List 4 functions of calcium -
- Development of bones and teeth
- blood clotting
- contraction and relaxation of muscles
- conduction  of messages along nervers

What other nutrients are necessary  for the effective use of calcium -
- milk
- cheese
- edible bones of tinned fish
- 'Hard' water
- flour to which calcium compounds have been added

Name 3 substances which hinder the absorbtion of calcium -
- Oxalic acid (in spinach, green bananas, rhubarb)
- Phytic acid (in cerals, bran, nuts and pulses)
- Large amounts of fatin the intestine

List the recommended daily allowences of calcium for the following groups:
Children - 500-1100mg
Teenagers - 500-1400mg
Adults - 800mg
Pregnant and lactating women - 1500-2000mg

List the richest food sources -
- milk
- cheese
- edible bones of tinned fish
- 'Hard' water
- flour to which calcium compounds have been added

Why do teenagers need more calcium daily that adults -
Teenagers need more calcium than adults because their bones are still growing and developing so they need more calcium than an adult.