NHM 101 Lecture Notes - Lecture 15: Phytic Acid, Bone Density, Osteopenia
2 May 2018
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Ch 12 & 13 - Minerals
Major Minerals- needed in large amounts
Trace Minerals- needed in small amounts
Inorganic Elements- contain NO carbon
● CANNOT be changed by heat, air,
acid, or mixing
Variable Bioavailability- binders in food
can combine chemically with minerals and
prevent their absorption
●
Phytates
- in legumes and grains
●
Oxalates
- in spinach and rhubarb
Minerals can be lost when leached into
water.
Calcium
Most abundant mineral in the body.
● Bone and teeth
● Small amount in bodily fluids
Bones are a bank of Ca+ for the blood and are
continuously gaining/losing minerals.
● Blood calcium should almost always be
normal.
Absorption:
● Adults absorb ~30% ingested
● Infants, teens, expecting mothers absorb
more
● Vitamin D supports absorption and
deficiency impairs it
● Fiber, phytates, and oxalates interfere
RDA
Adults/Men 51-70: 1000 mg/day
Men 70+: 1200 mg/day
Women 50+: 1200 mg/day
Adolescents: 1300 mg/day
UL: 2500 mg/day
Actual calcium intakes are too low.
Food Sources:
● Milk products
● Green vegetables
● Tofu
● Almonds
Deficiency- limits peak bone mass & weakens
bones
● Peak bone mass is reached by 30 yr
● Bone loss typically occurs between 30-40
● Excess bone loss can cause fractures due to
osteopenia or osteoporosis (considered a
silent killer)
● Important to measure bone density
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Phosphorus
Assists in energy metabolism
● ATP
Provides structure to phospholipids
● Lipid transport
● Component of cell membranes
Found in bones, teeth, and ALL body cells
RDA for adults: 700 mg/day
UL: 4000 mg/day
Food Sources:
Animal foods (meat, fish, eggs, milk)
Deficiency is UNLIKELY.
Potassium
● Main intracellular cation
● Maintains fluid and electrolyte balance
Hypertension & the DASH Diet
● Low potassium + high sodium = BAD
● High potassium + low sodium = GOOD
AI for adults: 4700 mg/day
Food Sources:
Whole foods
● Milk, meats, grains, legumes
● FRUITS & VEGETABLES
Deficiency
● High blood pressure
● Salt sensitivity
● Kidney stones
● High burn turnover
Toxicity
● Overconsumption of potassium
supplements
● Kidneys accelerate excretion
Sulfur
Sodium
● Main extracellular electrolyte
● Maintains fluid balance
● Maintains acid-base balance
● Involved in nerve transmission and muscle
contractions
Metabolism: kidneys filter sodium out of the blood
- Amount excreted should equal the amount
ingested
- When blood Na+ rises, thirst signals
encourage drinking
- Kidneys then excrete both excess water
and sodium
AI for 19-50: 1500 mg/day
UL for adults: 2300 mg/day
Dietary Guidelines 2020: <1500 mg/day for
African-Americans, elderly, those w/ hypertension
Actual average intake is 3400 mg/day
Food Sources:
● Processed foods (75%)
● Table salt (15%)
● Occurs naturally in some foods (10%)
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Cannot be changed by heat, air, acid, or mixing. Variable bioavailability- binders in food can combine chemically with minerals and prevent their absorption. Minerals can be lost when leached into water. Bones are a bank of ca+ for the blood and are continuously gaining/losing minerals. Blood calcium should almost always be normal. Vitamin d supports absorption and deficiency impairs it. Deficiency- limits peak bone mass & weakens bones. Peak bone mass is reached by 30 yr. Excess bone loss can cause fractures due to osteopenia or osteoporosis (considered a silent killer) Found in bones, teeth, and all body cells. Low potassium + high sodium = bad. High potassium + low sodium = good. Metabolism: kidneys filter sodium out of the blood. Amount excreted should equal the amount ingested. When blood na+ rises, thirst signals encourage drinking. Kidneys then excrete both excess water and sodium. Blood na may drop with vomiting, diarrhea, or heavy sweating.
