Human Nutrition Flashcards
Vitamins
what are Macro Minerals
Calcium, Magnesium, Phosphorus, Chloride, Potassium, Sodium and sulphur
what are trace minerals
Chromium, Cobalt, Copper, Fluorine, Iodine, Iron, Iron, Manganese, Molybdenum, Selenium, zinc
Critical Micronutrients Function
Bone health
Antioxidants
oxygen Transport
Enzyme Function
Immune Function
Electrolytes in Blood
Other Tissue Function
where is the majority of calcium in the body
99%- Part of bone structure and in calcium bank
body fluids 1%
blood, Extracellular fluid and muscle and other tissue
Calcium RDAs
1-10 yrs 800mg/d
11-17 1200mg/d
18+ 800mg/d
pregancy 1200mg/d
Lactation 1200mg/d
Foods containing calcium
125ml of milk
cheese
youghurt ( 1 small carton)
cottage cheese
canned sardines
6 medium slices of brown bread
5-6 servings of green leafy veg
Calcium Absorption and Metabolism
-Calcium concentrations are tightly controlled
-If levels are too high or low ( intestines , kidneys and bones respond)
- Vitamin D , Parathyoird Hormone(PTH), calcitons serves to increase or decrease plasma concentrations.
Metabolic Function 1 of calcium
Extraskeletal Calcium
-Vasular contraction and vasodilation
muscle contraction
nerve transmission
Blood clotting
Metabolic Function 2
Normal Skeletal growth
- bone turnover/ remodelling
-Formation exceeds breakdown in periods of growth
-early/middle adulthood both processes relatively equal
-Aging adult, bone breakdown exceeds formation
How to determine Calcium Status
Dexa
- bone mineral content
bone mineral density
Osteoporosis Definition
Normal: BMD within 1 sd of young adult referance mean for the population
Osteopenia: BMD within -1 and -2.5SD
Osteoporosis: BMD more than -2.5
Calcium Deficiency
Osteoporosis and reduced bone mass
Calcium Toxicity
Kidney stones, Calcification of soft tissue, Absorption of mineral (fe, Zn)
Magnesium Foods
whole grains, legumes, Green leafy veg
Magnesium RDA
320ug women
420ug Men
Magnesium Metabolic Function
> 300 Enzymes reaction
- Glucose—Pyruvate
- Beta oxidation of fatty acids ( breakdown of FAs
-protein synthesis
Bone Development and maintenance ( structure)
DNA synthesis
ATP Production
Muscle contraction and blood clotting
Support Normal function of Immune system
Magnesium Deficiency
Not a problem in healthy population
- Rare genetic abnormality
-hypocalcemia ( blood) and hypocalciuria ( urine)
- Abnormal Neuromuscular Functions
Magnesium Toxicity
Not usually from food intake
- change in mental status, nausea, diarrhoea, muscle weakness , extremely low blood pressure
Phosphorus Make up in the body
Skeleton (85%)
Soft tissue ( 15%)
PHOSPHORUS foods
Milk, cheese, youghurt, eggs, chicken, beef, turkey, salmon,
Phosphorus RDAs
1-10yrs 300-400mg/d
11-17yrs 625-775mg/d
18+ 550
pregnancy 950
Phosphorus Metabolic Function
Structure
Phosphorus occurs as Hydroxyapatite in bone
-phospholipids, major component of most biological membranes are important for lipid transport
- Part of DNA
More Phosphorus Metabolic Function
Maintains Ph buffer ( acid or alkali)
energy storage ( ATP; phosphate groups )
phosphorylation ( activation of enzymes )
Phosphorus Deficiency (rare)
Hypohosphatemia
Anorexia, anaemia, muscle weakness, rickets , increased infection
Phosphorus Toxicity
Hormone Control of calcium
calcification of tissue, particularly the kidneys
What composition in the Body
45-70% water
- Adipose 10%
- Lean 76%
What is body water made up of ?
Electrolytes- sodium, potassium, calcium, Magnesium, Chloride, Phosphate
What mineral is the principal positively charges
Potassium
What mineral is positively charged in extracellular fluid
Sodium
What is the membrane potential ?
The concentration difference between potassium and sodium across cell membranes creating an electrochemical gradient
How is membrane Potential maintained ?
ion pumps in the cell membrane
Sodium/ Metabolic Metabolic function
Electrolytes, work with NaCl to maintain fluid balance.
During nerve impulse transmission and muscle contractions potassium and sodium switch places .
Na+/k+ -ATPase pump
restores intracellular and extracellular concentrations
NaCl metabolic function ; Electrolytes
Na+ and Cl- predominate in extracellular fluids.
Potassium and phosphate intracellular fluids
NaCl Function 2
Move across cell membrane by active transport
water moves to areas of high Na+ and/or Cl-
body couples active transport of ions with passive movement of water to regulate fluid balance in various fluid compartments of the body.
NaCl Function
Sodium:
-Nerve conduction, Muscle contraction
- active cellular transport
- (Na+/K+ ATPase pump)
-Formation of mineral apatite of bone (75%) chloride
- Production of HCL in the stomach.
NaCl Absorption and Metabolism
-Bioavailability is high
One absorption mechanism involves glucose.
-some absorbed in the colon
- major extretion route is urine, and sweat
NaCl absorption and metabolism
blood levels tightly controlled:
- hyponatremia( ^aldosterone- kidney retain Na)
-hypernatremia (low aldosterone- Na excreted in urine)
Potassium
Major INTRAcellular electrolyte
- 905 absorbed
- as with sodium the kidney regulates excretion
-aldosterone has opposite effect ( ^ NACl, low K)
- excreted in urine
Potassium foods
Legumnes, Nuts, meat, fish, bannas spinach and potatoes
NA, CL, K deficiency
rare
nausea, muscle cramps, confusion
