The Effects of Vitamin D on Preventing Hyperglycemia and a Novel Approach to Its Treatment

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear editor and authors, I appreciate the opportunity to review this work. I think that a very complete review has been done on vitamin D and in that sense it is a very good job, but I also think that what it only does is put together all the advances that exist on the vitamin in relation to diabetes without contributions new to knowledge. In that sense I have to leave the decision of its publication exclusively in the hands of the editor, since I do not know the policy of your journal.

Author Response

Good evening,

Thank you for your keen review. Please find the attachment for your comments. Thank you for sparing time to review my article

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

I congratulate the authors for their extensive literature search concerning the relationship between vitamin D and hyperglycemia. However, using RCT data would strengthen the conclusion rather than just using case studies (in tables) as evidence. Apologies if I missed this: the authors at the beginning of the manuscript mentioned that they would discuss data from a few RCTs, but I could not locate them in the text. This is only the major concern I have with this manuscript. 

Comments on the Quality of English Language

Fine. 

Author Response

Good evening sir/madam

Thank you very much for spending your valuable time for our article. Please find the attachment for your comments and do it needful sir

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

 

This review described the potential role of vitamin D in treatment of each of the three types of diabetes mellitus.  The authors are sometimes not clear in their purpose, but with revision could provide useful information.  There is some confusion about whether prevention was to be included as the evidence they provide using case studies should be treatment (or management).  Epidemiological evidence, cohorts, and large clinical trials provide information on prevention.  

1.      The case study approach was not explained. Was a search conducted for the studies? Those presented for type 1 in Table 2 were uneven – only ref 19 was treatment of patients. A quick search in Pubmed revealed 100’s of studies of vitamin D and DMT1 thus some criteria for inclusion is needed.  For cases of DMT2, studies presented in Table 3 are a reasonable representation of patients being given vitamin D. In Table 4, only studies from references 32 and 33 are treatment of patients.

2.      The order of topics needs some clarity. Section 8 is completely out of place and can be omitted. Section 6 is somewhat repetitive and some of the information presented here should have been described earlier.  The paper’s logical end would be section 5 which is a perspective on information provided earlier, yet these conclusions are not evidence-based (as promised in line 207) as no references are provided in this section.

3.      Figure 4 does not include the paracrine/autocrine pathway for synthesis of calcitriol inside cells. It shows only the endocrine (i.e., renal) pathway for synthesis of circulating calcitriol.  

4.      Table 5: “Some of the marketed supplements of vitamin D” is incomplete. No information is given for each type of product and dosages and routes of administration are missing. What is the purpose of this Table? Every country is different so a table for what is relevant to a particular country could be made.  As the authors are in India, a Table specific to India would be interesting.  Note error in row 1 of the table- it should be D3.

5.      Minor comments:

a.      Line 72: change “were” to are

b.      Lines 40-77 – difficult to read- make paragraphs. Too much discussion of world diabetes rates. Provide a few key numbers. Divide into the 3 types consistently.

c.      Line 80 – you say vitamin D is “vitamin D”. What does this mean?

d.      Line 96 – specify UVB not “sunshine”. Later you do mention UVB in section 6 which is more precisely written. That level of precision is needed here.

e.      Line 114: not “plants”. D2 made by fungi.

f.       Line 119 – in describing cereals and milk use the word “fortification”. Many countries are now doing this but in low levels and in different foods. Some fortification is required by law and some id voluntary by the manufacturer.

g.      Line 123 – RDAs are used in some countries and values described are for USA, Canada and some other countries. But not all use these values. Cite key references. For example Bouillon R. Comparative analysis of nutritional guidelines for vitamin D. Nat Rev Endocrinol 2017;13:466–79. https://doi.org/10.1038/nrendo.2017.31.

Author Response

Good evening sir/madam

Thank you very much for spending your valuable time for our article. Please find the attachment for your comments and do it needful sir. According to your Instructions we concluded our article

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

Thanks for addressing my concern. 

Comments on the Quality of English Language

Fine.

Author Response

Dear sir/Madam

Greetings for the day. Thank you again for spending your valuable time for reviewing my paper.

Thanking you

Dr. M. Suchitra

Reviewer 3 Report

Comments and Suggestions for Authors

Authors-

You have made significant changes to the manuscript and I see a better picture of the role of vitamin D in DM.

There are a few points remaining.

1.      In the revised figure I still do not see the paracrine/autocrine pathway. It is separate from that of the kidney and the calcitriol made stays within the cell or tissue. A good example is seen here in this open access paper:

Fletcher J, Bishop EL, Harrison SR, Swift A, Cooper SC, Dimeloe SK, Raza K, Hewison M. Autoimmune disease and interconnections with vitamin D. Endocr Connect. 2022 Mar 31;11(3):e210554. doi: 10.1530/EC-21-0554. PMID: 35196255; PMCID: PMC9010814.

2.      A minor point- The change you made in response to a previous comment is not correct –

c.            Line 80 – you say vitamin D is “vitamin D”. What does this mean?

Response 5(C): Thank you for pointing out this. It’s a typographical error it is Vitamin D, also known as the “Calcitriol”.  Vitamin D, also known as the "Calcitriol," has recently gained new attention due to…

 However, I think you mean “cholecalciferol”. Or, perhaps you mean to say that the activities of vitamin D are due to its active form calcitriol. What the intent, please correct.

Comments on the Quality of English Language

English is fine. The authors have made a few small errors in their revision. For example, UVB radiations should be UVB radiation.

Author Response

Dear sir/Madam,

Greetings for the day. Thank you for spending your valuable time to keen review of my paper.

According your Instructions 

1.Now we added paracrine pathway in Figure

2.In line 80 ,Vitamin d also known as Cholecalciferol(d3)

Thanking you

Regards

Dr. M. Suchitra