Author’s response to reviews
Title: Vitamin D Status in Non-Supplemented Postmenopausal Taiwanese Women with
Osteoporosis and Fragility Fracture
Authors:
Jawl-Shan Hwang (hwangjs@adm.cgmh.org.tw)
Keh-Sung Tsai (kstsaimd1128@ntuh.gov.tw)
Yuh-Min Cheng (k71058@kmhk.kmu.edu.tw)
Wen-Jer Chen (chenwenj@adm.cgmh.org.tw)
Shih-Te Tu (10836@cch.org.tw)
Ko-Hsiu Lu (cshy307@csh.org.tw)
Sheng-Mou Hou (shengmou@ms.skh.org.tw)
Shu-Hua Yang (shuhuayang@ntu.edu.tw)
Henrich Cheng (hc_cheng@vghtpe.gov.tw)
Hung Jen Lai (lai_jen@merck.com)
Sharon Lei (sharon_lei@merck.com)
Jung-Fu Chen (chenjf56090@gmail.com)
Version: 4 Date:25 May 2014
Author’s response to reviews: see over
1
The Biomed Central Editorial Team
BMC Musculoskeletal Disorders MS: 9915802121197507 - Vitamin D Status in
Postmenopausal Taiwanese Women with Osteoporosis and Fragility Fracture.
Thank you for consideration of our manuscript for publication in your journal.
We have reviewed the above manuscript according to your reviewer’s comments.
Reviewer #1 (Sami KOLTA)
Reviewer's report:
This is a paper dealing with vitamin D status in postmenopausal women with osteoporosis
and hip and vertebral fragility fractures.
The main limitation of this study (that has been pointed out by the authors) is that there
was not a healthy control group.
Specific comments:
- Patients and Methods section, Study design part:
1. Please delete the sentence "This is an observational study without administration of
any therapeutic or prophylactic agent under the protocol. The study determined the levels
of serum 25(OH)D in postmenopausal women under fragility fractures of the hip or
vertebrae."

Done, the sentence have deleted from page 6, line 12.
2. Please change the place of the last sentence "Among hip fractures patients, only
those ....and September1, 2011." To be just after the first sentence: "This multi-center,
cross-sectional, observational study was conducted in 8 medical centers in Taiwan.
Among hip fracture patients, ....".

Done, the sentence have changed on page 6 line 6.
- Patients and Methods section, Study Subjects part:
3. "Low-trauma fracture was defined as non-pathological fragility fracture of the hip or
spine, e.g. fractures resulting from falls from standing height." Please change to "Lowtrauma fractures were defined as fractures resulting from falls from standing height."

Done, the sentence have changed on page 6 line 16.
- Patients and Methods section, Study Subjects part, line 6:
4. "Recent fracture was defined as hip fracture or related clinical signs/symptoms
occurring within 30 days of the study enrolment date: vertebral fracture or related clinical
signs/symptoms occurring within 3 months of the study enrolment date." Knowing that
2/3 of the vertebral fractures are asymptomatic, how did the authors date the vertebral
fractures?
2

As high proportion of the vertebral fractures are asymptomatic, to standardize the
recording method among sites, we took the date radiograph or X-ray report confirmed
as the date of verterbral fractures in this study, was mention on page 7, line 1.
- Patients and Methods section, Study Subjects part, line 16:
Please delete the commercial name of the drugs "(e.g. Centrum Plus, Oscal D, Fosamax
Plus)".

Done, the commercial name of the drugs have deleted from page 7 line 11.
- Patients and Methods section, Study Procedures part, line 13:
5. "BMD measured by dual energy x-ray absorptiometry of lumbar spine or hip were
recorded" Please change to ".... lumbar spine and hip ....".

Done, the sentence have changed on page 8 line 7.
- Patients and Methods section, Study Subjects part, last sentence:
6. "Safety and tolerability were assessed by laboratory and clinical review of adverse
experiences according to the real world data whenever applicable." This sentence is not
clear. "Safety and tolerability" of what? "adverse experiences" of what? There are no
such data in the Results section. Please clarify or delete.

As this was an observational study without administration of any therapeutic or
prophylactic agent under this protocol. The only safety measurements referred
to any adverse experiences related to protocol as reported by subject within 24
hours following a study visit completion. To avoid misunderstanding, this
sentence was deleted as the reviewer indicates, on page 9 line 9.
- Results section, line 8:
7. "Regarding the co-morbidity survey, only hypertension revealed a statistical difference
(p=0.033) between groups, ..." Does this difference remains significant after adjustment
on age (patients in the hip fracture group are older than patients in the vertebral fracture
group).

The re-analysis had been conducted as the reviewer indicates, there was no
statistical significant difference in hypertension between groups after
adjustment on age.
- Results section:
8. It has been published that there is a seasonal variation of vitamin D level. The authors
did not state if there was a difference between vitamin D results in cold and in hot
seasons

The mean vitamin D levels were slightly higher but no statistical difference in
summer and fall then in winter and spring season, were added in the manuscript
on page 11, line 1.
9. Does the difference between groups in i-PTH, serum calcium and phosphorus remains
significant after adjustment on age?
3

The re-analysis had been conducted as the reviewer indicates. After adjustment
on age, the difference between groups in serum calcium (p<0.001), serum
phosphorus (p=0.005) and BAP(p<0.001) remains significant.
- Discussion section, line 2:
10. "The results of this study have shown a high prevalence of vitamin D inadequacy
across all age groups among women ...." The authors did not present the results by age
groups. Therefore, they can not discuss this point. Either, they present the results by age
groups or they delete "across all age groups".

We add the paragraph of age group analysis results in results section per the
reviewer’s comments "When analyzing the mean serum 25(OH)D levels and
prevalence using three cut-off points (<30, <20 and < 10 ng/mL) by different
age groups (<60; 60~69; 70~79; 80~84; ≥85 years), the results were consistent
across all age groups with no statistical difference in the vitamin D levels or
proportion of patients with vitamin D levels lower than 30 ng/mL, 20 ng/mL or
10ng/mL in any of the age groups (Table 5)." , were added in the manuscript on
page 11, line 3.
- Discussion section, line 30:
11. "The relationship of 25(OH)D level and i-PTH, which is consistent ..." Please delete
"which".

Done, have deleted on page 12, line 18.
- Discussion section, line 34:
12. "r=0.22436", Please change to "r=0.22".

Done, have changed on page 13, line 3.
- Discussion section, limitations of the study paragraph:
13. Please delete the sentence "However, there is evidence that vitamin D insufficiency or
even deficiency is, undoubtedly, common in these post-menopausal women who suffered
fragility fractures."

Done, have deleted on page 14, line 4.
- Conclusions section:
14. Last sentence. Please delete "to plausibly decrease the risk of fragility fracture." As,
by their work, the authors did not prove that and therefore can not conclude this
conclusion.

Done, have deleted on page 14, line 11.
- References:
15. Reference 15 is the same as reference 11. Please delete reference 15 and change the
number of the following references in the reference section as well as in the text
accordingly.

Done, we have deleted reference 15, added reference 6 (MC Chapuy et al) per
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reviewer- Mr. Edgard Delvin’s suggestion and changed the reference number
accordingly, on page 16.
Reviewer #2 (Edgard Delvin)
Reviewer's report
General comments
This report is well written and the protocol adequate. The results are within the scope
of the objectives. The research protocol limitations are explained in the discussion.
The subject however is not new, and there are a number of similar reports in other
populations.
Specific comments
Title
The title is misleading. This report does not address a representative Taiwanese female
population. There is a selection bias by excluding supplemented women. Therefore the
title should include the mention non- supplemented.

The title has been changed to “Vitamin D Status in Non-Supplemented
Postmenopausal Taiwanese Women with Osteoporosis and Fragility Fracture”
as the reviewer indicates, on page 1, line 2.
Abstract
I think that it is inappropriate to mention the prevalence of vitamin D inadequacy in
postmenopausal women with OP in Taiwan as those supplemented with vitamin D were
excluded. The results reflect the vitamin D status in a group of selected nonsupplemented elderly women.

We have specified the study population as non-supplemented women in
abstract section as the reviewer indicates, on page 3, line 17, and page 4, line 9.
Introduction
The authors mention that there are efficacious & safe drugs to treat OP. Questions &
comments: They should mention what they are and give appropriate references. What are
drugs: Pamidronate & other bisphosphonates? The supplementation study of MC Chapuy
et al published in the New England Journal of Medicine should be referred to. It was
among the first to show that vitamin D + Calcium supplementation was effective.

We have added reference 6 (MC Chapuy et al) per reviewer indicates and
changed the reference number accordingly, on pages 16.
Patients & Methods
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“A total of 199 subjects were evaluated for inclusion with 194 subjects meeting all of the
eligibility criteria. Five subjects were excluded due to renal or liver impairment (4
subjects with Cr > 1.6 mg/dL and 1 subject with ALT > 3 times ULN”.
Comment: There is redundancy with the beginning of the result section. These 2
sentences should be included (combined) in the results section.

Done, these 2 sentences were combined in the 1st sentence in the results section
as the reviewer suggests. On page 9, line 12
Statistical analysis
“Safety and tolerability were assessed by laboratory and clinical review of adverse
experiences according to the real world data whenever applicable”.
Comment and question: Safety & tolerability assessment is usually done in the context
of treatment. For example safety & tolerability assessment would be done in the case
of vitamin D supplementation or bisphosphonate treatment. Could the authors explain?

As this was an observational study without administration of any therapeutic or
prophylactic agent under this protocol. The only safety measurements referred
to any adverse experiences related to protocol as reported by subject within 24
hours following a study visit completion. To avoid misunderstanding, this
sentence was deleted as the reviewer indicates, from page 9, line 9.
Is vitamin D2 used in Taiwan? Is the Diasorin assay measuring 25(OH)D2? If not the
levels reported may be falsely low.

Vitamin D2 is not available in Taiwan, and the Diasorin assay measured both
D2 and D3 to ensure accurate assessment of vitamin D, was mention on page 8,
line 11.
Results
Among several types of calcium-rich and vitamin-containing food, including milk, yolk,
cod-liver oil, fatty fish, and mushroom, the hip fracture group had higher proportion of
women taking cod-liver oil and eating more fatty fish and mushrooms (46.9% vs.
27.2%) than the vertebral fracture group.”
Comment and question: Theoretically those consuming fatty fish, cod-liver oil &
mushrooms should have a higher vitamin D intake. However increased Vitamin D intake
with low calcium intake may exacerbate bone resorption, due to increased1,25(OH)2D3
production. Were 25(OH)D3 and 1,25(OH)2D3 levels different in women consuming
more fatty fish, cod-liver oil?

There was no statistical significant difference in 25(OH)D3 in women
consuming more fatty fish or cod-liver oil (p=0.715).
“Overall, the mean level of 25(OH)D was 21.1±9.3 ng/mL, ranging from 4.0 to 57.5
ng/mL.” Could the 25OHD concentration distribution be skewed since 86.6% had levels
lower than 30 ng/ml? This seems to be confirmed by subdivision of inadequate levels.
Perhaps median & interquartile should be used?
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
The median (20.0) and interquartile(Q1:15.7, Q3:26.2) had been added in the
sentence as the reviewer indicates. On page 10, line 10.
“ there were significantly higher mean i-PTH levels (45.7 vs. 35.8 pg/mL), lower mean
serum calcium (8.2 vs. 8.9 mg/dL), lower mean serum phosphorus (3.5 vs.4.2 mg/dL)”.
What are the age-matched reference values for the markers? Are PTH levels showing
mild or important secondary hyperparathyroidism in face of low serum calcium? What
are the age-matched reference values for serum Pi & BAP?

We only have general reference range for i-PTH(14~72pg/mL), serum
calcium(8.3~10.6mg/dL) and serum phosphorus(2.4~5.1mg/dL), but no
specific age-matched (postmenopausal woman) references, and the mean levels
in both groups were all within the reference ranges except slightly lower serum
calcium in hip fracture patients (8.2 mg/dL). For BAP, the mean levels in hip
fracture or vertebral fracture were all within the reference range (<22.4 μg/L in
postmenopausal woman).
Discussion
“ In our study, the prevalence of vitamin D insufficiency”. See above comments.
“probably due to inclusion of subjects with confirmed fragility fracture either admitted
to hospital or from outpatient clinics and due to exclusion of patients taking vitamin D
supplementation regularly (2800 IU vitamin D per week or 400IU vitamin D per day).”
What would be the clinical status of these patients? Would they have less fracture? I
think that comparing these 2 groups in terms of fracture rates, and bone metabolism
biomarkers would greatly improve the report.

In this study, we enrolled postmenopausal women with osteoporosis and
fragility fractures without vitamin D supplement, thus we did not have the
clinical status of patients taking vitamin D supplementation regularly.
“The results were consistent with the previous findings that lower vitamin D levels were
associated with a higher risk of hip fracture” There is no comparison group in this study.
The conclusion is inferred from another study in a different population with a different
genetic background and environment. It could perhaps be said that low vitamin D levels
are associated with a high hip fracture rate.

The sentence was revised to “The results were consistent with the previous
findings that low vitamin D levels were associated with a high hip fracture
rate.” as the reviewer indicates. On page 12, line 7.
“ The relationship of 25(OH)D level and i-PTH, which is consistent with previous
reports that the synthesis and metabolism of vitamin D is (should be are coupled)
coupled to calcium homeostasis and is regulated by PTH”. It is the synthesis of
1,25(OH)2D3 which is regulated by PTH & Ca++ and also by FGF23/Khloto. Have the
1,25(OH)2D3 been measured. In a state of inadequacy with presumably secondary
hyperparathyroidism these might be elevated. There could possibly be an increasing
gradient as serum 25(OH)D3 decreases.

1,25(OH)2D3 was not measured in this study,.
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Level of interest:An article of limited interest
Quality of written English:Acceptable
Statistical review:Yes, but I do not feel adequately qualified to assess the
statistics.
Declaration of competing interests:
I have no competing interests
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