Micronutrients For Bone Bealth Flashcards
Bone structure
Cortical- outer hard shell, compact and very dense
Trabecular bone- inner lacy matrix of calcium crystals (Ca storage bank), porous
Vitamin D
Maintains calcium and phosphorous balance in conjunction with parathyroid hormone
Immune function- enhances WBC
Muscle function
From sunlight, fish, meat, milk, fortified marg
Elderly, dark skinned women, veiled women, adolescents in winter
Excess- hypercalcaemia
Vitamin K
Blood clotting
Bone turnover
Green leafy veg, veg oils, milk, meat
Deficiency- impaired blood clotting, easy bruising, nosebleeds
Calcium
Bone and teeth structure
Nerve impulse transmission
Blood clotting
Dairy, fish with edible bones, fortified products
Deficiency
Osteomalacia
Rickets
Osteoporosis
Calcium regulation
- Blood calcium drops
- Parathyroid gland releases PTH
- PTH stimulates kidney to activate vitD
- Active vit D increases intestinal absorption of calcium and phosphorous
- PTH and active vit D stimulate bone resorption- bones release calcium and phosphate to blood
- PTH triggers decreased urinary excretion of calcium and increased urinary excretion of phosphate
- blood calcium increases
- thyroid gland releases calcitonin and parathyroid gland decreases release of PTH
- calcitonin inhibits activation of vitamin D in the kidneys
- absence of activated vit D limits calcium absorption
- calcitonin inhibits osteoclasts. Osteoblasts become more active and calcium is deposited in bones
- calcitonin prevents calcium reabsorption in kidneys
- blood calcium decreases
Phosphorous
Bone and teeth structure
Role in maintaining fluid balance
Component of ATP
Milk, meat, eggs
Deficiency- hypophosphataemia
Loss of appetite
Dizziness
Bone pain
Magnesium
Bone and teeth structure
DNA and protein synthesis
Muscle contraction
Leafy green veg, whole grains, seeds
Fluoride
Strengthens bones and teeth by forming fluorapatite
Replaces hydroxyl group in hydroxyapatite crystal that is formed from calcium and phosphorous during mineralisation of bones.
The fluorapatite makes the teeth more resistant to decay,
Thus prevents tooth decay
Tap water, fish and teas
Antioxidants
Molecules and enzymes that protect living organisms from oxidative damage by preventing formation of free radicals or removing them before they cause damage
Vitamin E
Acts as an antioxidant
protects PUFAs and LDL from oxidation
Protects RBC membranes and lung cells
Enhances immune function
Meat, poultry, fish, nuts and seeds
Deficiency-
Muscle weakness
Peripheral neuropathy
At risk- premature babies, fat malabsorption, avoidance of dietary fat
Vitamin C
Antioxidant activity
- acts as electron donor to minimise damage by free radicals
- prevents formation of N-nitroso compounds in stomach
- protect against lipid oxidation
- collagen synthesis, iron absorption and immune function
Citrus fruits, broccoli, leafy greens
Deficiency- scurvy
At risk- impoverished, elderly, alcoholics, smokers
Vitamin A
Vision- maintains cornea, participate in conversion of light to nerve impulses at the retina
Protein synthesis and cellular differentiation
Reproduction and growth
Deficiency: night blindness, increase infectious diseases
Carrots
Selenium
Cofactor for antioxidants
Prevent free radical formation
Seafood, meat, whole grains, nuts, vegetables
Selenium toxicity- garlic odour in breath, GI disorders
Deficiency rare- Keshan disease (heart disease)
High risk- elderly, dependant of food grown in SE poor soil
