Week 11 - Major Minerals

Bioavailability

The degree to which a mineral can be absorbed (>40%)

• High bioavailability >40% absorbed

• low bioavaialbility <10%

How many essential minerals are there

16 essential minerals

Macro: 100 mg/day

Micro —> I, Fe, Se, Zn

Sodium role

1. Principle cation of extracellular fluid & main regulator of the volume

2. maintain acid-base balance

3. essential to nerve impulse transmissions

4. key for healthy muscle contractions

Filtered by the kidneys after filtering from blood the same amount is returned

Sodium sources

• milk, meat and shellfish

• processed foods

Deficiency of sodium

may drop from vomiting, diarrohea or heavy sweating

• Low Na conc. —> hyponatremia

• High Na conc. —> High BP and Edema

Chloride

Reacts with major minerals Na/H to form Cl-

• Major anion of extracellular fluids

• moves passively along membrane and associates with K (ICF)

• Stomach Cl- maintains acidity

Deficiency and toxicity for Cl

Deficiency is rare, cause vomiting, heavy sweating

Toxicity from dehydration

Potassium roles

1. maintain fluid balance

2. nerves to respond to stimulation and muscle contraction

3. move nutrients into cell and waste products out

4. balance effects of Na on blood pressure

Sources of potassium

as long as the cells are intacct

• fruits, vegetables, fresh foods

Deficiency and toxicity of potassium

Deficiency

• increase blood pressure

• kidney stones

• irregular heartbeat

• bone turnover

• muscle weakness

• glucose intolerance

Toxicity

• vomiting and muscle weakness

Calcium roles

1. Grow healthy skeleton

2. minimises the loss of bone

3. muscle contraction

4. blood clotting

What mineral is the most abundant in the body?

Calcium

Hormones to regulate calcium in blood

1. Parathyroid hormone

• Parathormone breaks down bone tissue to release Ca2+

2. Calcitonin

• Decrease Ca2+ in blood by slowing breakdown of bone

Deficiency of calcium

>50 years old bone loss is accelerated

1. Osteopenia (weak bones)

• less serious than osteoperosis

2. Osteoperosis

• break under daily stress

Phosphorous

Second most abundant mineral

• found in bones and teeth

• combined with Ca2+ in the hydroxypatite crystals that form them

• part of DNA and RNA

• many enzymes and b vitamins only become active when a phosphate group is attached

phospholipids are used by lipoprotein vehicles

• transportation of lipid in blood

• major structure of cell membrane

Sources of phosphorous

foods rich in protein

processed foods (soft drinks with phosphate based additives)

Phosphate toxicity

Linked to kidney failure

How does phosphorus exist in milk

phosphoproteins

Magnesium

essential for synthesis of carbohydrates, lipids, nucleic acid and protein

• work with Ca2+ to regulate muscle contraction and blood clotting

Sources of magnesium

• Green leafy vegetable

• Legumes

• Nuts

• Whole grains

Foods high in FIBRE

Deficiency of magnesium

increased inflammation —> heart disease, stroke, cancer

hypertension

toxicity is rare

Sulphate

Oxidised form of sulfur

• stabilised the shape of proteins by forming disulfide bridges

• exist in food and H2O

Deficiency of sulfate comes from the lack of?

Protein

What part of the body has the highest sulfur content?

Skin

Nails

Hair

all are RIGID proteins