Transcript Water and Minerals

Nutrients in Bone Health
Calcium, vitamin D supplements
good for bones – if you take them
Bone Health
• Bone structure
– Provides strength to support the body
– Allows for flexibility
– Contains about 65% minerals providing the
hardness of bone
– Contains 35% organic structures for strength,
durability, flexibility
– Collagen: fibrous protein in bone tissue
Bone Health
• Bones develop through three processes:
– Bone growth – increase in bone size;
completed by age 14 in girls and age 17 in boys
– Bone modeling – shaping of bone; completed
by early adulthood
– Bone remodeling – reshaping of bone
Bone Health
• Bone remodeling involves:
– Resorption – surface of bones is broken down
• Osteoclasts – cells that erode the surface of bones
– Formation of new bone by cells called
osteoblasts
• Osteoblasts produce the collagen-containing
component of bone
Bone Health
Calcium
• Roles:
– 99% in bones and teeth
– 1%
• Cell membranes: regulates transport of ions into
and out of cells
– Nerve to nerve transmission
» Nerve to muscle transmission
• Helps hold cells together
• Blood Clotting
• Co-factor for several enzymes
Calcium: Blood Levels Highly
Regulated: 4 ways
• 1. Protein-bound Ca released to become
available for use by cells
• 2. Increased Calcium absorption from gut
through activation of Vitamin D
• 3.Increased Calcium released from the
bone through parathyroid hormone
activation of Vitamin D
• 4. Kidneys conserve Calcium
Calcium RDA 1000-1200 mg/day
for Adults
• Foods rich in Calcium:
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1 cup milk:
1 oz cheese:
1/2 cup spinach:
1 orange
1 cup Yogurt
(fat free or low fat)
300 mg
200 mg
106 mg
52 mg
350-400mg
Calcium Deficiency
• Rickets: in children. Same as Vitamin D
deficiency
– Bow legs, poor bone formation
• Osteomalacia: in adults. Same as Vitamin D
deficiency
– poor bone formation
• Osteoporosis: Multiple causes
Calcium and Osteoporosis
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Low Calcium intake
Poor Vitamin D status
female
family history
small skeleton
menopause
smoking
high animal protein
drinking alcohol bed rest
white/Asian
MerckMedicus Modules: Osteoporosis - Pathophysiology
Does your child have a
drinking problem?
Fruit and veg boosts bone strength during teenage
years
Vitamin D Functions
• Works in three ways:
– 1. Increases Calcium Absorption from the G.I.
tract
– 2. Helps to withdraw calcium from bone
– 3. Increases calcium retention in the kidney.
Sources of Vitamin D
• Body makes it own:
– Dehydrocholesterol in the skin exposed to sunlight
• Energy transforms it into a pre-vitamin D molecule
• Body heat provides energy to change pre-vitamin D into
inactive Vitamin D
• Inactive Vitamin D activated in two steps
– First, in the Liver
– Second in the Kidney
Netrition Home Page
Vitamin D
Sources of Vitamin D
RDA = 5 ug-15 ug
• In foods:
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Fortified milk: 2.5 mcg/cup
1 egg = 0.7 mcg
3 oz shrimp = 3 mcg
1 tsp margarine = 0.5 mcg
USATODAY.com - How to get vitamin D?
Vitamin D Deficiencies
• In children: Rickets
– malformed bones, bow legs
• In adults: osteomalaciaVitamin D improves symptoms of knee
osteoarthritis
• most often occurs in women with low Ca intake,
repeated pregnancies, low sun-exposure, and
long breastfeeding with infants
– loss of Calcium from bone and change of shape
• USATODAY.com - Vitamin D reserach may have
doctors prescribing sunshine
Rickets:
Vitamin D
deficiency
in Children
Vitamin D Toxicity:
• Most potentially toxic of all vitamins!!!!
– As little as 4 to 5 X RDA can be associated with toxic
symptoms
• minor: diarrhea, headache, nausea
• major: calcium deposits in soft tissues of heart, kidney,
arteries
– Major concern: those who take Vitamin D supplements
• If some is good, more is NOT better!!!!!
Vitamin K
• Blood coagulation
– coenzyme
• Deficiency
• Toxicity
Phosphorus
• Bone formation
• Deficiency
• Toxicity
Fluoride
• Becomes part of crystalline deposits in bones
and teeth
– In teeth, resistant to tooth decay (dental caries)
– 1 part per million in water supply optimum resistance
– Higher than that can result in tooth mottling
• Brown coloration on teeth
– Much higher (18 ppm) can result in fluoridosis
• Bone malformation
Tracking Fluoride in the National Food Supply / November 9, 2004 / News from the
USDA Agricultural Research Service
Nutrients in energy metabolism
and blood health
B Vitamins
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Correct names and common names
Thiamin
B1
Riboflavin
B2
Niacin
nicotinic acid
B6
pyridoxine
folacin
folate, folic acid
B12
cobalamin
B vitamins: Correct names
• pantothenic acid
• biotin
no other
no other
• B vitamins act as coenzymes
– Help to complete the correct shape of the
molecule
– Many help to metabolize glucose to release
energy
B Vitamins
• Coenzyme function
– Prosthetic Group: physically become part of an
enzyme complex
– Others are more loosely attached
– May be part of the active site in the enzyme.
Vitamins and Metabolism
B Vitamins
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Thiamin
Riboflavin
Vitamin B 6 (pyridoxine)
Folate
B vitamin deficiencies
• Thiamin: beriberi
– symptoms: mental confusion, muscle weakness and
wasting, edema, enlarged heart
• Riboflavin:
– symptoms: personality changes, cracks at the corners
of your mouth(cheilosis), tender tongue(glossitis)
• Folacin:
– Symptoms: megaloblastic, macrocytic anemia,
Niacin
• Part of NAD+
– helps metabolize glucose
– without Niacin, this breakdown of glucose stops
– Slows energy release: 4 D’s of Niacin deficiency (called
pellagra:
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Dermatitis: skin inflammation
Diarrhea: poor absorption
Dementia: no energy to think
Death: if untreated
Vitamin B 12
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Blood formation
Homocysteine
Nerve damage
Deficiency
– Atrophic gastritis
– Pernicious anemia
Megaloblastic anemia
Vascular Disease
• Folate and vitamin B12 are required for the
breakdown of the amino acid homocysteine.
• Low folate and vitamin B12 intake may cause an
increased level of homocysteine.
• High homocysteine levels are associated with
greater risk of cardivascular and
cerebrovascular disease.
B vitamin Toxicities: Rare
• B6
– Symptoms: with very high doses sensory nerve
disorders; may interfere with nerve impulses and
heart beat
• Niacin
– Symptoms: skin flushing, nausea, jaundice, liver
dysfunction
• Some individuals with high serum cholesterol are treated
with pharmacological doses of niacin
Iodine
• Regulator
– Thyroid hormones
• Deficiency
• Toxicity
Iodine Deficiencies
http://www.forbes.com/forbeslife/he
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533494.html
Blood Health
Trace Minerals: Micro minerals
• One definition: less than 0.1 gram(100
mg/day) need in the diet
– Some trace minerals:
• Iron (Fe)
• Zinc (Zn)
• Copper (Cu)
Iron
• Component of hemoglobin and myoglobin
– hemoglobin carries oxygen in blood
– myoglobin stores oxygen in muscle cells
• Deficiency:
– RDA set at 18 mg/day for females and 8 mg/day
for males
– If iron stores exhausted, iron deficiency
anemia
• microcytic, hypochromic anemia
• reduced Hemoglobin synthesis, RBCs are small and
Iron
Iron Absorption
• Most iron we eat doesn’t get absorbed
– What helps?
• vitamin C
• MFP factor: some factor in meat, fish and poultry
helps absorb iron
• need for iron
– What hurts absorption?
• tea
coffee
• Calcium and Phosphorus
• phytates and fiber and oxalates
Factors Affecting Iron Absorption
• Increase
• Decrease
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Gastric Acid
Heme iron
Demand
Low body stores
MPF
Vitamin C
Phytic Acid
Oxalic Acid
Polyphenols
Full body stores
Excess of other min.
Reduced gastric acid
Some antacids
Iron: Method of Absorption
• Iron in food
– Absorbed into cells that line GI tract
– If blood levels of iron are low
• iron picked up from cells by the blood and carried
to places where RBCs are made
– If blood levels of iron are ok
• iron stays in cells lining the GI tract
– In 3 to 5 days the cells are worn out and fall into the
lumen of the GI tract and mix with the remains of
digestion
Iron Absoption
Iron Overload
• 2 Types of Overload
– 1. Hereditary Defect: Hemochromatosis
• Very efficient absorption
• High circulating Fe which is laid down in tissues of
liver, heart and causes damage
– 2. High Iron ingestion: Hemosiderosis
• Even with control of absorption, high intake can
result in toxic side effects
• We don’t have a good mechanism of getting rid of
absorbed iron
Iron Sources
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4 oz of lean roast = 3 mg
4 oz liver = 7 mg
1/2 cup beans = 4.15 mg
1 cup broccoli = 1.12 mg
1 slice mixed grain bread = 0.8 mg
1 cup raisins = 3.12 mg
Zinc
• Part of nearly 100 enzymes
• Role in immune function
• Absorption affected by zinc status,
phytates, iron
• Hinders absorption of copper and iron
• Sources: red meats, eggs, vegetables
Zinc Deficiency
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Growth delay
Altered digestive function
Impairs immune response
Vitamin deficiencies
Loss of appetite
Slow wound healing
Dry, scaly skin
Copper
• Coenzyme
– Part of ceruloplasmin
• Deficiency
• Toxicity