Calcium

• Oat milk


  UPF
• RDI for 31 - 50 year olds

  1000mg/day
• Are women in NZ consuming enough calcium

  No
• Calcium paradox


  There is not a strong correlation between bone and bone mass and calcium
• How much calcium is absorbed from the diet 


  25 - 30%
• Who’s bodies will absorb more calcium from their diet?

  Pregnant women
• What works together with Calcium 


  Vitamin D
• Not enough vitamin D in the diet leads to …


  a reduced amount of calcium which the body can absorb
• Bioavailability 


  The proportion of a nutrient that is absorbed, utilized and thus available to the body
• 2 Ways calcium gets into the diet

  1. active transport - body regulates how much intake it needs, has a limited capacity
  2. passive diffusion - high concentration to low concentration, bioavailability
• Promotors and inhibitors 


  Promotors - proteins/Amino acids, lactose, acidic gut

  Inhibitors - oxalate, other minerals with +2 charge, phytate
• Excretion

  • most Is lost through the urine
  • some is lost through faeces and sweat
• Factors which affect calcium loss

  • protein, sodium, caffeine can all increase calcium excretion
  • phosphorus, bicarbonate, citrate lower
• Bones 


  *Don’t worry about the hormones

  
• In blood plasma ..

  Ca is biologically active so blood concentration is tightly controlled
• Functions of calcium 


  1% - intracellular messenger

  99% - bone
• Intracellular messenger - very important

  • nerve transmission
  • muscle contraction
  • hormone secretion
  • cell membrane
  • others ..
• Bone (99% of bodies calcium)

  • structural role - skeleton
  • physiological role - reservoir of essential minerals
• Teeth


  Protein matrix + Hydroxyapatite crystal

  Ca10(OH)2(PO4)6
• Calcium for bones


  Lack of intake = decrease in bone mass + bones become more brittle

  
• Calcium deficiency

  • children have a decrease in growth and bone mass
  • adults decrease in bone mass
  • can’t be identified from outside the body
• a heath risk due to deficiency 


  Osteoporosis
• what should you always do before using a carton of dairy replacement milk

  shake the carton as the calcium which has been fortified settles at the bottom
• DASH studies (1 and 2)

  1. Demonstrated that dietary changes could have a positive impact on BP - could have similar effects to medication, were short term, BP is not the most important outcome
  2. long term studies have demonstrated reduced dietary sodium reduces risk of stroke - consensus that sodium intake should reduced
• 2008/2009 ANS average consumption of calcium

  919 mg/day - male

  745 mg/day - female
• EAR for 31 - 50 year olds

  800 mg/day
• Main sources in diet

  Milk, bread, non-alcoholic drinks, cheese