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Flashcards in 32 - Minerals Deck (66)
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Describe minerals

- Found on the periodic table
- Not broken down by digestion nor destroyed by heat or light
- Macrominerals: required at amounts >100mg/day
- Trace minerals: required at amounts


How much of minerals do we have of minerals in our bodies?

- More than a pound of calcium and phosphorus
- Also, potassium, sulfur, sodium, chloride, magnesium, etc.


Describe water balance

- Metabolic
- Foods
- Beverages

- Feces
- Lungs
- Skin
- Urine


What is the water intake recommendation?

Male = 3.7 L
Female 2.7 L


Describe water in the body

A decrease of 10% in body water can be life threatening


Describe the functions of water in the body

- Solvent
- Regulate body temperature
- Lubricate joints, digestive tract, eyes
- Transport


Describe the distribution of water in the body

- Body water weight associated with lean body mass
- 60% of body water – intracellular fluid
- 40% of body water – extracellular fluid (32% interstitial, 8% intravascular)


Describe electrolytes in the body

Electrolytes - anions and cations (Na+, K+, Cl-)
- Maintain electrical neutrality
- Help maintain pH
- Deficiencies rarely occur


Describe sodium in the body

- Major cation in extracellular fluid
- Freely filtered by glomerulus
- Regulates fluid movement
- Active reabsorption results in passive reabsorption of chloride, bicarbonate ions, and water (maintain neutrality of extracellular fluid & osmotic pressure


Describe potassium in the body

- Chief cation of intracellular fluid
- Cells: high potassium, low sodium
- Extracellular fluids: high sodium, low potassium
- Requires energy to maintain balance


Describe chloride in the body

- Primary extracellular anion
- Primarily absorbed as NaCl
- Reabsorbed by kidney (follows Na)


Describe the recommendations for sodium and potassium intake

- 1.5 g is adequate
- 2.3-4.5 is typical

Sodium chloride
- 3.8 g is adequate
- 5.8-11.3 g is typical

- 4.7 g is adequate
- 2.1-3.2 g is typical


Describe the dietary guidelines for sodium

The Dietary Guidelines for Americans, 2010 recommend that Americans aged 2 and up reduce sodium intake to less than 2,300 milligrams (mg) per day.

True dietary deficiencies of electrolytes typically not seen; low serum levels more likely to be due to a metabolic problem (e.g. refeeding syndrome leads to hypokalemia)


Describe the potassium to sodium ratio and its effects

- Pre-industrialization diet comprised of meat, vegetables, fruit. Today, largely comprised of processed/packaged foods
- Ratio of K/Na has shifted from 10:1 to 0.4:1


What is the effect of low potassium?

- Increased blood pressure
- Increased salt sensitivity
- Increased bone turnover
- Increased risk of kidney stones


Describe the acquisition of salt sensitive hypertension

- Normal kidneys are okay at handling sodium overlaod
- If any renal injury has occurred, it cannot excrete the sodium it needs to
- High sodium diet then leads to hypertension
- The BP will remain high even after the acute kidney injury has healed
- If they then have a drastic drop in salt intake, they will then experience hypotension because they have become "salt sensitive" in terms of BP control
- Example: get sick and don't eat for 2 days... Hypotension due to low salt will result


What is a salt substitute?

Potassium (sodium free) flavoring

Not good for patients with restricted potassium intake


Describe calcium in the body

Serum concentrations tightly regulated both intracellularly & extracellularly

3 hormones
- Calcitriol
- Calcitonin


What are the funcitons of calcium in the body?

- Bone health
- Muscle contraction
- Blood clotting (with vitamin K)
- Nerve conduction
- Enzyme regulation
- Membrane permeability


Describe bone health in relation to calcium

Approximately 99% of total body calcium is found in bone & teeth

Bone formation
- Calcium, protein, magnesium, phosphorus, vitamin D, potassium, and fluoride
- Other vitamins and minerals needed for metabolic processes related to bone formation
- Manganese, copper, boron, iron, zinc, vitamin A, vitamin K, vitamin C, and the B vitamins


Describe the requirement for calcium over a life span

- Requirement during adolescence is 1300 mg
- Bone mass peaks in 30s then begins to decline
- Declines more in women than in men (hormone changes)


Describe how the diet plays a role in calcium absorption

- Vitamin D has a large role (non-diet)
- Caffeine, alcohol and others can decrease absorption


Can calcium decrease hip fracture risk?

Yes - 300 mg/day calcium supplement


Describe phosphorous in the body

- Approximately 85% of body’s phosphorus is in skeleton, 14% in soft tissue, 1% in blood & fluids


What are the functions of phosphorous?

- Major anion within cells
- Contributes to ATP production
- Acid-base balance


Describe the absorption of phosphorous

- PTH & Vitamin D stimulate absorption
- Phytic acid (grains) decreases bioavailability
- Magnesium, aluminum, calcium impair absorption


Describe the excretion of phosphorous

- Balance maintained by renal excretion
- 67-90% excreted in urine; remaining in feces
- Dietary intake and absorption linear to excretion


Describe phosphorous deficiency

- Deficiency is rare
- Phos is present in most foods
- Body adapts to fluctuations by changes in excretion

Who is at risk....
- Premature infants
- Those receiving large amounts of calcium supplements or aluminum antacids (fight for same receptors)
- Malabsorptive disorders (Crohn’s)
- Alcoholism
- Uncontrolled diabetes
- Burns
- Refeeding syndrome


Describe magnesium in the body

Approximately 55-60% in bone, 20-25% in muscles; remaining in extracellular fluids


What are the funcitons of magnesium?

- Bone mineralization (forms the crystal lattice along with phosphorus and calcium)
- Cell membranes – bound to phospholipids
- Enzymes (>300 enzymes require magnesium to function): glycolysis, Krebs cycle, etc.