Reviewer’s report
Title: 
Serum Antioxidant Vitamin Concentrations and Oxidative Stress Markers
Associated with Symptoms and Severity of Premenstrual Syndrome: A
Prospective Cohort Study
Version: 
0 
Date: 
02 Apr 2020
Reviewer's report:
This manuscript is the largest study to date that examines several antioxidants
and an oxidative stress biomarker and their relationship to premenstrual
symptoms. 
1) Lines 54-56: please include oxidative stress in the research aim of the
manuscript similar to the abstract. 
2) Lines 133-140: attributing all four of these pms definitions to Yonkers is
misleading. 
3) Did each of the 4 cravings symptoms count as individual symptoms in the 4
pms definitions (e.g., could someone have had multiple moderate/severe
cravings count towards 4 of the the 5+ or 8+ symptoms). 
4) How were covariates selected? 
Were other lifestyle factors that may be related
to antioxidant/ oxidative stress and related to PMS examined (e.g., physical
activity, smoking, alcohol, NSAID use)
5) Why the discrepancy in cycle numbers meeting pms definitions and
moderate/severe symptoms between this manuscript and the prior manuscript by
Gollenberg 2010?
6) Is there biological plausibility for the antioxidant - premenstrual symptom
associations seen?
7) Discussion of limitations should include that the definitions of pms have
limited timing information (i.e., do symptoms happen only in the week prior to
menstruation and disappear with in a few days of menses start) and that impact
on function (e.g., work, family, friends, etc.) is not taken into account. 
8) While the BioCycle study is prospective, this analysis appears to be cross-
sectional as described in the methods (antioxidant/oxidative stress measures
averaged over entire cycle and symptoms assessed during same cycle). 
This
should be included as a limitation, as it is unclear whether there is reverse
causality. 
Were any secondary analyses done to examine timing? Additionally,
did the antioxidant levels and oxidative stress measure vary during the menstrual
cycle and how did the compare by women with probable pms vs without?
Are the methods appropriate and well described?
If not, please specify what is required in your comments to the authors.
No
Does the work include the necessary controls?
If not, please specify which controls are required in your comments to the
authors.
Yes
Are the conclusions drawn adequately supported by the data shown?
If not, please explain in your comments to the authors.
Yes
Are you able to assess any statistics in the manuscript or would you
recommend an additional statistical review?
If an additional statistical review is recommended, please specify what aspects
require further assessment in your comments to the editors.
I am able to assess the statistics
Quality of written English
Please indicate the quality of language in the manuscript:
Acceptable
Declaration of competing interests
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