Micronutrient Differences in Conventionally and Organically Produced Foods

Round 1

Reviewer 1 Report (Previous Reviewer 2)

Comments and Suggestions for Authors

The authors presented a manuscript entitled "Micronutrient Differences in Conventionally and Organically Produced Foods" in which a literature review comparing conventionally and organically produced foods was performed. Teh article is better discussed now, the tables aid in visual recognition of the differences but there is lack of standard format between the tables and other issues addressed ahead.

I believe the tables must have their legend on their upper part instead of their lower part.
Table 1a both labels with "Exact value was not provided but statistical significance (p<0.05) was present". The statistical significance does not state which comparison was used with which group, and even if it showed, it is not relevant to compare quantitatively with the organic produce. It is suggest that the authors either delete these rows or find quantitative information for the conventional produce.

There is a clear discrepancy:  "In Egypt organic eggs contained significantly higher vitamin A than conventional eggs [28]" 
Organic
Egg 1.35 ± 0.0483 mg kg -1 (vitamin A)
Conventional
1.54 ± 0.0672 mg kg -1 (vitamin A)
Source [28]

The tables have different lines and format.

Wht do the authors mean with statistical significance, there are many statistical methods and many more ways to compare groups and samples in a study, this is extremelly vague. Alas, this is a table not a figure. "Figure 1. Summary of food products that contain higher levels of the given vitamin in
discussion based on literature reviewed. Statistical significance (p) was based on the study
conducted in the given source. Non-significant differences are demonstrated with “n.s.”"

Table 7 has no unit.

There is no conclusion?

Author Response

Review Report 1

(reviewer comments in italics to be more visibly different from our responses)

I believe the tables must have their legend on their upper part instead of their lower part.
Table 1a both labels with "Exact value was not provided but statistical significance (p<0.05) was present". The statistical significance does not state which comparison was used with which group, and even if it showed, it is not relevant to compare quantitatively with the organic produce. It is suggested that the authors either delete these rows or find quantitative information for conventional produce.

We thank the reviewer for this suggestion. We have moved the table legends to the upper portion of each table to improve clarity and consistency. In addition, we removed rows in Table 1a that reported only statistical significance without quantitative values to provide a meaningful comparison.

There is a clear discrepancy:  "In Egypt organic eggs contained significantly higher vitamin A than conventional eggs [28]"
Organic
Egg 1.35 ± 0.0483 mg kg -1 (vitamin A)
Conventional
1.54 ± 0.0672 mg kg -1 (vitamin A)
Source [28]

This was an oversight on our part, and after checking the sources again, we have corrected this error.

The tables have different lines and format.

We thank the reviewer for carefully examining our table formatting. We have ensured that the tables are formatted consistently throughout the manuscript. Specifically, we corrected Figure 1 to refer to Table 1, added units to Table 8, and standardized formatting such that quantitative tables present numerical values only, while qualitative tables are clearly described.

What do the authors mean by statistical significance? There are many statistical methods and many more ways to compare groups and samples in a study. This is extremely vague.

We thank the reviewer for raising this point. We clarified in the manuscript that statistical significance is reported as defined in the original studies and, because study designs vary, these values should not be interpreted as directly comparable across food items or production systems. This is seen in lines 266-269.

Alas, this is a table, not a figure. "Figure 1. Summary of food products that contain higher levels of the given vitamin in discussion based on literature reviewed. Statistical significance (p) was based on the study conducted in the given source. Non-significant differences are demonstrated with “n.s.”"

The reviewer is indeed correct, this was a figure in earlier drafts and we neglected to update that. We changed this to now correctly indicate table.

Table 7 has no unit.

This was an oversight on our part, and we added this to the Table caption.

Is there no conclusion?

We reworded the discussion to have a short concluding paragraph (lines 445-449).

Reviewer 2 Report (Previous Reviewer 1)

Comments and Suggestions for Authors

This manuscript examines existing reports of micronutrients, including vitamins, minerals, and other bioactive compounds, in plant and animal-based foods from organic and conventional systems. A literature review was conducted after a preliminary screening of abstracts to determine their relevance to the study’s purpose, 120 articles were included. Reports are reviewed describing higher amounts of vitamin C, vitamin E, magnesium, iron, and polyphenols in organic produce and of certain animal products showing more antioxidants or fat-soluble vitamins while simultaneously other authors found no noteworthy differences, and also some others report higher nutrient levels in conventionally raised foods. Compared to the initial manuscript the quality was far improved with a more structured backbone and explicit developed methodology which was critical for the scientific quality assessment. Most of the lacking points from previous suggestions and corrections were well addressed and for that I congratulate the effort of the authors. Specifically regarding point 12) of the previous revision I would like to leave the authors at ease to chose the best presentation mode. This suggestion was only presented to make the paper more competitive compared to previous review articles in the field.

 

I still recommend some minor corrections to the manuscript:

 

Line 291: "Smith-Spangler et al.,(...). Please provide the number of the reference between squared brackets after the comma. E.g.: Smith-Spangler et al., [110]

 

The same should be followed for:

 

Line 298: "Hadayat et al. "

 

Also, please make sure that the identification of tables and figures are accordingly to the journals guidelines.

 

Overall, the manuscript was indeed improved regarding the methodology chosen to be presented by the authors and the limitations were also addressed within the written work with suggestions for future works.

Author Response

Review Report 2

I still recommend some minor corrections to the manuscript: Line 291: "Smith-Spangler et al.,(...). Please provide the number of the reference between squared brackets after the comma. E.g.: Smith-Spangler et al., [110] The same should be followed for: Line 298: "Hadayat et al.

We thank the reviewer for their kind words and have addressed the minor corrections.

Also, please make sure that the identification of tables and figures are according to the journal's guidelines.

Thank you for mentioning this. We have revised the identification of tables to align with the journal’s guidelines and adapted the figure into a table as that is more appropriate.

Reviewer 3 Report (New Reviewer)

Comments and Suggestions for Authors

This manuscript addresses an important and highly debated topic—micronutrient differences between organic and conventional food systems. The topic is appropriate for the journal and of interest to both researchers and the public. However, in its current form, the manuscript suffers from significant methodological, structural, and interpretative weaknesses that prevent it from meeting the standards required for publication.

• The review lacks a clearly defined, reproducible, and rigorous methodology. While the authors state that PubMed was used and that “over 120 articles” were screened, there is no transparent description of search strategy, inclusion/exclusion criteria, study quality assessment, or risk of bias evaluation. The absence of a structured framework (e.g., PRISMA or scoping review methodology) severely limits the credibility and reproducibility of the conclusions. Furthermore, the decision to include only studies showing “clear organic or conventional advantage” introduces a high risk of selection bias, potentially exaggerating observed differences.
• Throughout the manuscript, associations between farming system and micronutrient content are frequently interpreted in causal language. However, most of the cited studies are observational and highly heterogeneous in terms of cultivar, climate, soil composition, fertilization strategy, and post-harvest handling. I think you shoud add a dedicated subsection clearly explaining confounding variables (genotype, climate, soil microbiome, post-harvest storage). Also, it is advisable to avoid generalizations such as “organic foods provide greater antioxidant protection” unless supported by consistent multi-study evidence.
• The manuscript focuses almost exclusively on total micronutrient concentrations while only briefly mentioning bioavailability. However, bioavailability is central to nutritional relevance and may differ substantially between food matrices, fat content, fiber content, and preparation methods. Without addressing bioavailability in depth, the conclusions regarding nutritional superiority remain incomplete and potentially misleading. I think you should expand the discussion on micronutrient bioavailability (especially for iron, zinc, carotenoids, and vitamin K).
• The heavy metal section raises important safety implications but currently lacks adequate toxicological context. While lower cadmium and lead levels in organic foods are highlighted, the manuscript does not sufficiently compare observed values with established safety thresholds, nor does it address exposure from total dietary intake. This leads to potential overstatement of health risk.
• The review reads largely as a catalog of isolated findings rather than a coherent synthesis. Vitamins, minerals, and polyphenols are presented as separate silos, with limited effort to integrate overarching biological mechanisms or agricultural principles across nutrient categories. I think you should strengthen cross-cutting synthesis in the Discussion, identify unifying mechanisms (e.g., nitrogen availability, plant stress responses, microbial activity) and clearly articulate what the cumulative evidence suggests, rather than repeating individual nutrient trends.
• The concluding statements suggest that paying a premium for organic foods may not be justified based on micronutrient content alone. While this may be true, the present review design does not justify such a strong consumer-facing conclusion, given the non-systematic approach, exclusion of null findings, and lack of bioavailability analysis. Please reframe conclusions to reflect uncertainty, heterogeneity, and knowledge gaps.

Author Response

Review Report 3

The review lacks a clearly defined, reproducible, and rigorous methodology. While the authors state that PubMed was used and that “over 120 articles” were screened, there is no transparent description of search strategy, inclusion/exclusion criteria, study quality assessment, or risk of bias evaluation. The absence of a structured framework (e.g., PRISMA or scoping review methodology) severely limits the credibility and reproducibility of the conclusions. Furthermore, the decision to include only studies showing “clear organic or conventional advantage” introduces a high risk of selection bias, potentially exaggerating observed differences.

 

We thank the reviewer for raising this concern. We have expanded the Methods section to better describe our search strategy and added a supplementary file detailing the keywords used. We also acknowledge that our review did not follow a meta-analysis approach and added details to be as specific as possible for our non-exhaustive yet thorough review (lines 53–58 and 60–65). Additionally, we clarify that studies reporting no significant differences were included and discussed, and that this restriction applied only to the summary table, which was intended to highlight directional findings for ease of comparison rather than to be inclusive of the full review (lines 255–261).

 

Throughout the manuscript, associations between farming system and micronutrient content are frequently interpreted in causal language. However, most of the cited studies are observational and highly heterogeneous in terms of cultivar, climate, soil composition, fertilization strategy, and post-harvest handling. I think you shoud add a dedicated subsection clearly explaining confounding variables (genotype, climate, soil microbiome, post-harvest storage). Also, it is advisable to avoid generalizations such as “organic foods provide greater antioxidant protection” unless supported by consistent multi-study evidence.

 

As suggested, we have strived to remove definitive claims and generalizations throughout the manuscript. The Discussion has also been further revised with focus on confounding factors, elaborating variables such as genotype, climate, soil composition, and post-harvest handling, attempting to avoid simply restating prior statements (lines 372–416).

 

The manuscript focuses almost exclusively on total micronutrient concentrations while only briefly mentioning bioavailability. However, bioavailability is central to nutritional relevance and may differ substantially between food matrices, fat content, fiber content, and preparation methods. Without addressing bioavailability in depth, the conclusions regarding nutritional superiority remain incomplete and potentially misleading. I think you should expand the discussion on micronutrient bioavailability (especially for iron, zinc, carotenoids, and vitamin K).

 

Thank you for mentioning this.  While our main focus remains total micronutrient concentrations, we have expanded the Discussion in the sections where bioavailability was reported, particularly for iron, zinc, carotenoids, and vitamin K, as requested. These additions aim to address the reviewer’s concerns without changing from the primary focus of the review. This can be seen in lines 111-119, 241-246, 283-288.

 

The heavy metal section raises important safety implications but currently lacks adequate toxicological context. While lower cadmium and lead levels in organic foods are highlighted, the manuscript does not sufficiently compare observed values with established safety thresholds, nor does it address exposure from total dietary intake. This leads to potential overstatement of health risk.

 

Thank you for this valid observation. We have added context to the heavy metal section to compare observed cadmium and lead levels with established safety thresholds, with these additions aiming to reduce the risk of overstating health risks.

 

The review reads largely as a catalog of isolated findings rather than a coherent synthesis. Vitamins, minerals, and polyphenols are presented as separate silos, with limited effort to integrate overarching biological mechanisms or agricultural principles across nutrient categories. I think you should strengthen cross-cutting synthesis in the Discussion, identify unifying mechanisms (e.g., nitrogen availability, plant stress responses microbial activity) and clearly articulate what the cumulative evidence suggests, rather than repeating individual nutrient trends.

 

We agree this will be beneficial to the review and have revised the Discussion to present a more integrated synthesis rather than simply repeating individual findings (lines 372 to 416).

 

The concluding statements suggest that paying a premium for organic foods may not be justified based on micronutrient content alone. While this may be true, the present review design does not justify such a strong consumer-facing conclusion, given the non-systematic approach, exclusion of null findings, and lack of bioavailability analysis. Please reframe conclusions to reflect uncertainty, heterogeneity, and knowledge gaps.

 

We agree with the suggestions provided. After incorporating the previous suggestions and expanding the Discussion to highlight unifying mechanisms, we believe the concluding statement is now better supported. We also emphasized heterogeneity and knowledge gaps in the limitations and throughout the Discussion to ensure our conclusions accurately reflect currently available literature.

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This research examines existing reports of micronutrients, including vitamins, minerals, and other bioactive compounds, in plant and animal-based foods from organic and conventional systems, specifically reviewing the variable amounts which were found higher for vitamin C, vitamin E, magnesium, iron, and polyphenols in organic produce and of certain animal products showing more antioxidants or fat-soluble vitamins. On the other hand the authors, refer that many studies found no noteworthy differences and some authors report higher nutrient levels in conventionally raised foods underlining that factors such as soil fertility, fertilizer use, and climate conditions may then influence micronutrient food content as much or more than farming method. From the overall research, authors conclude that while organic foods may sometimes provide enhanced micronutrient levels, the overall evidence from existing literature does not support a consistent nutritional advantage associated with organic production.

Lines 37-40: "This review examines differences in the micronutrient composition of plant- and animal-based foods produced under organic and conventional systems, with a focus on their potential impact on human health."

The aim of this review is to make an objective comparison between the micronutrient of plant and animal based foods produced under organic and conventional systems it would benefit a lot to the publication to add numerical data. I recommend to make a graphical comparison for a better visual comprehension by the readers of the analysis obtained by the latest available studies.

Materials and methods: No reference is made to the methodology followed by the researchers for possible reproduction of the study.

Was there a comprehensive search on the topic? If so, when was the data extraction made?

How was the search made? Which databases were selected? Which keywords were used for the literature search? Was there a string comprising several keywords?

Which period time was considered to obtain the studies? The last 5 years?

Which exclusion and inclusion criteria were selected and the rationale behind that selection?

2. Micronutrients - is this section the equivalent to a Results and Discussion Section?

The micronutrients section comprises a summary of the comparison of each of the micronutrients selected by the authors (vitamins, minerals and polyphenols). I recommend to add a comparison table of the main studies found, at least in the last 5 years for each of the micronutrient explored considering:

- how many comparative analysis were made in each study of the food item/micronutrient (C1)

- if only one analysis, were the results significant between organic or conventionally produced food (C2)

- If more than one analysis was made, if one or more item shows significant differences or not. And if not all micronutrients showed a significant difference, if at least one item showed a significant difference (C3)

- Insert a table conferring the final results

Food item	Micronutrients	Results			Total	Relative frequency (%)
		C1	C2	C3		C1	C2	C3

- Also, it would be interesting to introduce data/graphs comparing the nutritional and residual superiority between groups of organic and conventional fruits, vegetables, and others.

- it would be interesting to correlate the differences found with the production conditions (agricultural practices, climate and soil) /genetic origin.

Table 1 - please provide references in the differences column. If a

Lines 118-119: "In addition, organic crops face greater biotic and abiotic stresses". It would be intesting for the reader, for the authors to discriminate the kind of biotic and abiotic stresses that these cropes face.

Lines 211-212: " other factors such as genetic makeup, climate, and heat treatment methods". Please, provides examples of crops that might favored by each of factors mentioned: genetic makeup, climate and heat treatments.

I strongly suggest for the authors to consider heavy metals comparison between organic and conventionally produced food.

Conclusions:

Line 221-224: "In some cases, conventional foods can equal or exceed organic counterpart micronutrients, and bioavailability may then be more important than total content. Given these mixed findings, there is no clear consensus that organic foods consistently provide superior micronutrient value. "

These conclusions, in line with some previous authors, could be more supported if a deeper work numerical and comparison of results as shown above is developed and presented in the manuscript. Also, a deeper numerical work would provide more content to strentgthen the results discussion as would a more explained methodology. So, I deeply encourage the authors to add the requested information to add value to the manuscript.

I note that the abstract overall describes the analysis made by the authors, but it could also benefit if the authors include the number of studies analysed, including the convergent and divergent studies, and how they were searched for systematizing the summary of the scientific research.

Reviewer 2 Report

Comments and Suggestions for Authors

The authors presented a manuscript entitled Micronutrient Differences in Conventionally and Organically Produced Foods, in which a quick review about micronutrients presence between organic and non organic foodstuff was evaluated. I found the article lacking in major points for the presentation and discussion: there is no section or mention on how the review process was made; each individual discussion is shallow and has no numeric comparison between data; comparison tabletes are needed; The conclusion needs to reference more direct data.

Reviewer 3 Report

Comments and Suggestions for Authors

The paper aims to highlight the micronutrient differences between conventionally and organically produced foods. The approach taken could distinguish it from related research. The introduced idea appears promising and may inspire others to develop and implement environmentally friendly methods that enhance the bioaccumulation of key factors.

As the authors emphasized, establishing a clear relationship between production technology and the quantity of biomolecules in the final product is a challenging task. It is also helpful to specify the methodology used to detect the analyte of interest in samples, the harvest time (for vegetables), and data related to farming practices such as crop rotation, soil type, and climatic conditions. The regulation definitions for organic and conventional products were not mentioned. Providing such information through a review-type article could be beneficial.

Given the paper’s scope and the journal's scientific standards, the manuscript needs significant improvements. Including additional information and review elements, such as figures (conceptual charts) and new tables, could add valuable insights.

The manuscript contains only two tables and no figures. Table 1 presents information on the functions of B vitamins, observed differences, explanations, and sources in both organic and conventional foods. Relevant references must support each statement.

The study also lacks a discussion of limitations and future research directions.