Exam #1: Minerals I Flashcards
What is a mineral?
Elements found on the periodic table that are not broken down by the body
What is the difference between a macromineral and a micromineral?
Requirements
Macro= >100 mg/day
Micro=
List the macrominerals.
Ca++ Phosphorus K+ Sulfur Na+ Cl- Mg++
What is unique about Ca++ & phosphorus?
Higher requirement for pediatric population b/c of role in bone growth
What are the major functions of the macrominerals?
- Cellular activity
- Osmotic properties of body fluids
- Bones & teeth
- Cofactors
What is the DRI for water in the US for males and females?
Male= 3.7 L/day Female= 2.7 L/day
How much of a decrease in body water can be life threatening?
10%
Describe the distribution of water in the body compartments.
60%= intracellular 40%= extracellular
What is the relationship between water and muscle/ fat?
- Increased w/ lean muscle mass
- Decreased w/ fat
What is the major cation of the ECF?
Na+
What are the major functions of Na+?
- Regulation of fluid movement
- Active reabsorption results in passive reabsorption of many other substances
What is the major cation of the ICF?
K+
Where is Cl- found in the body?
Primary ECF anion (-)
What is the TUL for Na+? How does this compare to the typical intake?
2.3g
*****Typically we see a daily minimum of 2.3g
How does K+ intake compare to Na+?
K+ is much lower b/c of a lack of fruits and vegetables in the diet
What is the effect of low K+ intake in our diet?
- Increased BP
- Increased salt sensitivity
- Increased bone turnover
- Increased risk of kidney stones
How does a high Na+ & low K+ diet lead to HTN?
- Hyperactive SNS
- Subtle renal injury
- Decreased Na+ excretion
- Increased BP
What are the major function of Ca++ in the body?
- Bone health
- Muscle contraction
- Clotting
- Nerve conduction
- Enzyme regulation
- Membrane permeability
How do Ca++ requirements change throughout life?
- High as children
- Relatively low in middle age
- Increased in elderly population
How does Na+ intake alter Ca++ balance?
Increases excretion of Ca++
How does protein intake alter Ca++ balance?
Increases excretion of Ca++
**Protein makes blood more acidic, excrete Ca++ to balance
How does caffeine intake alter Ca++ balance?
Increases excretion
How does alcohol intake alter Ca++ balance?
Decreases absorption
How do fruits and vegetables alter Ca++ balance?
Reduce excretion
What is the role of Ca++ supplementation in preventing hip fracture?
Supplementation with 750mg has been shown to be beneficial/ prevented fracture
What are the major function of phosphorus?
- Major anion in cells
- ATP production
- Acid-base balance
What two hormones stimulate phosphorus absorption?
PTH
Vitamin D
What is the effect of phytic acid (grains) on phosphorus?
Decreased bioavaliability
What macrominerals can impair phosphorus absorption?
Mg++
Aluminum
Ca++
What populations are at risk for phosphorus deficiency?
- Premature infants
- Ca++ supplements/ antacids
- Malabsorptive disorders
- Alcoholism
- Uncontrolled DM
- Burns
- Refeeding syndrome
What are the major functions of Mg++?
1) Bone mineralization
2) Cell membrane?
3) Cofactor for many enzymes
What is the effect of phytate and fiber on Mg++?
Impaired absorption
What do unabsorbed fatty acids to do Mg++?
Bind to form soaps that are excreted in feces
What is the effect of Vitamin D & lactose on Mg++?
Increased absorption
