Lecture 12 Minerals

Question 1

Minerals

Answer 1

• inorganic elements needed by the body
• build tissues
• form body structures (bones)
• regulate body fluids
• assist in body functions (metabolism)

Question 2

Vitamins vs. Minerals

Answer 2

Vitamins: organic, sensitive to heat, air, acid, light

Minerals: inorganic, not sensitive

Question 3

Minerals as cofactors

Answer 3

• cofactors are inorganic
• required for catalysts
• not to be confused with coenzymes (vitamins; organic)

Question 4

Calcium

Answer 4

Functions:

• bone structure (99% is stored in teeth/bones)
• muscle contraction
• nerve transmission

Sources:

• milk
• cheese
• fish (sardines)
• legumes
• broccoli
• spinach

Regulation of blood calcium levels:

• calcitonin –> lowers calcium levels
• parathyroid hormone –> increases calcium levels

Calcium Absorption:

• Active diffusion
• Passive diffusion
  
  • (25-30% absorption)
  • decreases with age

Calcium Bone Health
- peak bone mass is developed in the first three decades of life

DRI: 19-50yr: 1000 mg/day
51+yr: 1200 mg/day
UL: 2500 mg/day

Deficiency:

• stunted growth
• osteoporosis

Toxicity:

• kidney stone
• tissue calcification

Question 5

Osteoporosis

Answer 5

Risk:

• 1 in 3 women
• 1 in 5 men

Risk factors:

• gender
• age
• race
• family history
• body size
• lifestyle

Question 6

Calcium and exercise benefits

Answer 6

research shows that consuming additional calcium past the RDI does not improve results

Question 7

Sodium/Potassium

Answer 7

Functions:

• major part of fluid and electrolyte balance
• essential to muscle contraction and nerve transmission

Sodium DRI: 
- 19-50yrs: 1500 mg/day
- 51-70yrs: 1300 mg/day
- 71+yrs: 1200mg/day
UL:
- 2300 mg/day

Potassium:
AI: adults: 4700 mg/day
UL: N/A

Electrolyte:

• Sodium:
  
  • deficiency
    
    • cognitive impairment
    • muscular contraction problems
  • toxicity
    
    • chronic intake can result in increased BP, CVD
• potassium
  
  • Deficiency
    
    • muscle weakness
    • paralysis
    • confusion
  • Toxicity:
    
    • muscle weakness
    • vomiting
    • lethal if injected into the vein

Question 8

Water Balance

Answer 8

• 60-70% are intracellular
• 20-25% are interstitial
• 5-10% are plasma

Dehydration and Overhydration:

• hyponatremia (sodium levels drop below 135 umol/L)
• ingest 10-20 L in < 5 hours
• healthy kidneys excrete 800ml to 1L per hour

Question 9

Iron

Answer 9

Functions:

• hemoglobin
• myoglobin
• energy metabolism

Deficiency:

• anemia
• impaired mental and physical work performance

Groups at risk:

• women of childbearing age
• pregnant women
• infants >6 months of age (toddlers)

Toxicity:

• GI distress
• fatigue
• joint pain
• organ damage

Question 10

Absorbing Iron

Answer 10

1) heme (meat, fish, poultry; MFP factor)
- 10-35% absorbed
2) nonheme (plants)
- 2-20% absorbed
- vegetarian 1.8X the normal requirement

Dietary factors that increase iron absorption

• Vitamin C
• MFP factor

Factors that hinder iron absorption

• tea
• coffee
• calcium
• fibre