skimming milk take away calcium content

Answer 22

no

Question 23

describe calcium content in soft and hard cheese

Answer 23

Softer the cheese the less calcium , so harder cheeses have more calcium. But is variable

Question 24

name some high calcium sources that are dairy products

Answer 24

cows milk,
human milk
skimmed milk
cheddar cheese(made with rennet)
yoghurt
butter
cottage cheese

Question 25

name some high calcium sources that are non dairy

Answer 25

baking powder
self raising flour
white flour
wholemeal flour
meat, offal
fish
hard water- found more in south england

Hard water can form a scum on the top , due to its high levels of calcium
Amount of calc in water varies massively and depends on its location

Question 26

the USA has tolerable upper intake of calcium why

Answer 26

Because of high Ca intakes from supplements can lead to

nephrolithiasis (kidney stones)
hypercalcaemia
renal insufficiency
reduced absorption of Fe, Zn, Mg, & P

Question 27

what is the safe upper intake value for calcium

Answer 27

2500 mg/d