Major Minerals
in Bone and
Protein
By Jennifer Turley and
Joan Thompson
© 2016 Cengage
Presentation
Overview
• Functions, deficiency,
toxicity & food sources of
Ca, P, Mg as bone minerals.
• Osteoporosis types & risk
factors.
• Functions, deficiency,
toxicity & food sources of S
as a protein based mineral.
Calcium Functions
• Bone & tooth structure.
• Blood clotting, muscle
contraction, and nerve
conduction.
Calcium (Ca) Deficiency & Toxicity
Deficiency
Adequacy
Toxicity
(<66% of DRI)
DRI: 1,000-1,200
mg/day
(>UL)
Approx. <660-790 mg/day
>2,500 mg/day
RDI: 1000 mg
Osteopenia
Bone & tooth: stunted growth
in children, low bone density,
osteoporosis
Normal
Bone and tooth
structure, muscle
contraction, nerve
conduction, blood
clotting
Hypercalcemia
GI System: constipation,
reduces absorption of iron,
magnesium, zinc, and
phosphorus.
Other: kidney stones,
calcium deposits in soft
tissues
Adult deficient, adequate, toxic values
Calcium: Food
Sources
• Diary product sources: milk, yogurt, &
cheese and foods made with diary
products like pudding.
• Non dairy sources include fortified foods
like soymilk and cereal, canned fish with
the bones, spinach, turnip greens, tofu,
broccoli, and kidney beans.
• The bioavailability of Ca is highest (~50%)
from cruciferous vegetables, moderate
(~30%) from dairy products & Ca fortified
foods, low (~20%) from beans, nuts &
seeds & lowest (<5%) from spinach.
Calcium in Dairy Foods
~ 30% bioavailability
Calcium supplements should be taken if chronic low dietary
intake occurs
Calcium in Non Dairy Foods
<5 to >50% bioavailability
Calcium supplements should be taken if chronic
low dietary intake occurs
Calcium Supplements
• Calcium carbonate. Better absorbed when taken with
food.
– 40% Calcium
– 500 mg tablet provides 300 mg Carbonate & fillers
– 200 mg Calcium
• Calcium citrate. Can be taken on an empty stomach.
– 21% Calcium
– 500 mg tablet provides 394 mg Citrate & fillers
– 105 mg Calcium
• Avoid:
– Oyster shell, coral, bone meal, calcium phosphate, anti-acids
supplements due to poor absorption, non-optimal design, and/or
possible contamination.
Phosphorus Functions
• Bone & tooth structure.
• Important for the cells genetic
material (DNA),
phospholipids in cell
membranes, energy transfer
(ATP), phosphorylation
reactions, & buffering
systems (maintaining pH).
Phosphorus (P) Deficiency & Toxicity
Deficiency
Adequacy
Toxicity
(<66% of DRI)
DRI: 700 mg/day
(>UL)
Approx. <460 mg/day
RDI: 1,000 mg
>4,000 mg/day
Hypophosphatemia
Bone & tooth: bone
pain
GI System: anorexia
Neuro-Musccular:
muscle weakness
Other: general debility
Normal bone & tooth
structure, DNA, ATP,
phospholipids,
phosphorylation
reactions, and
buffering systems.
Hyperphosphatemia
GI System: reduced
calcium absorption
Other: calcification of
non-skeletal tissues.
The body strives for a calcium
to phosphorus ratio in the blood
stream of 1:1
Adult deficient, adequate, toxic values
Phosphorus:
Food Sources
• Animal products
• Processed foods
• Preserved foods
Phosphorus in Foods
Adult DRI: 700 mg/day
Magnesium
Functions
• Is needed to build bone, teeth, &
proteins.
• Is a cofactor for more than 300
different enzymes.
• Functions in muscular contraction,
blood clotting, and nerve impulse
transmission.
Magnesium (Mg) Deficiency & Toxicity
Deficiency
Adequacy
Toxicity
(<66% of DRI)
DRI: 310-420 mg/day
(>UL from supplements)
Approx. <205-280 mg/day
RDI: 400 mg
>350 mg/day
Rare in healthy people.
Associated with hypocalcemia
Normal bone, tooth,
and protein building;
Central Nervous System: enzyme action,
seizures
muscle contraction,
Neuro-Musccular: muscle blood clotting, and
cramping, hyperexcitability nerve impulse
Other: vitamin D
transmission
metabolism interference
From supplements and
laxatives
GI System: diarrhea,
nausea, abdominal
cramps, paralytic ileus
Other: metabolic
alkalosis, hypokalemia
Adult deficient, adequate, toxic values
Magnesium: Food
Sources
• Mostly plant foods: nuts, legumes,
whole grains, dark green leafy
vegetables, chocolate, and cocoa.
• ~80% lost in grain processing.
• Is not added back to processed foods.
Magnesium in Foods
Adult DRI: 310-420 mg/day
Osteoporosis the silent
bone stalker
TYPE 1
TYPE 2
Postmenopausal
Senile
Onset age
50-70 years
>70 years
Bone loss
Trabecular
Trabecular & cortical
Gender
Women:Men
Women:Men
6:1
2:1
Fracture site Wrist & Spine
Cause
Hip
Estrogen loss
Reduced calcium
following menopause absorption,
in women.
increased
demineralization of
Testosterone loss
bone, increased
with age in men.
propensity to fall.
Bone
Trabecular Bone:
– The lacy inner structure of
calcium crystals that supports the
bone’s structure & provides a
calcium storage bank.
Cortical Bone:
– The very dense bone tissue that
forms the outer shell surrounding
trabecular bone and comprises
the shaft of a long bone.
Types of Fractures
• Wrists (least severe)
– Most occur at age 50 or older
– Is an early warning sign for
osteoporosis.
• Spinal vertebrae (chronic back pain)
– More likely at ages 55-75 years
– Fractures occur from bending or
lifting
– Several fractures leading to loss of
height & spinal curvature
• Hips (most serious)
– Most occur at 70 years or older
– 20% die with in 4 months
– 50% become institutionalized
Peak Bone Mass
• Bone mass gained up to~ 25 yrs.
• Bone mass stabilized up to~ 40
yrs.
– Exact age depends on physiological
conditions.
• Bone mass is lost after ~50 yrs.
– Exact age depends on physiological
conditions.
Osteoporosis Risk Factors
• High Protein & Phosphorus intake
• Low calcium, vitamin D,
magnesium, and fluoride intake
• Genetics (family history, small
frame size)
• Lack of Exercise
• Very high fiber intake
• Smoking & Alcohol
• Menopause
Sulfur Functions
• Needed for the biosynthesis of sulfur
and sulfate containing compounds.
• A component of organic compounds
biotin, thiamin, cysteine, methionine,
glutathione, taurine, and insulin.
• Helps stabilize protein shape and
structure by forming disulfide bridges.
Sulfur (S) Deficiency & Toxicity
Deficiency
Adequacy
Toxicity
Not Established
DRI & RDI
UL is Not
Established
Not Established
Sulfur has no known
deficiency state.
Protein deficiency
would appear first.
Normal
biosynthesis of
sulfur and sulfate
containing
compounds
GI System: osmotic
diarrhea and may
contribute to
inflammatory bowel
disease such as
ulcerative colitis
Sulfur: Food Sources
• Dried fruit, commercial
breads, soy, sausages, tap
water, some beverages, and
protein-containing foods.
Some
Summary Points
• Ca, P & Mg are important for bone &
tooth structure while Mg & S are
important in protein structure.
• These minerals have other critical
functions in the body.
• Type 1 & 2 Osteoporosis.
• Deficiency &/or toxicities & food sources
are identified for these minerals.
References for this presentation are the same as
those for this topic found in module 5 of the
textbook