Matti Nark
Mon, Mar-12-07, 17:17
The Dutch study
Wicherts IS, van Schoor NM, Boeke AJ, Visser M, Deeg DJ, Smit
J, Knol DL, Lips P. Vitamin D status predicts physical
performance and its decline in older persons. J Clin
Endocrinol Metab. 2007 Mar 6; [Epub ahead of print] PMID:
17341569 [PubMed - as supplied by publisher] <http://jcem.end-
ojournals.org/cgi/content/abstract/jc.2006-1525v1>
<http://jcem.endojournals.org/cgi/rapidpdf/jc.2006-1525v1>
(koko teksti PDF-tiedostona),
just published online, found that low vitamin D status is
common in older persons and associated with poorer physical
performance and a greater decline in physical performance.
Below the abstract of this study:
"Context: Vitamin D deficiency is common among older
people, and can cause mineralization defects, bone loss,
and muscle weakness. Objective: To investigate the
association of serum 25-hydroxyvitamin D (25-OHD)
concentration with current physical performance and its
decline over 3 years among elderly. Design:
Cross-sectional and longitudinal design (3 years
follow-up) within the Longitudinal Aging Study Amsterdam.
Setting: An age- and sex-stratified random sample of the
Dutch older population. Other participants: Subjects
included 1234 men and women (aged 65yr and older) for
cross- sectional analysis, and 979 (79%) persons for
longitudinal analysis. Main Outcome Measure(s): physical
performance (sum score of the walking test, chair stands,
and tandem stand) and decline in physical performance.
Results: serum 25-OHD was associated with physical
performance after adjustment for age, gender, chronic
diseases, degree of urbanization, BMI, and alcohol
consumption. Compared with individuals with serum 25-OHD
levels above 30ng/ml, physical performance was poorer in
participants with serum 25-OHD<10ng/ml (B= -1.69; 95%
confidence interval[CI]= -2.28; -1.10), and with serum
25-OHD 10-20ng/ml (B= -0.46; 95%CI=-0.90;-0.03). After
adjustment for confounding variables, participants with
25-OHD<10ng/ml and 25-OHD 10-20ng/ml had significantly
higher odds ratios (OR) for 3-year decline in physical
performance ([OR=2.21; 95%CI=1.00- 4.87] and [OR=2.01;
95%CI=1.06-3.81]), compared with participants with
25-OHD>/=30ng/ml. The results were consistent for each
individual performance test. Conclusions: Serum 25-OHD
concentrations <20ng/ml are associated with poorer
physical performance and a greater decline in physical
performance in older men and women. Because almost 50% of
the population had serum 25-OHD<20ng/ml, public health
strategies should be aimed at this group."
--
Matti Narkia
Matti Nark
Tue, Mar-13-07, 06:16
On Tue, 13 Mar 2007 00:18:17 +0200, Matti Narkia
<mna@mbnet.fi> wrote:
>On Mon, 12 Mar 2007 15:42:39 -0400, CliffMacgillivray
><nospam@fake-email.net> wrote:
>
>>Matti Narkia wrote:
>>> just published online, found that low vitamin D status is
>>> common in older persons and associated with poorer
>>> physical performance and a greater decline in physical
>>> performance. Below the abstract of this study:
>>
>>*gasp* So old people that are too frail to go outside into
>>the sunlight have low vitamin D levels!?!? I think that
>>being too frail to go outside leads to the vitamin D
>>deficiency and not the other way around.
>
>A good point, and because this was an epidemiological study,
>no causal conclusions can be drawn. Certainly not going out
>will lead to a low vitamin D status, if supplements are not
>used. Still, the study claims that the association of low
>vitamin D status with poorer physical performance and its
>greater decline remained significant after adjustment for
>number of chronic diseases and physical activity. From the
>discussion chapter of the study:
>
> "This study clearly shows that physical performance is
> not only associated with vitamin D status
> cross-sectionally, but that vitamin D status is also
> associated with decline over time in physical
> performance. Compared with the reference group (25-OHD >=
> 30 ng/ml), participants with levels up to 20 ng/ml had
> significantly lower scores for physical performance, and
> had higher odds for decline in physical performance. This
> was significant after adjustment for age, gender, number
> of chronic diseases, degree of urbanization, BMI, alcohol
> consumption, and physical activity."
References about the relation between vitamin D status and
muscle function and physical performance:
Gloth FM III, Smith CE, Hollis BW, Tobin JD. Functional
improvement with vitamin D replenishment in a cohort of frail,
vitamin D-deficient older people. J Am Geriatr Soc
1995;43:1269-71. <http://www.ncbi.nlm.nih.gov/entrez/query.fc-
gi?cmd=retrieve&db=pubmed&list_uids=7594162&dopt=Abstract>
"CONCLUSIONS: In this cohort of homebound older people,
improvement in vitamin D status was associated with
functional improvement as measured by the FEFA
questionnaire."
Verhaar HJ, Samson MM, Jansen PA, de Vreede PL, Manten JW,
Duursma SA. Muscle strength, functional mobility and vitamin D
in older women. Aging (Milano). 2000 Dec;12(6):455-60. PMID:
11211956 [PubMed - indexed for MEDLINE] <http://www.ncbi.nlm.-
nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=Abstrac-
tPlus&list_uids=11211956>
"Six months of treatment with alphacalcidol led to
significant improvements (compared to the controls)
in values of isometric knee extensor strength (left
leg: 14.6% +/-
5.7%. p=0.03; right leg: 11.5% +/- 5.0%, p=0.02) (mean +/-
SEM). The achievements in the timed "Up & Go" test and
2- minute walking test did not improve in the
alphacalcidol group compared to the controls after 6
months. However, within the vitamin D-deficient group, 6
months of alphacalcidol treatment led to a significant
increase in the walking distance over 2 minutes
(increase from 137.6 +/- 12.6 to 151.3 +/- 11.2 meters,
p=0.03). The controls, with normal vitamin D levels, did
not exhibit improvements in performance of any of the
tests over a period of 6 months. Summarized,
alphacalcidol seems to improve muscle strength and
walking distance over 2 minutes in vitamin D-deficient
older women."
Ziambaras K, Dagogo-Jack S. Reversible muscle weakness in
patients with vitamin D deficiency. West J Med 1997;167:435?9.
<http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pub-
med&pubmedid=9426489> <http://www.pubmedcentral.nih.gov/picre-
nder.fcgi?artid=1304730&blobtype=pdf>
"We report on two patients who presented with significant
proximal muscle weakness, one with vitamin D malabsorption
and one with dietary vitamin D deficiency. A search for
inflammation or other causes of myopathy was negative.
Muscle biopsy in one patient revealed type IIB fiber
atrophy. Once normal serum 25-hydroxyvitamin D3 levels
were restored, both patients experienced gradual muscle
strength improvement and reversal of proximal myopathy
within 6 months.
[...]
The ultimate proof of the diagnosis of vitamin D-deficient
muscle weakness rests on the response to therapy.
Improvement in muscle strength has been observed as early
as after a week,5 but usually within one to two
months,14,15 of treatment with pharmacologic doses of
vitamin D. Treatment is required for several months,
however, for complete recovery of muscle strength.13,15"
Glerup H, Mikkelsen K, Poulsen L, et al. Hypovitaminosis D
myopathy without biochemical signs of osteomalacic bone
involvement. Calcif Tissue Int 2000;66:419?24. <http://www.nc-
bi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db=pubmed&list_-
uids=10821877&dopt=Abstract>
"Hypovitaminosis D myopathy is a prominent symptom of
vitamin D deficiency, and severely impaired muscle
function may be present even before biochemical signs of
bone disease develop. Full normalization of
hypovitaminosis D myopathy demands high-dose vitamin D
treatment for 6 months or more. Our findings indicate that
serum levels of ALP cannot be used in the screening for
hypovitaminosis D myopathy. Assessment of s-25OHD is the
only reliable test."
Prabhala A, Garg R, Dandona P. Severe myopathy associated with
vitamin D deficiency in western New York. Arch Intern Med
2000; 160:1199-203 <http://archinte.ama-assn.org/cgi/content/-
abstract/160/8/1199>
"Five cases of severe myopathy associated with vitamin D
deficiency are described. Each patient was confined to a
wheelchair because of weakness and immobility. Two were
elderly, 1 was a 37-year-old African American with type 1
diabetes mellitus, 1 was being treated for carcinoid
syndrome, and 1 was severely malnourished due to poor oral
intake. In each, weakness had previously been attributed
to other causes, including old age, concomitant diabetic
neuropathy, or general debility. Correct diagnosis was
made initially by a high index of suspicion, following the
demonstration of clinical proximal myopathy; confirmation
was made by the demonstration of low 25-hydroxyvitamin D
and elevated parathyroid hormone concentrations. Treatment
with vitamin D caused a resolution of body aches and pains
and a restoration of normal muscle strength in 4 to 6
weeks. Four patients became fully mobile and had normal
25-hydroxyvitamin D concentrations, and the fifth also
became mobile. In the 4 fully recovered cases, parathyroid
hormone levels on follow- up were lower but still
elevated. This finding suggests a degree of autonomy of
parathyroid secretion known to occur in cases of
long-standing vitamin D deficiency. Myopathy, due to
chronic vitamin D deficiency, probably contributes to
immobility and ill health in a significant number of
patients in the northern United States. An awareness of
this condition may significantly improve mobility and
quality of life in patient populations vulnerable to
vitamin D deficiency."
Endo I, Inoue D, Mitsui T, Umaki Y, Akaike M, Yoshizawa T,
Kato S, Matsumoto T. Deletion of vitamin D receptor gene in
mice results in abnormal skeletal muscle development with
deregulated expression of myoregulatory transcription factors.
Endocrinology. 2003 Dec;144(12):5138-44. Epub 2003 Aug 13.
PMID: 12959989 [PubMed - indexed for MEDLINE]
<http://endo.endojournals.org/cgi/content/full/144/12/5138>
"These results suggest that VDR plays a physiological role
in skeletal muscle development, participating in
temporally strict down-regulation of myoregulatory
transcription factors. The present study can form a
molecular basis of VDR actions on muscle and should help
further establish the physiological roles of VDR in muscle
development as well as pharmacological effects of vitamin
D on muscle functions."
Pfeifer M, Begerow B, Minne HW. Vitamin D and muscle function.
Osteoporos Int. 2002 Mar;13(3):187-94. Review. PMID: 11991436
[PubMed - indexed for MEDLINE] DOI: 10.1007/s001980200012 <ht-
tp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Ret-
rieve&dopt=AbstractPlus&list_uids=11991436>
Staud R. Vitamin D: more than just affecting calcium and bone.
Curr Rheumatol Rep. 2005 Oct;7(5):356-64. Review. PMID:
16174483 [PubMed - indexed for MEDLINE] <http://www.ncbi.nlm.-
nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=Abstrac-
tPlus&list_uids=16174483>
"Clinical consequences related to low vitamin D levels
include not only osteomalacia, osteoporosis, and rickets,
but also neuro-muscular dysfunction and fractures. Falls
related to neuromuscular dysfunction lead to 40% of all
nursing home admissions and are the largest single cause
of injury-related deaths in elderly people.
[...]
It is well established that vitamin D deficiency not only
has serious consequences for bone health, but also for
other organ systems. Previous studies have shown that
vitamin D supplementation reduces the number of fractures
and directly improves neuromuscular function, thus helping
to prevent falls and subsequent fractures."
Boonen S, Bischoff-Ferrari HA, Cooper C, Lips P, Ljunggren O,
Meunier PJ, Reginster JY. Addressing the musculoskeletal
components of fracture risk with calcium and vitamin D: a
review of the evidence. Calcif Tissue Int. 2006
May;78(5):257-70. Epub 2006 Apr 21. Review. PMID: 16622587
[PubMed - indexed for MEDLINE] <http://www.ncbi.nlm.nih.gov/e-
ntrez/query.fcgi?itool=abstractplus&db=pubmed&cmd=Retrieve&do-
pt=abstractplus&list_uids=16622587>
<http://www.springerlink.com/content/w786x2mjm3276ggk/>
"Additionally, calcium and vitamin D supplementation
significantly improves body sway and lower extremity
strength, reducing the risk of falls."
Zittermann A. Vitamin D in preventive medicine: are we
ignoring the evidence? Br J Nutr. 2003 May;89(5):552-72.
Review. PMID: 12720576 [PubMed - indexed for MEDLINE]
<http://tinyurl.com/249efc> (full text available from
that page)
"It has been assumed already at the beginning of the 20th
century that severe vitamin D deficiency results in a
disturbed muscle metabolism (Ritz et al. 1980). Animal
studies have demonstrated that the aktinomyosin content of
myofibrills is reduced during experimental rickets
(Stroder & Arensmeyer, 1965). Moreover, vitamin D
deficiency can impair intracellular Ca metabolism in
muscle cells. The Ca content of mitochondria isolated from
vitamin D-depleted chicks is low (Pleasure et al. 1979)
and Ca uptake into the sarcoplasmic reticulum is reduced
during vitamin D deficiency (Curry et al. 1983). Patients
with osteomalacia suffer from muscle weakness and have low
serum levels of muscle enzymes (Ritz et al. 1980; Rimaniol
et al. 1994). Supplementation with 357 or 1250 mcg vitamin
D/d or 50 mcg 25(OH)D/d for 1 to 2 months was able to
normalize muscle strength in patients with myopathy
(Rimaniol et al. 1994; Ziambaras & Dagogo-Jack,
6). Sub-clinical myopathy may even occur at serum
25(OH)D levels of 10-50 nmol/l (Peacock, 1995). In
line with this assumption, leg extension power was
positively correlated with serum 25(OH)D levels in
elderly males and with serum calcitriol levels in the
whole group of males and females. The males had mean
25(OH)D levels of 90 (sd 87.5) nmol/l and the females
had mean 25(OH)D levels of 68 (sd 53) nmol/l
(Bischoff et al. 1999b) indicating that a large
number of subjects had an insufficient vitamin D
status. A recent study has brought forward evidence
that a low vitamin D status also contributes to the
pathogenesis of congestive heart failure, a disease
resulting in cardiac muscle weakness due to impaired
myocardial contractility. Circulating levels of NT-
proANP, a biochemical indicator of congestive heart
failure severity, were inversely correlated with
serum 25(OH)D levels (r2 0.16, P>0.001; Zittermann et
al. 2003).
Supplemental studies have demonstrated that doses of 0.5
mcg calitriol/d or 10 mcg vitamin D/d had no effects on
parameters of muscle function (Table 4). A daily
supplement of very high doses of vitamin D and also doses
of 20 mcg vitamin D/d could, however, significantly
improve muscle function in subjects with low initial
25(OH)D levels (Table 4). It should also be mentioned that
in both intervention trials the 20 mcg vitamin
D/d was combined with a daily supplement of 1 200 mg Ca.
Probably, the combined effect of 20 mcg vitamin D with
high doses of oral Ca was responsible for the beneficial
effects in these studies."
Mowe M, Haug E, Bohmer T. Low serum calcidiol concentration in
older adults with reduced muscular function. J Am Geriatr Soc
1999;47:220-6. <http://www.ncbi.nlm.nih.gov/entrez/query.fcgi-
?cmd=retrieve&db=pubmed&list_uids=9988294&dopt=Abstract>
"CONCLUSIONS: Older people with reduced muscle function
often had reduced levels of calcidiol serum concentration.
Low levels of calcidiol were not associated with signs of
general undernutrition, such as low body mass, or with
reduced arm- muscle circumference or triceps skinfold
thickness. This finding may suggest a physiological role
for calcidiol in muscle function. Reduced muscle strength
increased disability in our older subjects, which may be
improved by vitamin D supplementation in vitamin
D-deficient subjects.
[...]
Our findings may be clinically relevant to the
musculoskeletal health in the aged, because vitamin D
insufficiency has been shown to be associated with lower
muscle strength and increased falling tendency in adults.
Conversely, supplement of native vitamin D or treatment
with active vitamin D has been reported to improve muscle
functions and protect from falling events and falling-
associated fractures (29, 30, 31, 32, 33). Whether the
beneficial effects of vitamin D treatment occur via direct
VDR actions on skeletal muscle cells or indirect
mechanisms remains unclear. Interestingly, however,
abnormal expression of MyoD family members and MHC
isoforms has been reported in various models of
immobilization and denervation (34, 35, 36, 37, 38).
Considering the plasticity and highly adaptive nature of
muscle fibers, it is conceivable that reprogramming and
adaptations of muscle fibers may occur under various
pathological conditions, particularly in elderly patients,
and that these processes may be modulated by VDR-dependent
vitamin D actions.
In summary, we have shown that VDR gene deleted mice
exhibit abnormal skeletal muscle development. These
abnormalities occur independently of secondary metabolic
changes such as hypocalcemia and hypophosphatemia and are
accompanied by deregulated expression of myogenic
transcription factors and MHC isoforms. These effects
appear to involve direct vitamin D actions on muscle
through VDR, because similar effects were reproduced by
treatment of VDR-positive myoblastic cells with 1,25(OH)2D
in vitro. The present study can form a molecular basis of
VDR actions on muscle and should help further establish
the physiological roles of VDR in muscle development as
well as pharmacological effects of vitamin D on muscle
functions."
Solomon AM, Bouloux PM. Modifying muscle mass - the endocrine
perspective. J Endocrinol. 2006 Nov;191(2):349-60. Review.
PMID: 17088404 [PubMed - indexed for MEDLINE] <http://joe.end-
ocrinology-journals.org/cgi/content/full/191/2/349>
"Calcium, vitamin D and phosphate levels all impact on
muscle function most notably in deficiency states such as
the myopathy seen in osteomalacia. This has been confirmed
as a histological atrophy of muscle, predominantly type II
fibres and is exacerbated by ageing (Janssen et al. 2002).
Polymorphisms of the vitamin D receptor and vitamin D
knockout models have a significant muscle phenotype (Demay
2003). Vitamin D null mice have smaller muscle fibres and
raised levels of MRFs. These changes are reversed by
treatment with vitamin D (Endo et al. 2003). Vitamin
D- receptor polymorphisms associated with body
composition and muscle strength have been reported in
men and women. One study assessing older men showed
variation in the vitamin D- receptor FokI
polymorphism (Roth et al. 2004), with a different
polymorphism linked with muscle strength in a further
study of older women (Geusens et al. 1997). In a
longitudinal study looking at sarcopenia in older men
and women, low vitamin D was linked with increased
risk (by approximately x2) of reduced muscle mass and
strength. a similar relationship was found with
raised parathyroid hormone levels (Visser et al.
2003). In functional terms, several trials have
examined the relationship between vitamin D status
and falls; these have been recently reviewed
(Mosekilde 2005)."
Janssen HCJP, Samson MM, Verhaar HJJ. Vitamin D deficiency,
muscle function, and falls in elderly people. Am J Clin Nutr
2002;75:611-5. <http://www.ajcn.org/cgi/content/full/80/2/496>
"In conclusion, vitamin D deficiency is a condition that
may cause muscle weakness in elderly persons. Although
only a few intervention studies with vitamin D have been
conducted in elderly people, the available evidence
indicates that vitamin D supplementation preserves muscle
strength and functional ability in high-risk groups, eg,
frail, mostly homebound elderly people. Additional
research, preferably by means of controlled randomized
trials, is needed to confirm these findings."
Visser M, Deeg DJ, Lips P. Low vitamin D and high parathyroid
hormone levels as determinants of loss of muscle strength and
muscle mass (sarcopenia): the Longitudinal Aging Study
Amsterdam. J Clin Endocrinol Metab 2003;88:5766?72. <http://j-
cem.endojournals.org/cgi/content/abstract/88/12/5766>
"After adjustment for physical activity level, season of
data collection, serum creatinine concentration, chronic
disease, smoking, and body mass index, persons with low
(<25 nmol/liter) baseline 25-OHD levels were 2.57 (95%
confidence interval 1.40-4.70, based on grip strength) and
2.14 (.73-6.33, based on muscle mass) times more likely to
experience sarcopenia, compared with those with high (>50
nmol/liter) levels. High PTH levels (>=4.0 pmol/liter)
were associated with an increased risk of sarcopenia,
compared with low PTH (<3.0 pmol/liter): odds ratio = 1.71
(1.07-2.73) based on grip strength, odds ratio = 2.35
(1.05-5.28) based on muscle mass. The associations were
similar in men and women. The results of this prospective,
population-based study show that lower 25-OHD and higher
PTH levels increase the risk of sarcopenia in older men
and women."
Bishoff HA, Stahelin HB, Urscheler N, et al. Muscle strength
in the elderly: its relation to vitamin D metabolites. Arch
Phys Med Rehabil 1999;80:54?8. <http://www.ncbi.nlm.nih.gov/e-
ntrez/query.fcgi?cmd=retrieve&db=pubmed&list_uids=9915372&dop-
t=Abstract>
"CONCLUSION: Muscle strength declined with age in
ambulatory elderly people and showed modest, but
significant, positive correlation with 1,25(OH)2 vitamin D
in both sexes and with 25(OH)D in male subjects. Therefore
vitamin D deficiency appears to contribute to the
age-related loss of muscle strength, which might be more
pronounced in institutionalized elderly people with a high
prevalence of vitamin D deficiency."
Bischoff-Ferrari HA, Dietrich T, Orav EJ, Hu FB, Zhang Y,
Karlson EW, Dawson-Hughes B. Higher 25-hydroxyvitamin D
concentrations are associated with better lower-extremity
function in both active and inactive persons aged > or
=60 y.
Am J Clin Nutr. 2004 Sep;80(3):752-8. PMID: 15321818 [PubMed -
indexed for MEDLINE]
<http://www.ajcn.org/cgi/content/full/80/3/752>
"BACKGROUND: Vitamin D may improve muscle strength through
a highly specific nuclear receptor in muscle tissue.
[...]
CONCLUSION: In both active and inactive ambulatory
persons aged > or =60 y, 25(OH)D concentrations between
40 and 94 nmol/L are associated with better
musculoskeletal function in the lower extremities than
are concentrations < 40 nmol/L."
Szulc P, Duboeuf F, Marchand F, Delmas PD. Hormonal and
lifestyle determinants of appendicular skeletal muscle mass in
men: the MINOS study. Am J Clin Nutr. 2004 Aug;80(2):496-503.
PMID: 15277176 [PubMed - indexed for MEDLINE]
<http://www.ajcn.org/cgi/content/full/80/2/496>
"CONCLUSION: In elderly men, low physical activity,
tobacco smoking, thinness, low testosterone (AFTC and
FTI), and decreased 25(OH)D concentrations are risk
factors for sarcopenia."
Zamboni M, Zoico E, Tosoni P, et al. Relation between vitamin
D, physical performance, and disability in elderly persons. J
Gerontol A Biol Sci Med Sci 2002;57:M7?11 <http://biomed.gero-
ntologyjournals.org/cgi/content/abstract/57/1/M7>
"Conclusions. In community-dwelling elderly women, 25(OH)D
is related to muscular function and reported disability.
Because of the high prevalence of hypovitaminosis D in the
elderly population, this association seems to be
clinically relevant."
J. R Sharkey, C. Giuliani, P. S Haines, L. G Branch, J.
Busby-Whitehead, and N. Zohoori Summary measure of dietary
musculoskeletal nutrient (calcium, vitamin D, magnesium,
and phosphorus) intakes is associated with lower-extremity
physical performance in homebound elderly men and women Am.
J. Clinical Nutrition, April 1, 2003; 77(4): 847 - 856.
<http://www.ajcn.org/cgi/content/full/77/4/847>
See also the link
<http://heartscanblog.blogspot.com/search?q=vitamin+d>
provided by RArmant for the references aboty the relation
between vitamin D status and physical performance.
--
Matti Narkia
Matti Nark
Tue, Mar-13-07, 17:16
On Tue, 13 Mar 2007 12:34:45 +0200, Matti Narkia
<mna@mbnet.fi> wrote:
>On Tue, 13 Mar 2007 00:18:17 +0200, Matti Narkia
><mna@mbnet.fi> wrote:
>
>>On Mon, 12 Mar 2007 15:42:39 -0400, CliffMacgillivray
>><nospam@fake-email.net> wrote:
>>
>>>Matti Narkia wrote:
>>>> just published online, found that low vitamin D status is
>>>> common in older persons and associated with poorer
>>>> physical performance and a greater decline in physical
>>>> performance. Below the abstract of this study:
>>>
>>>*gasp* So old people that are too frail to go outside into
>>>the sunlight have low vitamin D levels!?!? I think that
>>>being too frail to go outside leads to the vitamin D
>>>deficiency and not the other way around.
>>
>>A good point, and because this was an epidemiological study,
>>no causal conclusions can be drawn. Certainly not going out
>>will lead to a low vitamin D status, if supplements are not
>>used. Still, the study claims that the association of low
>>vitamin D status with poorer physical performance and its
>>greater decline remained significant after adjustment for
>>number of chronic diseases and physical activity. From the
>>discussion chapter of the study:
>>
>> "This study clearly shows that physical performance is
>> not only associated with vitamin D status
>> cross-sectionally, but that vitamin D status is also
>> associated with decline over time in physical
>> performance. Compared with the reference group (25-OHD
>> >= 30 ng/ml), participants with levels up to 20 ng/ml
>> had significantly lower scores for physical performance,
>> and had higher odds for decline in physical performance.
>> This was significant after adjustment for age, gender,
>> number of chronic diseases, degree of urbanization, BMI,
>> alcohol consumption, and physical activity."
>
>References about the relation between vitamin D status and
>muscle function and physical performance:
>
See also
Vitamin D Micronutrient Information Center - Linus Pauling
Institute
<http://lpi.oregonstate.edu/infocenter/vitamins/vitaminD/>
"Vitamin D deficiency causes muscle weakness and pain in
children and adults. Muscle pain and weakness was a
prominent symptom of vitamin D deficiency in a study of
Arab and Danish Moslem women living in Denmark (20). In a
cross-sectional study of 150 consecutive patients referred
to a clinic in Minnesota for the evaluation of persistent,
nonspecific musculoskeletal pain, 93% had serum 25(OH)D
levels indicative of vitamin D deficiency (21). A
randomized controlled trial found that supplementation of
elderly women with 800 IU/day of vitamin D and 1,200
mg/day of calcium for three months increased muscle
strength and decreased the risk of falling by almost 50%
compared to supplementation with calcium alone
(22)."
References mentioned in above excerpt:
23. Bringhurst FR, Demay MB, Kronenberg HM. Mineral
Metabolism. In: Larson PR, Kronenberg HM, Melmed S,
Polonsky KS, eds. Larsen: Williams Textbook of
Endocrinology: Elsevier; 2003:1317-1320.
24. Plotnikoff GA, Quigley JM. Prevalence of severe
hypovitaminosis D in patients with persistent,
nonspecific musculoskeletal pain. Mayo Clin Proc.
2003;78(12):1463-1470. <http://www.ncbi.nlm.nih.gov/entr-
ez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14661675&-
dopt=Abstract>
25. Bischoff HA, Stahelin HB, Dick W, et al. Effects of
vitamin D and calcium supplementation on falls: a
randomized controlled trial. J Bone Miner Res.
2003;18(2):343-351. <http://www.ncbi.nlm.nih.gov/entrez/-
query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12568412&dop-
t=Abstract>
"Musculoskeletal function improved significantly in the
Cal+D-group (p = 0.0094). A single intervention with
vitamin D plus calcium over a 3-month period reduced the
risk of falling by 49% compared with calcium alone. Over
this short- term intervention, recurrent fallers seem to
benefit most by the treatment. The impact of vitamin D on
falls might be explained by the observed improvement in
musculoskeletal function."
--
Matti Narkia