Chapter 14: Major Minerals Flashcards
Mineral Definition
A naturally occurring element that is:
- Inorganic
- Needed in small amounts (micronutrient)
- Essential
Major minerals (amt)
Required in amounts of >100 mg/d
Needed in greater amounts in the body and stored in larger amounts vs trace minerals
Trace minerals (amount)
Required in amounts that are <100 mg/d
Major minerals
Calcium
Chloride
Magnesium
Phosphorus
Potassium
Sodium
Trace minerals
Fluoride
Iodine
Iron
Selenium
Zinc
Digestion of minerals
They do not require digestion because they are in “free” form
Where are minerals absorbed
Small intestine and Large intestine
- Minerals are directly absorbed and enter the blood stream
- There are factors that can affect the amount that is absorbed
Factors that affect mineral absorption
Physiological need for the mineral
- Periods of growth
- Body has adequate stores
Bioavailability
- The amount of a nutrient that is absorbed and made available
- Factors that influence bioavailability (interactions with other vitamins and minerals or gastric acidity)
- Binding by plant chemicals
Where is phytic acid found and what does it bind to (influencing bioavailability)
Found in wheat
Binds to zinc and iron
Where is oxalic acid found and where does it bind to (influencing bioavailability)
Found in leafy, green plants
Binds to calcium
Where are polyphenols found and where do they bind to
Found in tea, dark chocolate, wine
Bind to calcium and iron
How are minerals transported
Once in the bloodstream, they are transported in free form or bound to proteins
Storage of minerals
Amount that is store varies widely
EX:
- Large amounts of calcium and phosphorus are stored in bones
- small amounts of iron stored in liver and bone marrow
Excretion of minerals
Most are excreted via urine
Functions of sodium
Transmission of nerve impulses
Muscle contraction
Absorption of nutrients: glucose and amino acids
Major sources of sodium in the American diet
- Salt! It’s 40% Na and 60% Cl
- Processed foods (processing increases sodium content)
What is the AI for sodium
1,500 mg/d
What is the upper limit for sodium
2,300 mg/d
What % of adults exceed the AI
97%
Consequences of excess sodium
Hypertension -> heart disease and stroke
Increased urinary calcium excretion -> kidney stones
(Sodium naturally increases blood pressure)
Potassium functions
Nerve transmission and muscle contraction
Regulate urinary calcium excretion
Regulate blood pressure
AI for potassium
Males: 3,400 mg/d
Females: 2,600 mg/d
Good sources of potassium
Fruits and vegetables
Consequences of too little potassium intake
Hypertension -> heart disease and stroke
May affect bone health
Functions of Chloride
Component of HCl
Immune function
Maintenance of acid-base balance
Food sources of chloride
Table salt
Processed foods
Seaweed
Olives
Rye
Some fruits and vegetables
Systolic blood pressure
Maximum blood pressure within an artery that occurs when the ventricles contract
Diastolic blood pressure
Pressure in an artery that occurs when the ventricles relax between contractions
Hypertension
Condition characterized by persistently elevated blood pressure
Normal blood pressure
Systolic: less than 120
Diastolic: less than 80
Elevated Blood pressure
Systolic: 120-129
Diastolic: less than 80
High blood pressure (hypertension) stage 1
Systolic: 130-139
Diastolic: 80-89
High blood pressure (hypertension) stage 2
Systolic: 140 or higher
Diastolic: 90 or higher
Hypertensive crisis
Systolic: higher than 180
Diastolic: higher than 120
Treatment for hypertension
- follow dietary modifications
- manage stress
- take prescription medications
- incorporate physical activity
The dietary approaches to stop hypertension (DASH) diet is:
- low in sodium, total fat, saturated fat, cholesterol
- high in fruits, vegetables and low-fat dairy products
What is the best lifestyle modification to lower blood pressure
Weight reduction
Functions of calcium
Develops and maintains bone
(Vitamin D impacts calcium absorption)
Nerve impulse transmission
Muscle contraction and relaxation
What are the two types of bone
Compact (75%) and Spongy/trabecular (25%)
Bone building cells
Osteoblasts: produce collagen, add minerals
Osteocytes: Take up and release bone minerals
Bone-resorbing cells
Osteoclasts: release acid and enzymes to dissolve bone (when there is not enough calcium)
Where is calcium located
99% of it is in the bones
1% is blood calcium
RDA of calcium
Males and females: 1,000 mg/d
Factors that decrease bioavailability of calcium
Dietary phosphorus
Polyphenols
Bind to calcium in foods (phytic and oxalic acid)
Factors that increase calcium bioavailability
Each calcium rich foods with other foods, especially those that contain lactose, other sugars and protein
Where is calcium absorbed and what is the absorption efficiency rate
It is absorbed from small and large intestines
- Usually 25-30% absorption efficiency
Factors that enhance calcium absorption
Vitamin D (calcitriol)
Stomach acid
Lactose (only in infants)
Factors that decrease calcium absorption
Vitamin D deficiency
Reduced stomach acid secretion
Phytic and oxalic acid intake
High fiber intake
High phosphorus intake
Chronic diarrhea
Fat malabsorption
What hormones do the thyroid and parathyroid glands secrete to regulate blood calcium levels
Thyroid - calcitonin (when calcium is high)
Parathyroid - releases Parathyroid hormone
What is parathyroid hormone
Secreted by parathyroid glands when blood calcium levels are low
What can hyperparathyroidism cause
It can cause persistently elevated blood calcium
What is the UL of calcium
2000 to 2500 mg/day
What is hypercalcemia and its symptoms
High blood calcium
Symptoms: kidney stones, bone pain, muscle weakness and fatigue, hypertension, can lead to kidney failure and decreased absorption of other minerals
Phosphorus function
Major component of bones and teeth
Regulates acid-base balance
Energy production and storage (component of ATP and creatine phosphate)
Component of
- DNA and RNA
- Phospolipids in cell membranes
Enzyme and cellular message systems
Where is phosphorus found in the body
85% found in bone
Good food sources of phosphorus
- Meat / Fish / Poultry
- Dairy
- Legumes
Magnesium function
- Bone structure and mineralization via calcium metabolism
- Cofactor for >300 enzymes that use ATP (energy metabolism, muscle contraction…)
- DNA/RNA synthesis
- Nerve transmission
- Regulates blood pressure (vasodilation/lowers BP and heart rhythm)
Good food sources of magnesium
- Legumes
- Nuts/seeds
- brown rice, whole wheat bread
- Seafood
- Dark green leafy vegetables
What is hypermagnesemia
High blood magnesium
What causes magnesium toxicity
Most likely from ingesting excessive amounts from laxatives, antacids or dietary supplements (NOT BC OF FOOD)
What is osteoporosis
A chronic disease characterized by bones with low mass and reduced structure
What is osteopenia
A condition in which a person has weak bones that are susceptible to fracture
What is peak bone mass and what age does is occur
Present when bones have their maximum strength (age 20-30)
Nonmodifiable risk factors of osteoporosis
Female
Growing older
Having white or Asian ancestry
Having a family history of osteoporosis
Having a small, thin boned body frame
Too little estrogen in the body
Modifiable risk factors of osteoporosis
Having anorexia
Having low estrogen (women) or low testosterone (men)
Following diets that have inadequate amts of calcium and vitamin D
Using medications such as steroids or some types of anticonvulsants
Low physical activity
Smoking cigarettes
Consuming excessive alcohol, coffee or other caffeinated beverages
Additional health benefits of calcium
Reduces risk for colon cancer, kidney stones, and blood pressure
What is the best calcium supplement
Calcium carbonate - antacids
How should supplements be taken to increase absorption
In doses of 500 mg or less just before or after meals
Adverse effects that can be caused by taking calcium supplements
GI symptoms
Calcification of coronary arteries, that may increase risk for CHD
Potential interactions with other minerals
Contaminated supplements may contain lead
