Bone Health
Minerals
Fat-Soluble Vitamin
Calcium
Phosphorus #
Magnesium
Trace Minerals
Vitamin D (calcitriol)
Vitamin K
Unique due to 2 Sources
Bones
Role
Absorption
Enhanced Absorption
Decreased Absorption
Maintenance
Formation
Function
Deficiency
Functions
Toxicity
Food Sources
Bone formation and maintenance
Bone & Teeth
Blood & Tissue Magnesium
Hypertension
Support normal immune function
Protects against high blood pressure - acts as vasodilator
Lower rates of heart disease in regions where people drink hard water
More than 300 enzymes systems need Magnesium
Nerve transmission an muscle contraction
Blood clotting
Functions
Stabilizes Phosphate groups in ATP
Absorption
In duodenum
needed for neurotransmitter activity regulated via Mg-dependent adenylate cyclase enzyme system
proportional to needs
50% absorbed during pregnancy
children absorb 50%
Enhanced by lactose and Vitamin D #
Exogenous
Inhibits muscle contraction - blocks calcium ion channels
Mg inhibits blood clotting (ion antagonist to calcium) #
Protein, fat, and nucleic acid (DNA) synthesis
Endogenous
bone formation and maintenance
Vitamin-Action
Hormone-Action
Absorption
Function
Nerve Transmission and Muscle Contraction
Blood Clotting
Protection Against colon cancer
Fluid Balance
Blood and Tissue Phosphorus
Mg indirectly affects calcium balance as it is needed for the action of vitamin D and the production of parathyroid hormone #
Converted to pre-Vitamin D3
Activated when exposed to sun
Inactive form of Vitamin D3
Deficiency
Degenerative Bone Disease Osteoporosis
Risk Factors
Mg used in mineral crystal structure of bone - can replace Ca in hydroxyapatite #
Structural Support
Genetics/Race
Functional Characteristic
Muscle Attachment
Jaw Bone and Teeth
Age/Gender/Hormones
Organ Organization
Physical Activity
Body Weight
Bone acts as a reservoir of Mg
Contains Osteoid
Smoking and Alcohol
Inorganic Materials (65%)
Mg helps hold Ca in teeth this reducing dental caries
Manufacture of RBC, WBC
Prevention
Estrogen Therapy
Vitamin D Therapy
Calcitonin Therapy
Bisphosphonate Therapy
Milk & Milk Products
Mineral Matter
Organic Matter
Strength, Rigidity
Flexibility
Reduction
Develops slowly - Mg is stored in bone
Hydroxyapatite crystals Ca10[PO43-]6[OH]2 : formed by dietary calcium and phosphate salt #
severe deficiency symptoms rarely seen in healthy individuals
Symptoms
Introduction
Leafy greens, avocado, beets
Whole grains, nuts, seeds, tofu, legumes
Irregular heart beat
loss of appetite
Weakness
desorientation
hypertension
risk for deficiency increases with:
Heavy perspiration over a long period of time
Prolonged vomiting and/or diarrhea
Prolonged use of diuretics
Kidney disease
Alcoholism
Unknown adverse effects with supplemental intake
Pharmacological dosage may cause symptoms similar to Mg deficiency #
Deficiency
unlikely to happen with varied and well-balanced diet
Toxicity
Major intracellular anionic electrolytes
helps to maintain proper electrical and fluid balance
15% of body is Phosphorus
Phosphate (phosphorus salt) acts as a buffer
Intercellular functions
High energy phosphate bond (ATP)
Phospholipids in cell membrane and lipoproteins - transports fat-soluble nutrients in body
Enzyme Reactions (coenzymes needed for energy metabolism)
B-Vitamins activate when phosphate group is added
DNA & RNA
Essential for Growth
component of Hydroxyapatite crystals #
symptoms
Neuromuscular malfunctioning
Skeletal malfunctioning
Hematological malfunctioning
Renal malfunctioning
There's no true toxic effect caused by high Phosphorus intake
Adverse effects with combination of high Phosphorus intake and low Calcium intake #
80-90% of dietary Phosphorus is absorbed
Food Sources
animal protein foods + milk and milk products
UL - 4000 mg/day
RDA for Adults - 700 mg/day
Phosphorus supplementation not needed - plenty in diet
Legumes, cereal, bran, nuts
DRI (supplemental) Adults - 350 mg/day
Fluoride
Role in Bone and Teeth Mineralization #
Fluoride best taken during bone & teeth development
Deficiency
More resistant to acid erosion decay
Toxicity
Increase in dertal caries
Flurosis
White specks, molting, or brown streaks on teeth
High Fluoride intake during teeth development
Causes abnormal hardening of skeleton making bones more brittle
Causes stiffness and joint pain
UL Adults - 10 mg/day
A! - Males 4 mg/day; Femaile 3mg/day
Food Sources
Brewed tea, tap water
Seafood, seaweed, shellfish, fish
Non-food Sources
Toothpaste
Chewing gum
Mouth wash
In duodenum
Depends on active vitamin D #
estrogen enhances synthesis
Lactose enhanced
Absorption proportional to needs
50% absorbed during pregnancy for growth
50% absorbed in children for growth
High fibre diets
Phytic acid
High fat intake
vitamin D deficiency #
Polyphenols
Flows into muscle cell
Flows out of muscle cell
Causing contraction
Causing relaxation occurs
Formation of fibrin
Consumption >1250mg/day
Weightloss
Stimulate hormone action
Helps break down stored body fat
Stimulated by parathyroid hormone
Hormone calcitonin
reduces amount that leaves bone
formation hydroxyapatite crystals #
provides strength and rigidity to bones
form other mineral crystals
menopause for women 40 years and older
girls that are unreasonably thin
eating disorders
extreme dieting and exercise during adolescents
30 years of age men begin slow bone loss
African Americans have more dense bones than Caucasian Americans
Lack of physical acivity
extreme dieting and exercise during adolescents
confined to bed
underweight women
smokers tend to have lower body
alcoholics tend to have slower bone formation
alcohol is toxic to bone
used at menopause
slows the rate of bone loss
actives form of vitamin D
increases Calcium absorption
inhibits loss of minerals from bone
inhibites osteoclast activity
Young Women
Adult Women and Men
Women and Menopause
regular menstruation and ovulation
moderately active lifestyle
limited exposure to sun
moderately active lifestyle
reduce smoking
reduced amount of alcohol
appropriate therapy and adequate amount of intakes
remain physically active
Toxicity
Hyperparathyroidism
excessive production and secretion of parathyroid hormone
causes kidneys to retain calcium in
blood
causes bone to release calcium into blood
Hypercalcemia
calcium deposits into soft tissue
high blood and urinary Calcium levels
damage to organs
most effected
those with kidney diease
Sources
Supplements
Food Sources
milk products
calcium fortified products
soy beverage
milk
cheese
yogurt
fortified orange juice
tofu
skim
2%
Leafy Vegtables
Canned Fish
Hard water
Bone Marrow produces
Organic Materials (35%)
Mineral Crystals
Protein matrix (Collagen), nerves, cartilage, and connective tissue
Provides Flexibility
Provides Strength and Rigidity
red blood cells, white blood cells, and platelets
Hydroxyapatite crystals
Cortical Bone
Trabecular Bone
ivory-like and dense
small bones and outer surface of long bones
slow turnover, ~80% of entire skeleton
lace-like texture
~20% of skeleton
dynamic, ends of long bones, spinal vertebrae
sensitive to hormones associated with Calcium
2 types of Bone Cells
osteoblast cells
osteoclast cells
break down bones
build bones
3 Process of Bone Development
Bone Growth
Bone Modelling
Bone Remodlling
osteoblasts more active than osteoclasts
Size and Length of bones increase
bones take on specific shape
Bone turn over, density is affected
100% bone rebuilt during early years
~15-30% bones rebuilt each year
Osteoclast resorption requires vitamin A
Chylomicron remnant deliver Vitamin D to liver #
Calcium Balance
Regulated by absorption
blood Calcium doesn't reflect Calcium Status
Blood Calcium homeostasis kept at ±3% of 10mg Ca/dL
Regulated by 3 hormones
Calcitriol (active Vitamin D) #
Parathyroid Hormone
Calcitonin
Low Blood Calcium Levels
High Blood Calcium Levels
Parathyroid gland secretes #
Kidney acts on osteoclast cells to raise blood Calcium, activates #
Regulates Bone Calcium and Bone Metabolism in 3 Sites #
Intestine
Kidneys
Bones
increase absorption of Calcium
Conserve Calcium
Osteoclast cause bone to release Calcium into blood
lead to calcium tetany in muscles
lead to calcium rigour in muscles
Thyroid gland secretes hormone #
causing decrease action of osteoclasts, reducing the amount of calcium leaving bone and entering into the blood
Measuring Bone Density
Dexa-Dual Energy X-Ray Absorptiometry
Ultrasound
sound waves, measure bone density in heel
non-invasive, painless, quick
screening tool, not diagnostic
pDEXA- Peripheral Dual Energy X-Ray Absorptiometry
x-rays used to measure bone density in heel, wrist or finger
non-invasive, painless, quick
screening tool, not diagnostic
gold standard measure
non-invasive, painless, quick (20 minutes)
very low x-ray energy for entire body scan
results compared with same age-racial group
T-score generated
+1 to -1 is normal
-1 to -2.5 (osteopenia, low bone mass, increased risk of fracture)
-2.5 (osteoporosis, increased risk of fracture)
Vitamin D is pro-vitamin (inactive) must be activated in liver and kidney to form
~ 50%
incorporated into chylomicrons for transport-> lymph -> blood
Immune Function
calcitriol associated with maturation of immune cells
nervous system, muscle, skin, reproduction
Deficiency
Children
Adults
Osteomalacia
Rickets
poor mineralization and shaping of bones, bowed legs, malformed ribs
breast milk low in vitamin D
little exposure to sun
osteoid is matrix which minerals are deposited to form bone
osteoid doesn't mineralize properly
Caused by
kidney, liver, intestinal diseases
low intake of Vitamin D and little exposure to sun
repeated pregnancies
Treatment
increase Vitamin D intake and sun exposure
Toxicity
Causes #
excess solar exposure: non-toxic
Food intake: safe, non-toxic at normal intake
Effects
Hypercalcemia
calcium deposits into soft tissues
irreversible damage to organs
Children at higher risk
Supplements
tablet, softgels, liquid
available as D2 (ergocalciferol) or D3 (cholecalciferol)
Doses
Absorption
adults over 50
400 IU (10 μg) of vitamin D daily
~50-80% of ingested amount
fish oil are high in vitamin D and A
Food Sources
Animal Products
egg yolks, liver, fish, and fish oils
Fortified Food
milk, margarine, orange juice, yogurt
stable to heat, storage, and processing
Recommendation
RDA
Adults (0-70 yr): 15 μg/day* (600 IU)
71+yr: 20μg/day(800IU)
RDA assumes no solar synthesis
UL
all adults: 100 μg/d (4000 IU)
Family of compounds
essential for blood clotting, coenzyme for synthesis of protein
40-80% absorbed, with dietary lipids; incorporated into chylomicrons
endogenous sources
bacterial synthesis in the GI tract
exogenous sources
antibiotic use can increase dietary need
Roles
quinones - plant (phyllo) and animal (mena) sources
Calcium Mineralization in Bone Matrix
Blood Clotting
required by osteoblasts to synthesize osteocalcin
necessary for proteins in the production of fibrin, blood clotting protein
important for infants with sterile GI tract
receive a dose of vitamin K at birth to prevent hemorrhaging
Deficiency
Infants
low level at birth; low level in breast milk
low levels of gut bacteria to make vitamin K
Adults
rare, due to antibiotic use
excessive intake of vitamin E impairs the role of vitamin K in blood clotting
Toxicity
rare, food sources are considered non-toxic
Symptoms
RBC hemolysis, jaundice, brain damage
Recommendation
AI
adult males: 120 μg/d; Females: 90 μg/d
UL: none
Food sources
Green leafy vegetables
kale, peas, broccoli, green beans
Animal products
liver, eggs, milk
abundant in diet, bacterial synthesis in large intestine
very stable and resistance to cooking losses
if level falls, it will decrease the absorption of Calcium
if level falls, results in an increase in urinary Calcium
at low blood calcium level, calcitriol increase calcium blood levels
Role in multiple sclerosis
greatest cause of Vitamin D toxicity
not advisable to take Vitamin D supplements
Dietary Calcium and Phosphorus are essential for bone formation and maintenance #
adequate intake of nutrients that support bone health
Types
Doses
Absorption
Mineral-Mineral Interactions & Timing
Various forms: tablets, chewable, liquid
Common Supplements: carbonate, citrate, lactate, phosphate
Avoid: refined oyster shell, dolomite, coral or bone meal supplement
UL: 2500 mg/day
Greater than UL may lead to increased blood and urinary Calcium
maximum 500 mg Calcium/doses a day
~30% for all supplements (citrate ~35%)
Take Calcium Carbonate with food
Calcium citrate can be taken without food
take at time of low Calcium or Iron intake
decrease absorption of other minerals (iron, Magnesium)
take before bed
Recommended, but must be taken with consideration
Children are at greatest risk if they consume too much fluoride
Effected by
Genetics, Environment, Hormones, nutrients intake (calcium, phosphorus, magnesium, fluoride)
85% is used with calcium to form Hydroxyapatite crystals #
high calcium intake interferes with Magnesium absorption #
Most effected
Postmenopausal women
People with lactose intolerance
elderly
Very common in North America
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