Chapter 9
Friday, November 1, 2019
10:16
Minerals
→ Major
○ >100 mg/day
○ Calcium
○ Phosphorus
○ Sulfur
○ Potassium
○ Sodium
○ Chloride
○ Magnesium
→ Trace
○ <100 mg/day
○ Iron
○ Zinc
○ Copper
○ Iodine
○ Selenium
○ Molybdenum
○ Fluoride
○ Manganese
○ Chromium
→ = 4% of body weight
Regulatory & Structural Function
→ Part of hormones/enzyme
→ Transmit impulses
→ Maintain fluid balance
→ Support immune system
→ Cofactors in chemical reactions
→ Partner with other minerals
→ Bone formation/maintenance (calcium, magnesium, phosphorus)
→
→
→
→
→
Maintain fluid balance
Support immune system
Cofactors in chemical reactions
Partner with other minerals
Bone formation/maintenance (calcium, magnesium, phosphorus)
Absorption & Bioavailability
→ Affected by nutrition
○ Deficiency
○ Increased need
→ Competition between minerals
→ Presence of binders
○ Phytates
○ Oxalates
○ Polyphenols
○ Others
Calcium
→ Most abundant in the body
→ 99% in bone and teeth (structural, reservoir of calcium)
→ 1% in cells and fluids
○ Coagulation
○ Hormone secretion
○ Muscle contraction
○ Nerve transmission
→ Sources
○ RDA = 1000 mg/day (adults 19-50 years old)
○ UL = 2500 mg
○ Plants (reflect mineral in soil)
○ i.e. red soil in Hawaii - high in iron
○ Whole, unprocessed food
○ Animal products (dairy)
○ Tap water
○ Hard - calcium, magnesium
○ Soft - sodium
○ Leafy greens
○ Legumes
○ Supplements
**High intake -- constipation, iron absorption interference, hypercalcemia
○ Soft - sodium
○ Leafy greens
○ Legumes
○ Supplements
**High intake -- constipation, iron absorption interference, hypercalcemia
→ Blood levels managed by calcium homeostasis
→ Levels fall :
○ Parathyroid hormone released (from PT gland)
○ PTH stimulates active vitamin D production
a. Increases calcium absorption in intestine
b. Releases calcium from bone
c. Decreases calcium excretion from the kidneys
→ Bone is constantly broken down and rebuilt for blood calcium maintenance and
growth
○ osteoCLASTS cut away bone
○ osteoBLASTS build up bone
→ Higher peak bone density decreases osteoporosis risk
→ Bone Mass Phases
○ Male Peak - around 20 to 40 years; then gradual slope decrease with age
○ Female Peak - around 25 to 40 years; more dramatic loss around 50 years
due to menopause; then gradual slope decrease with age
Magnesium
→ 50 - 60% in bones
→ Functions
○ Transport ions for :
§ Muscle contraction
§ Impulse conduction
§ Maintaining heart rhythm
○ Extract energy from carbs, proteins, fats
○ Protein production
○ Vitamin D activation
○ Bone health
→ 60% of Americans do NOT meet recommendations
→ Symptoms of deficiency : rare, kidneys excrete less, body absorbs more
→ Increase risk of :
○ Osteoporosis
○ Atherosclerosis
○ Cancer
○ Diabetes
→ Increase risk of :
○ Osteoporosis
○ Atherosclerosis
○ Cancer
○ Diabetes
○ Hypertension
→ Sources
○ Present in small quantities in all groups
→ Excess intake from food = rare
→ Toxicity from supplements, laxatives, antacids = diarrhea, nausea, cramping