Transcript Why vitamin D is important - An

Why Vitamin D is important for Bone health?
Basel Masri, MD
Consultant Rheumatologist
Jordan Osteoporosis Center
Jordan Hospital
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Jordanian Osteoporosis Prevention Society
Al-Najah University
9 October 2009
Nablus - Palestine
Vitamin D
fat soluble prohormone
necessary for bone health, it controls
absorption of calcium from the intestines
and its use in bone mineralization
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two important representatives:
Vitamin D2 found in plants considerably less potent than
Vitamin D3 naturally occurring form in humans
Sources of Vitamin D (1)
Known as the Sunshine Vitamin
Sunlight Exposure provides 90% of vitamin
D for the body’s daily requirement
Vitamin D production is affected by:
 season
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 duration and body-surface of exposure
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 sunscreen use
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 and skin pigmentation
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*Sold in the United States, Canada, Argentina (optional), Brazil, Guatemala, Honduras, Mexico, Philippines (optional), and Venezuela
Adapted from Holick MF; Allain TJ, Dhesi J; Webb AR et al; Reid IR et al; Matsuoka LY et al; Holick MF; Lips P; Macleod CC et al;
Omdahl JL et al; Chen TC et al; Holick MF et al; Heaney RP; Segal E et al; Webb AR et al; Faulkner H et al; Roche Vitamins Europe Ltd.
Sources of Vitamin D (2)
Endogenous production
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Ability of skin, liver and
kidneys to form and process
vitamin D
*Sold in the United States, Canada, Argentina (optional), Brazil, Guatemala, Honduras, Mexico, Philippines (optional), and Venezuela
Adapted from Holick MF; Allain TJ, Dhesi J; Webb AR et al; Reid IR et al; Matsuoka LY et al; Holick MF; Lips P; Macleod CC et al;
Omdahl JL et al; Chen TC et al; Holick MF et al; Heaney RP; Segal E et al; Webb AR et al; Faulkner H et al; Roche Vitamins Europe Ltd.
Sources of Vitamin D (3)
Dietary intake 10% only
Minor source of vitamin D, providing 100 IU/day
Vitamin D is rare in foods other than fatty fish, eggs,
and supplemented dairy products*
Even vitamin D–fortified dairy products may not
contain level indicated on label
Vitamin D can be supplied by multivitamins and
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O Supplements containing vitamin D alone are not readily
available
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Patient compliance with supplementation therapy is
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*Sold in the United States, Canada, Argentina (optional), Brazil, Guatemala, Honduras, Mexico, Philippines (optional), and Venezuela
Adapted from Holick MF; Allain TJ, Dhesi J; Webb AR et al; Reid IR et al; Matsuoka LY et al; Holick MF; Lips P; Macleod CC et al;
Omdahl JL et al; Chen TC et al; Holick MF et al; Heaney RP; Segal E et al; Webb AR et al; Faulkner H et al; Roche Vitamins Europe Ltd.
Diseases and Conditions
that Vitamin D Helps Prevention
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Rickets
Osteomalacia
Osteoporosis
Hyperparathyroism
Internal cancers
Multiple sclerosis
Other Diseases that UVB /
Vitamin D Helps Prevention
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Muscle pain, weakness
Progression of rheumatoid and osteo-arthritis
Type 1 diabetes mellitus in infancy
Type 2 diabetes mellitus
Body, brain disorders during fetal development
Irritable bowel syndrome, Crohn’s disease
High blood pressure, heart disease
Tuberculosis
Reasons for High Prevalence of Vitamin D
Inadequacy in Postmenopausal Women
Lack of sunlight exposure
Poor nutrition
Less efficient synthesis of vitamin D in the skin
Lower amount of vitamin D precursor 7J
O dehydrocholesterol in the skin
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Adapted from Allain TJ, Dhesi J Gerontology 2003;49:273–278; Holick MF Am J Clin Nutr 1994;60:619–630; Lips P. In: Advances in Nutritional
Research, Vol 9. New York: Plenum Press, 1994:151–165; Webb AR et al Am J Clin Nutr 1990;51:1075–1081; Holick MF et al Lancet 1989;2:
1104–1105; MacLaughlin J, Holick MF J Clin Invest 1985;76:1536–1538.
Levels of Serum 25(OH)D
Deficiency is <10 ng/ml (25 nmol/L)
 Insufficiency is between 10 and 30 ng/ml
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(25-75 nmol/L)
Below 16 ng/ml (40 nmol/L), circulating
1,25(OH)D levels fall
 For bone health and other conditions,
optimal level is up to 36 ng/ml (90 nmol/L);
40 ng/ml (100 nmol/L) for those over the age
of 70 years
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How Much Vitamin D is Required?
Present-day guidelines:
400 I.U./day for young & middle-aged persons
600 I.U./day for those around 50-70 years of age
and 800 I.U. for those over the age of 70 years
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These guidelines were developed a
number of years ago and are based on
developing and maintaining strong bones
How Much Solar UVB Exposure?
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Michael Holick, MD, PhD, Boston
University, author of The UV Advantage, now
estimates that one needs to expose 25% of
the body to midday solar radiation, 2-3
times a week, during summer, to produce the
amount of vitamin D considered optimal
This is for light-skinned individuals;
darker skinned ones need more exposure
Consequences of Subclinical
Vitamin D Inadequacy
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•  Calcium absorption
•  PTH
•  Bone mineral density
Adapted from Parfitt AM et al Am J Clin Nutr 1982;36:1014–1031; Allain TJ, Dhesi J Gerontology 2003;49:273-278; Holick MF Osteoporos
Int 1998;8(suppl 2):S24–S29; DeLuca HF Metabolism 1990;39(suppl 1):3–9.
Why Vitamin D is important for
Osteoporosis Assessment
Epidemiological studies showed worldwide
inadequacy in Vitamin D particularly in
postmenopausal women
FiJoNOR survey
Others surveys
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patients insufficient in Vitamin D show lower
improvement with anti-resorptives drugs like
bisphosphonates
Evidence suggests that vitamin D inadequacy
increases risk of fracture
PTH=parathyroid hormone
Adapted from Parfitt AM et al Am J Clin Nutr 1982;36:1014–1031; Allain TJ, Dhesi J Gerontology 2003;49:273–278; LeBoff MS et al JAMA
1999;281:1505–1511; Bettica P et al Osteoporos Int 1999;9:226–229; Lips P et al J Clin Endocrinol Metab 2001;86:1212–1221; van der Wielen
RPJ et al Lancet 1995;346:207–210.
First Jordanian National
Osteoporosis Record
FiJoNOR
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Vitamin D Data
FiJoNOR
B. Masri, E. Azar, A. Faqih (JOPS)
FiJoNOR Population Distribution
Total of 821 randomized females
Mean age of menopause (48.5)
Number of women
Distribution of female population
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FiJoNOR
200
160
175
157
153
135
120
97
72
80
32
40
0
20-29
30-39
40-49
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50-59
60-69
70-79
80-89
Vitamin D levels in entire sample
450
413
400
273
300
33.5%
50.3%
16.2%
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< 10ng/ml
10-20 ng/ml
> 20 ng/ml
250
200
150
100
50
0
3
Deficiency
FiJoNOR
2
Insufficiency
B. Masri, E. Azar, A. Faqih (JOPS)
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Normal
No. of women
350
Vit. D (ng/ml)
Vit. D Covered (760) vs non-covered (61)
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20.00
18.00
16.00
14.00
12.00
10.00
8.00
6.00
4.00
2.00
0.00
18.95
13.02
Not Covered
FiJoNOR
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Covered
Vit. D vs Socioeconomic status
14.69
Vit. D (ng/ml)
15.00
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14.00
13.27
13.42
1
2
13.00
12.00
11.00
10.00
Low
FiJoNOR
Medium
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3
High
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Prevalence, % (± 95% CI)
Prevalence of Vitamin D Inadequacy
in Postmenopausal Women Treated
for Osteoporosis in North America
60
52.0%
N=1536
50
35.5%
40
30
18.2%
20
8.1%
10
0
1.1%
<9
<15
<20
<25
<30
Cutoff points for 25(OH)D concentration (ng/ml)
CI=confidence interval
Adapted from Holick MF et al J Clin Endocrinol Metab 2005;90:3215–3224.
Prevalence of Vitamin D Inadequacy (<30
ng/ml), by Age Group, in Postmenopausal
Women Treated for Osteoporosis
In an epidemiologic study conducted in North America (N=1536)
A high prevalence of vitamin D inadequacy was seen across all age groups
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Prevalence (%)
80
60
73.3%
(n=15)
N=1536
50.7%
(n=229)
48.0%
(n=488)
51–60
61–70
53.0%
(n=558)
57.6%
(n=245)
40
20
0
71–80
81–90
Age category
p=0.015 for test of trend
Adapted from Holick MF et al. Poster presented at ASBMR, October 1–5, 2004, Seattle, WA, USA.
>90
Prevalence of Vitamin D Inadequacy
(<30 ng/ml), by Region, in Postmenopausal
Women with Osteoporosis
In a cross-sectional observational international study
A high prevalence of vitamin D inadequacy was seen across all geographic
regions
90
81.8%
N=2589
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Prevalence (%)
80
70
71.4%
63.9%
60.3%
60
53.4%
57.7%
50
40
30
20
10
0
All
Australia
Latin
America
Asia
Middle
East
Regions
Adapted from Lips P et al. Poster presented at ASBMR, September 23–27, 2005, Nashville, TN, USA.
Europe
Vitamin D Supplementation
Decreases Fracture Risk
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The neglected role of „Muscle“ in the pathogenesis of
Osteoporosis
Muscle
Bone Density
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Falls
Osteoporosis
(Immobil.-induced Opo.)
Fracture
Active Vitamin D reduces the risk of osteoporotic fractures by a
dual effect
+
Vitamin D
Muscle
+
Bone Density
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Falls
Osteoporosis
Fractures
In a clinical study
Vitamin D Supplementation Decreases
Fracture Risk
Five-year randomized,
N=2686
Age 65–85 years
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Vitamin D = 100,000 IU
once every four months
(equivalent to 800 IU/day)
Men and women living
in the community
Adapted from Trivedi D et al BMJ 2003;326:469.
Fracture relative risk
(hip, wrist, forearm, spine)
double-blind, controlled trial
1.2
p=0.02
1.0
–33%
0.8
0.6
0.4
0.2
0.0
Untreated
(n=1341)
Treated
(n=1345)
Effect of Vitamin D and Calcium
Supplementation on Risk of Falling
Adapted from Bischoff HA et al J Bone Miner Res 2003;18:343–351.
Reduction in falls
1.2
p=0.01
1.0
0.8
Fall risk
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122 women
Age: 63–99 years
Randomized, double-blind,
controlled trial:
Calcium 1200 mg/day
Calcium 1200 mg/day
+ vitamin D 800 IU/day
12-week duration
Mean serum 25(OH)D
12 ng/ml at baseline
Women living in long-term
care units
–49%
0.6
0.4
0.2
0.0
Calcium
only
(n=44)
Calcium +
vitamin D
(n=45)
Summary I
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Vitamin D inadequacy is widespread in
postmenopausal women
Postmenopausal women have difficulty getting
enough Vitamin D:
 Formation and processing of vitamin D may
be impaired
 Exposure to sunlight may be limited
 Dietary sources provide little vitamin D
 Patient compliance with vitamin D
supplementation is inconsistent
Summary II
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Vitamin D is essential for calcium
absorption. Adequate calcium absorption
prevents secondary hyperparathyroidism and
limits bone resorption
Vitamin D supplementation has been
shown to reduce the risk of fracture and falls
and improves lower extremity function in the
elderly
Vitamin optimize antiresorptive drugs
efficacy specially Bisphosphonates