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• Osteoporosis → Skeletal disorder characterized by decrease bone
mass and deterioration of bony microarchitecture.
• It is a multifactorial disorder in which nutrition plays role but does
not account for the totality of the problem.
• The result: Fragile bones and risk for fracture.
• BMD is reduced, bone microarchitecture is disrupted, and the
amount and variety of non-collagenous proteins in bone is altered.
• Many papers → describe studies of relationship of calcium intake and
bone health
• 52 investigator-controlled calcium intervention studies → two showed
better bone balance at high intakes, greater bone gain during growth,
reduced bone loss in the eldery, or reduced fracture risk.
• High calcium intakes → bone health.
• Most studies: based on dairy calcium.
• Higher calcium = higher dairy intakes → Connection between dairy
foods and bone health.
BACKGROUND
• Osteoporosis → Skeletal fragility → Characterized by
decreased bone mass and microarchitectural deterioration of
bone tissue → Increase risk of fracture.
• Fracture: In the form of cracking (as in a hip fracture), or
collapsing (as in a compression fracture of the vertebrae of the
spine).
• Spine, hips, and wrists are common areas of osteoporosis-
related bone fractures.
• Nutrition (calcium) plays an important role in protecting
against osteoporosis → development and maintenance of
bone mass and by maintaining normal postural reflexes
and soft tissue mass.
• Human needs calcium to stay healthy changes over
lifetime.
• Body's demand for calcium → greatest during childhood
and adolescence, during pregnancy and breast-feeding.
• Osteoporosis is a condition that features loss of the normal density
of bone and fragile bone.
• Normal bone: protein, collagen, and calcium.
• Bones that are affected by osteoporosis can fracture with only a
minor fall or injury.
• The fracture can be either in the form of cracking (hip fracture), or
collapsing (compression fracture of vertebrae).
• Spine, hips, and wrists: common areas.
• Etiological factors of primary osteoporosis → Family history
of fracture or low bone mass.
• Heritability of fracture as well as low BMD: 25-80%.
• Menopause → correlated with a rapid reduction in BMD →
Leads to fractures of the wrist, spine and hip.
• Hormone deficiency: testosterone, glucocorticoid or thyroxine,
and calcium and/or vitamin D deficiency → Increase risk of
osteoporosis.
• Underlying mechanism: imbalance bone resorption and
bone formation → Bone resorption is excessive, bone
formation is diminished.
• Bone matrix: osteoblast cells.
• Bone resorption: osteoclast cells.
• Bone remodeling → Influenced by nutritional and
hormonal factors.
• Calcium and vitamin: Required for normal bone growth.
• Parathyroid hormone → regulates composition of bone.
• Glucocorticoid hormones → Increase osteoclast.
• Calcitonin and estrogen → Increase osteoblast.
• Estrogen following menopause causes a phase of rapid
bone loss.
• Testosterone in men: Related to male osteoporosis.
• Dual energy X-ray absorptiometry (DXA): Gold standard.
• Diagnosis → BMD is less than or equal to 2.5 standard
deviations (T - Score).
WHO: Criteria for the Diagnosis of Osteoporosis (1)
CATEGORY CRITERIA (EXPRESSED AS T - SCORE)
NormalPatient BMD 1 SD of average peak young adult BMD (T-score, 0 to -1)
Osteopenia Patient BMD between 1 SD and 2.5 SD below average peak young adult BMD (T-score, -1 to -2.5)
Osteoporosis Patient BMD 2.5 SD below average peak young adult BMD (T-score, -2.5)
Severe Osteoporosis
Patient BMD 2.5 SD below average peak young adult BMD with fragility fractures
• Fractures: most frequent and serious complication.
• It often occur in your spine or hips — bones that directly
support your weight.
• Hip fractures: second most common type of osteoporotic
fracture → result from a fall.
• Hip fractures → disability and edeath from postoperative
complications.
• Wrist fractures from falls also are common.
• Spinal fractures can occur without any fall or injury
simply because vertebrae become so weakened that they
begin to compress.
• Compression fractures → severe pain and require a long
recovery.
Clinical risk factors for osteoporosis(4).• Previous vertebral fracture or low trauma appendicular
fracture• Post-menopausal woman not receiving HRT• Premature menopause at <45 year or male hypogonadism• Age > 65 year• Planned or current CS use of > 6 months• Low BMI: < 20 kgum2• History of low trauma maternal hip fracture at < 60 year• Other causes of osteoporosis, e.g. alcohol excess, RA,• Hyperparathyroidism, thyrotoxicosis
• Bone is living tissue → have same kinds of nutrient needs
of the body: for energy supply, protein and micronutrients.
• Bone growth → stunted ingeneral malnutrition bony and
abnormalities develop with deficiencies of protein, ascorbic
acid, vitamin D, magnesium, zinc, copper and manganese.
• Bone depends upon dietary intake → supply the bulk
materials → synthesis of the extracellular material:
composes > 95% of the substance of bone.
• Bulk materials: calcium, phosphorus and protein.
• Extracellular material of bone: protein and calcium
phosphate crystals.
• Calcium is lost through shed skin, hair, nails, sweat, urine
and digestive secretions (range 4-8 mmol) → depending
physical activity and dietary constituents.
• Absorbed calcium input in an adult fails to match daily
losses → blood calcium levels begin to fall → increased
secretion of parathyroid hormone (PTH): resorbs bone
and releases into blood.
• This is relationship between low calcium intake and low
bone mass → respect to failure to achieve the genetically
programmed peak mass (calcium intake is inadequate),
and respect to losses of bone after maturity (ingested
calcium is not sufficient to offset daily loss from body).
FIGURE.. Plots of the cumulative incidence of fractures, redrawn from the studies of Chapuy et al (17) (right) and Dawson-Hughes et al (18) (left). In both cases, the upper line represents the placebo control subjects and the lower line represents the subjects treated with calcium and vitamin D. The shaded zones represent the reduction of fracture risk, which, as can be readily seen, starts with the beginning of treatment
• Fifty-two of these studies consisted of investigator controlled
interventions: 37 in adults, 14 in children or adolescents and 1
combining both age groups.
• All of the metabolic and physiologic studies showed that higher
calcium intakes produced better calcium retention or reduced bone
remodeling.
• Two of these metabolic balance studies used dairy products as the
calcium source.
• Several of the balance studies used dose-ranging
approaches to estimate the average requirement for
maximal retention during adolescence and for zero
balance during maturity.
• Results were in the range of 35 to 40 mmol/d for growth
and varied from 22 to 40 mmol/d for mature adults.
• Even the low ends of these ranges are substantially above
both typical intakes today and the 1989 RDAs
• All but two of the randomized, controlled trials (RCTs) in
adults showed that elevating calcium intake reduced or
halted age-related bone loss or reduced osteoporotic
fractures at one or another bony site, or both.
• In one of the trials failing to find a benefit of increased
calcium intake, the study consisted of only 77 healthy men
in whom the mean calcium intake of the control group was
1159 mg, already relatively high.
• In the other, the subjects were early postmenopausal
women, a group in whom bone loss is predominantly
related to estrogen withdrawal, not to nutrition.
• Six controlled trials used dairy products as the calcium
source, and all were positive
• Six of the randomized controlled trials in adults and children
used dairy products as the principal source of calcium.
• All showed significantly positive effects that were at least as
strong as the effects of calcium supplements.
• It is evident that milk and milk products are good sources of
the nutrients needed for bone development and maintenance.
• Many population groups, particularly adolescent and
older females and older adults, consume diets
containing significantly less calcium than
recommended.
• At all ages, males consume more calcium than
females, presumably because of their higher energy
intake.
•Data from the Continuing Survey of Food Intakes by Individuals
(CSFII) 1994–96 indicate that only 12% of females ages 12 to 19 and
32% of similar aged males are meeting 100% of the AI (Adequate
Intakes) for calcium.
•According to this same survey, only 16% of women ages 20 to 29
years, 14% of women ages 30 to 39 years, and 11.5% of women 40
to 49 years are meeting 100% of the AI for calcium.
•Although less than 15% of older adults are consuming 100% of the
calcium AI, more men than women are meeting calcium
recommendations.
• Approximately 15% of males aged 50 to 59, 13% of males aged
60 to 69, and 13% of males over 70 years consume 100% of the
calcium recommendations. In contrast, only 5% of women ages
50 to 59, 4% of women aged 60 to 69, and 4% of women ages 70
and older consume 100% of the calcium recommendation.
• The low dietary calcium intake of adolescents is of particular
concern because it coincides with a period of rapid skeletal
growth—a "window of opportunity" to maximize peak bone
mass and protect against future risk for osteoporosis.
• About 90% of females’ total body bone mineral
content is achieved by age 16.9 years, 95% by age
19.8 years, and 99% by age 26.2 years, depending
on the site measured.
• Consequently, the period for optimizing peak bone
mass by calcium rapidly declines after
adolescence.
FIGURE... Percentage of Individuals Meeting 100 Percent of the 1997 AIs for
Calcium by Gender and Age, Two-Day Average 1994–1996
• Not only are milk and other dairy foods calcium-dense foods
providing in many cases about 300 mg calcium per serving, but
these foods also contain other nutrients important to health.
• Milk and other dairy foods contain → vitamins D, A, and B12,
protein, potassium, riboflavin, niacin, and phosphorus.
• Vitamin D-fortified milk products provide dietary intake of
vitamin D → increases the absorption of calcium.
NUTRIENT 1997%
Energy 9.3
Protein 19.4
Fat 12.6
Carbohydrate 4.6
Minerals
Calcium 72.1
Phosphorus 32.4
Zinc 16.2
Magnesium 15.8
Iron 1.8
Vitamins
Riboflavin 26.1
Vitamin B 12 21.6
Vitamin A 15. 3
Vitamin B 6 8.7
Folate 6.2
Thiamin 4.7
Vitamin E 2.8
Ascorbic Acid 2.5
Niacin 1.2
• Because milk and other dairy foods are excellent sources of calcium as
well as many other essential nutrient, their intake improves the overall
nutritional quality of the diet.
• A longitudinal study involving 64 postmenopausal women in Australia
found that the women who were randomly assigned to receive 1,000
mg of additional calcium per day by consuming fat free milk powder
increased not only their calcium intake, but also their intake of other
essential nutrients such as protein, potassium, phosphorus, magnesium,
riboflavin, thiamin and zinc.
• Women who took calcium supplements (calcium lactate
gluconate) increased only their intake of calcium and
sodium.
• Although both milk powder and calcium supplements
increased calcium intake, consuming the fat free skim milk
powder improved the women’s total diet as well.
• The total nutrient content of milk is also well understood,
and it is almost unnecessary to state here that milk
products are richer sources of calcium, phosphorus,
magnesium, potassium, zinc and protein, per unit energy,
than the average of other typical foods in an adult diet.
• As a consequence, a diet devoid of dairy products will
often be a poor diet, not just in respect to calcium, but for
many other nutrients as well.
• Consuming calcium-rich foods is the preferred approach to achieving
optimal calcium intakes.
• Dairy foods: major source of calcium → other essential nutrients,
including vitamin D, which increases calcium absorption.
• Consuming dairy foods improves the overall nutritional quality of the
diet.
• Nondairy foods: salmon with bones, green leafy vegetables and
legumes also provide calcium.
• Calcium-fortified foods and calcium supplements: option for
individuals who cannot meet their calcium needs from foods naturally
containing this mineral.
• Their use does not correct the poor dietary patterns of food selection
which are the underlying cause low calcium consumption.
• Intake of calcium-fortified foods and calcium supplements may
increase the risk for calcium toxicity, especially among individuals
who already meet their calcium needs from foods naturally
containing this mineral.
1. Heaney RP. Calcium, Dairy Products and Osteoporosis. Journal of the American College of Nutrition 2000; 19: 83S-99S.
2. Heaney RP. Bone Health. American Journal of Clinical Nutrition 1997; 85: 300S-303S.
3. Miller GD, Jarvis JK, McBean LD. The Importance of Meeting Calcium Needs with Foods. Journal of the American College of Nutrition 2001; 20: 168S-185S
4. Yeap SS, Hosking DJ. Management of Corticosteroid - Induced Osteoporosis. Rheumatology 2002; 41: 1088–1094
5. Reid IR, Ames RW, Evans MC, Gamble GD, Sharpe SJ. Effect of Calcium Supplementation on Bone Loss in Postmenopausal Women. N Engl J Med 1993; 328: 460–464.
6. Cumming RG, Cummings SR, Nevitt MC, Scott J, Ensrud KE, Vogt TM, Fox K: Calcium Intake and Fracture Risk: Results from The Study of Osteoporotic Fractures. Am J Epidemiol 1997; 145: 926–934.
7. Chapuy MC, Arlot ME, Duboeuf F, et al. Vitamin D3 and Calcium to Prevent Hip Fractures in Elderly Women. N Engl J Med 1992; 327: 1637–42.
8. Suleiman S, Nelson M, Li F, Buxton-Thomas M, Moniz C: Effect of Calcium Intake and Physical Activity Level on Bone Mass and Turnover in Healthy, White, Postmenopausal Women. Am J Clin Nutr 1997; 66: 937–943.