Vitamin C × LDL cholesterol: four-week add-on effect with shared beetroot juice
research showsVitamin C alone is not established to lower elevated LDL consistently. An earlier placebo-controlled meta-analysis found a reduction, while a later review found no significant overall lipid effect; populations and durations differ. The fixed-time direct evidence selected here concerns adding C1000mg/day for four weeks in untreated high-LDL adults who consumed beetroot juice in both conditions. The reported between-treatment contrast is−12.9mg/dL(P=.049), a secondary-outcome signal in a small completer crossover trial. It does not establish C monotherapy, a statin add-on effect or prevention of cardiovascular events. [S1 §3.6/Fig5B; S2–S3]
ads claimThis task addressed clinical LDL evidence; advertising claims were not systematically collected. This does not mean no advertising exists.
Seven original content assessments
- Directness — There is a direct four-week LDL contrast in untreated adults with high LDL, but only with shared beetroot juice. C-monotherapy reviews remain separate.
- Denominators/design — 23randomized,18completers and16RHI observations are distinguished;18crossover participants are not counted as36.
- Numbers/arithmetic — BodySEM, plotted between-treatment contrast and P were compared; reported and reconstructed CIs are distinguished. No unit conversion or arbitrary baseline percentage calculation was made.
- Bias/registration — Completer analysis, differential attrition, multiplicity, nonsignificant principalRHI/secondaryLDL and unverified registration are disclosed.
- Counterevidence/families — Positive2008 and nonsignificant2016/T2D review findings are presented without pooling different diseases, cointerventions or times.
- Safety/independence — ActualGI/high-BP withdrawals are separated from general safety, and public funding from unverified product donation.
- Text/scope — Full bilingual text, seven axis reasons,12facets and unknown reasons share the same structure. Self-assessed documentA is distinct from efficacyC54, safetyCaution and external peer review.
Useful facts when choosing a product
- The selected trial reports two Nature Made vitamin-C capsules providing1000mg/day; exact salt/batch are unverified.
- Both conditions used70mL Sport Beet IT concentrated beetroot juice, with a reported nitrate amount400–450mg.
- The C comparator was matching corn-starch placebo. These study-product facts are not current sales, quality or efficacy certification, or purchasing advice.
Chamgap Semantic Classification Code
Permanent code issued
S.vitamin-c.oral-c-beetroot-add-on.untreated-high-ldl-age50-70.four-week-calculated-ldl-change.same-beetroot-cornstarch-placeboIngredients and nutrients > Vitamin C (existing canonical code vitamin-c) > Two vitamin-C capsules, total1000 mg; exact salt/molecular form/batch unverified. An add-on tested with shared70mL concentrated beetroot juice; not interchangeable with C monotherapy or a fixed combination product. > Nonsmokers aged50–70, LDL>130 mg/dL, RHI≤2, BMI18.5–34.9; no lipid-lowering therapy. Diabetes and major cardiovascular/renal/hepatic conditions excluded. Deficiency status not classified. > Within-person between-condition contrast of fasting calculated LDL-C changes over each four-week period (NC−N), mg/dL. Selected page endpoint, not verified registered primary; LDL was secondary in the paper. > Identical beetroot juice plus matching corn-starch placebo versus identical beetroot juice plus C. Not a comparison with C alone without juice, statins or multinutrient supplements.
Four-week calculated LDL change with add-on C under identical beetroot background. Whole original KOEN,54unknowns,C54 and actual raw receipts preserved; not C monotherapy, proven clinical importance or external peer review. The code identifies the intervention and claim; it never contains the evidence grade, score, or safety result.
Exact Claim Classification
These independent facets prevent evidence from different forms, routes, populations, effects, and comparators from being mixed.
| Intervention class | S · Supplement or nutraceutical |
|---|---|
| Canonical ingredient or intervention | Vitamin C (existing canonical code vitamin-c) |
| Source or part used | Purified supplemental nutrient; source substrate/manufacturing process unreported. Not assigned a botanical plant part. |
| Formulation or processing | Two vitamin-C capsules, total1000 mg; exact salt/molecular form/batch unverified. An add-on tested with shared70mL concentrated beetroot juice; not interchangeable with C monotherapy or a fixed combination product. |
| Route | Oral; intravenous/topical excluded. |
| Dose | Selected trial: C1000 mg/day, shared70mL beetroot juice (reported nitrate400–450mg); C/placebo one hour after juice. Study conditions, not personal dosing advice. |
| Duration | Four weeks per intervention, with14-day washout. The4–24-week durations of another meta-analysis are not pooled as a single four-week result. |
| Population | Nonsmokers aged50–70, LDL>130 mg/dL, RHI≤2, BMI18.5–34.9; no lipid-lowering therapy. Diabetes and major cardiovascular/renal/hepatic conditions excluded. Deficiency status not classified. |
| Effect or condition | Effect of C on LDL-C in adults with elevated LDL; the fixed-time direct contrast is limited to add-on C with shared beetroot juice. C-monotherapy evidence is a separate layer. |
| Primary endpoint | Within-person between-condition contrast of fasting calculated LDL-C changes over each four-week period (NC−N), mg/dL. Selected page endpoint, not verified registered primary; LDL was secondary in the paper. |
| Comparator | Identical beetroot juice plus matching corn-starch placebo versus identical beetroot juice plus C. Not a comparison with C alone without juice, statins or multinutrient supplements. |
| Duplicate-detection key | S|vitamin-c|oral|LDL-C|adults-high-LDL|no-completed-identical-claim-in-supplied-snapshot |
What the research actually shows
Vitamin C × LDL cholesterol: four-week add-on effect with shared beetroot juice
TASK-1058 / R01-098 · 2026-09-18
30-second answer
Vitamin C alone is not established to lower elevated LDL consistently. An earlier placebo-controlled meta-analysis found a reduction, while a later review found no significant overall lipid effect; populations and durations differ. The fixed-time direct evidence selected here concerns adding C1000mg/day for four weeks in untreated high-LDL adults who consumed beetroot juice in both conditions. The reported between-treatment contrast is−12.9mg/dL(P=.049), a secondary-outcome signal in a small completer crossover trial. It does not establish C monotherapy, a statin add-on effect or prevention of cardiovascular events. [S1 §3.6/Fig5B; S2–S3]
Original question and duplicate check
The original question asks what effects, differences or risks link vitamin C to LDL in adults with elevated LDL cholesterol. Proposed oral monotherapy, an LDL-concentration contrast and placebo were not assumed to be established facts. Full texts, evidence tables, sources and subclaims from22candidates were compared with the3169-record index. No identical completed C-LDL claim was identified, so this is new. Only bibliographic/trial-family material is reused from3017(BP/Fotherby2000) and3018(FMD/Gokce1999). The1585glycemic verdict and3115iron/3116safety verdicts remain boundary material. The097 audit finding no BP wording in the supplied043snapshot is preserved. Existing grades, scores and full bilingual originals are unchanged. [Input audit/candidate_fulltext_screen.json; full_index_screen.json; reference_reuse.json]
Primary page endpoint and time point
The primary page endpoint is the mean within-person between-condition contrast (NC−N) in fasting calculated LDL-C changes from baseline to the end of each four-week period, in mg/dL, among the same18participants. The primary time point is the end of each four-week intervention. This was selected because elevated-LDL eligibility, untreated status, a fixed time, direct LDL analysis and full-text access were established. Selection exposes the actual beetroot cointervention; it does not substitute a combination trial for a C-monotherapy claim. C-monotherapy meta-analysis remains a separate evidence layer, and4–24weeks is not turned into an invented common time. The18-month trial lacks a retrieved numeric contrast; the healthy trial lacks established high-LDL selection; combination products cannot isolate C; diabetes/dialysis involve different clinical populations. [S1–S6,S9–S11]
Actual population, intervention and measurement boundaries
Basaqr enrolled nonsmokers aged50–70 with LDL>130mg/dL, RHI≤2 and BMI18.5–34.9. Lipid-lowering therapy and diabetes/major cardiovascular, renal or hepatic disease were excluded. Both conditions included70mL concentrated beetroot juice (reported nitrate400–450mg), followed one hour later by C1000mg(two capsules) or matching corn-starch placebo. There was no C-without-beetroot arm, so synergy cannot be estimated. High-C foods were restricted during both intervention periods; the findings cannot simply be extended to an adequate-C usual diet. Mean plasma C was not used to diagnose deficiency. LDL-C was calculated by Friedewald from enzymatic TC/TG and precipitated HDL after a12-hour fast. It is not direct LDL, oxidized LDL, ApoB,non-HDL,Lp(a),TG,HDL or TC. Instructions to withhold medication before vascular testing are recorded study procedures, not personal treatment-change advice. [S1 §§2.1–2.6; Table1]
Denominators, crossover and bias
23participants were allocated to N→NC(n10) or NC→N(n13); nine in each sequence completed, giving18unique people. Their two conditions do not constitute36independent participants. LDL n18 differs from RHI n16. Pharmacy allocation, envelopes and matching capsules are described, but assessor-specific masking maintenance and registry-plan agreement are unverified. The two four-week periods were separated by14days; LDL carryover P=.78 does not prove exactly zero carryover. A contrast of changes is used, not simply final values or within-period significance. Analysis of18completers is not ITT for all23randomized participants. Multiplicity correction, imputation and a separate period/order-adjusted effect were not established. The paper’s principal RHI outcome was nonsignificant(P=.99); LDL was secondary. Agreement with an official registered primary is not claimed. [S1 §2.7,Fig2,§3.6; S8]
Evidence table — separate layers, not additive sample sizes
| Source | Design | Population / denominator | Exposure / time | LDL result | Role / limitation |
|---|---|---|---|---|---|
| S1 | Randomized double-blind crossover | 23 randomized (sequences10/13),18 completed (9/9); the same18 received both conditions. LDL n18, RHI n16. | Shared beetroot juice+C1000mg versus shared juice+placebo; four weeks each/14-day washout | Reported contrast of changes−12.9mg/dL (Fig5B), P=.049. Body mean changes: N+2.2±3.5SEM, NC−10.67±5.4SEM. No directly reported CI; present approximate CI−25.74 to−0.06. | Primary page endpoint/four weeks. Secondary LDL, completer analysis, multiplicity and reporting discrepancies. Not C monotherapy. |
| S2 | LDL11 comparisons within a13-RCT review | LDL549 unique individuals; C328/control310 include crossover participation and are not638 unique people. | C500–2000mg/day, placebo,4–24weeks (median10); total-cholesterol>200 eligibility | Pooled net change−7.9mg/dL,95%CI−12.3 to−3.5. Paper P=.000 is rounded reporting, not exact zero. | C-monotherapy layer. Not every participant had high LDL; change correlation.5/equal variance are the review authors’ assumptions. Included trials are not added again. |
| S3 | Adult-RCT systematic review/meta-analysis | Overall LDL denominator/numeric full table unavailable | At least two weeks; searches through August2014; varied trial conditions | Abstract: overall lipid effects nonsignificant. Subgroup signals are not generalized to the overall effect. | Counterevidence context, not direct repeated refutation of the same four-week beetroot contrast. Nonsignificance is not equivalence. |
| S4 | T2D RCT meta-analysis | Type2 diabetes; the LDL subset denominator is not equated with the number of all articles | C for at least two weeks, placebo/no treatment; crossover/active-control/combinations excluded | LDL WMD+2.73mg/dL,95%CI−1.72 to7.17,P=.229. | Kept separate for diabetes. Not exact zero or drug equivalence. |
| S5 | Hemodialysis RCT+nonrandomized-study review | 549 across12 studies is not the LDL-subset denominator | Oral4–52weeks,51.4–1000mg/day; LDL analysis reported for≥12weeks | Decrease WMD−24.81,CI−44.28 to−5.33,P=.008,I²79.1%; explicit unit/LDL-subset denominator unverified in the abstract. | 2025 publication (2024 online), renal special population. No invented unit or extension to general adults. |
| S6 | 2026 T2D C/E/C+E subgroup meta-analysis | Abstract52studies/1425 is an overall multivitamin/multi-outcome total | C/E/combination must remain distinct | C-only LDL estimate/CI absent from accessed abstract | Indirect recency layer. HDL/BP and vitaminE are not substituted for C-LDL. |
| S9 | Longer-term hyperlipidemia trial abstract | Abstract140 participants (83/57); overlap with review subset unresolved | L-ascorbic acid500mg/day,18months; sampling every six months | LDL reduction described; exact between-group contrast/CI unverified | Excluded as the numeric primary contrast; not added as independent participants. |
| S10 | Four-armRCT in healthy adults≥50, abstract | 120total, C/E/C+E/placebo; high-LDL selection unverified | 75days; exact C dose not established from this abstract | Reduction/significance described, without C-only effect/CI | Not primary because of healthy-population boundary and numeric gaps. |
| S11 | Open-label combination-product crossover | 20adults with LDL130–180mg/dL | Different monacolin-K combination products,eight weeks each/four-week washout | C-specific LDL effect not isolatable | Excluded because other ingredients including arginine differ; no attribution to C. |
Reported numbers and present calculations
The primary adopted reported values are the Fig5B contrast−12.9mg/dL and §3.6 P=.049. Body mean changes are N+2.2±3.5SEM and NC−10.67±5.4SEM. Executed arithmetic gives NC−N=−12.87, consistent with the rounded figure. SEM×√18 gives marginal individual-change SDs14.849/22.910; their average-variance standardizer19.305 yields a standardized between-treatment change magnitude about0.667. This differs from dz using the SD of paired contrasts; no independent-groups retest was performed. Executed inferential reconstruction assumes the paper’s two-sided one-sample t test, n18, P=.049 and Δ−12.9: |t|2.12023, SEΔ6.08426, approximate95%CI−25.73666 to−0.06334mg/dL. This is not a reported paper CI and depends on rounded inputs, denominator and test assumptions. P-rounding sensitivity is retained. No participant-data refit, new meta-analysis, mg/dL-to-mmol/L conversion or baseline-percentage conversion was performed. [S1 §2.7/§3.6/Fig5B; S12–S13; clinical/*.json, receipts/*_receipt.json]
Discrepancies, counterevidence and trial families
Visual comparison identified inconsistencies between Table1sequence/overall LDL baselines, abstract/table sex counts, abstract/body LDL dispersion and the Fig5B asterisk versus within-NC P=.06. Both values, locations and adoption boundaries are disclosed rather than silently correcting the source. Agreement of the main LDL contrast between text and figure does not remove these reliability limitations. The2008review was positive; the overall2016review and2021T2Dreview were nonsignificant. Different interventions, populations and times are not forced into one identical-confirmatory R0/RX set. Fotherby2000 and Gokce1999 are families shared by the meta-analysis and existing3017/3018respectively. Meta-analyses, included trials and both crossover periods are not added as independent people. The2025dialysis and2026C/Ereviews were identified in the recency search but not transferred to a four-week C-only effect in general high-LDL adults. [S1–S6; audit/pre_submission_audit.json]
Efficacy grade, numeric anchor and clinical importance
The profile submitted to the unchanged supplied calculator for this new verdict is B/S/R1/I2/E+/C0/B2. The surrogate, bias and failed-principal/positive-secondary flag impose a C ceiling. The separate original numeric-anchor table assigns two strengths(I2,E+)→C54.54is not an output of the letter-grade function. Although numerically equal to097’s C54, the axes differ and this value derives independently from the present clinical input/calculation. Without a verified between-group MCID, rubric case28’s statistical-size convention is used; clinically important LDL benefit is not declared established. Magnitude about0.667 is a medium-size classification only, not paired dz≈0.500. C54applies to this short-term secondary signal in a selected population, not every C formulation, statin combination or lifelong effect. [Supplied rubric cases28/31/43/44/45 and numeric anchors; receipts/calculator_* and final_adoption_receipt.json]
Safety: Caution
Fig2records one GI-related withdrawal among10N-first participants and four among13NC-first participants(twoGI, onehighBP, one lost to follow-up). These are sequence/first-period withdrawal records, not all-adverse-event incidence over both periods. They are shown alongside the paper’s statement of no severe adverse effects; missing reports are not changed to zero events or established safety. The small sample and shared beetroot juice prevent attribution of a C-only causal risk. NIH ODS describes GI effects of excessiveC and cautions in certain renal/iron-overload settings; the adultUL is2000mg/day from total food plus supplements. The UL is not personal prescribing or an unconditional safe dose. Observations about antioxidant combinations and HDL response to simvastatin+niacin are not expanded into blockade of all statins’ LDL effects. Long-term, pregnancy, pediatric, renal and co-medication safety are separate questions; these results do not justify stopping or replacing prescribed therapy. [S1 Fig2/§3.1; S7 safety/interactions]
Search, access, current value and revision conditions
On2026-09-18, the supplied index/originals were checked first, followed by web queries for C/ascorbic acid, LDL/hypercholesterolemia, randomized/placebo, Korean terms, DOIcorrection/retraction and MCID. PubMed, publisher/author repositories, registry and ODS pages were opened. Some broad engine queries returned irrelevant results; direct DOI/PMID access supplemented them. This is not claimed as a completed formal multidatabase systematic search. Full texts, abstracts, institutional metadata and page-shell-only access are distinguished. RegistryAPI, finalPDF/supplement and some primary-trial access attempts failed. Gaps are completed as null with reasons; clinical_todo=[]. Revision triggers include source correction/final-version access, covariance/reportedCI/ITT/multiplicity data, independent same-condition trials, validated clinical thresholds or new safety warnings. These are not a pending clinical-research assignment for the recipient. [sources.json; audit/search_access_log.json]
Classification, display and editorial review
Classification is kindS, existing canonical ingredientvitamin-c, categoryheart and tag비타민C. New siteID, slug, URL, semantic code and first-publication date remain null because none is reserved. Actual delivered display paths are ko/en.body_markdown in verdicts/TASK-1058.json and identical publication.ko/en.md files. No server page/list was newly verified or published. what_ads is null because advertising was not systematically collected; product_facts contains study-product fact sentences only. editorial_review1.0 is same-assistant self-verification, independent=false. Document qualityA assesses source traceability, boundaries, uncertainty, bilingual text and format; it is not efficacyA, error-free certification, independent review or journal certification. Initial corrections=[]; pre-submission discrepancy audit is separate. Incoming recipientFULL4/5 is not advanced toFULL5/5; task99is not started.
Seven content assessments
Directness
There is a direct four-week LDL contrast in untreated adults with high LDL, but only with shared beetroot juice. C-monotherapy reviews remain separate.
Denominators/design
23randomized,18completers and16RHI observations are distinguished;18crossover participants are not counted as36.
Numbers/arithmetic
BodySEM, plotted between-treatment contrast and P were compared; reported and reconstructed CIs are distinguished. No unit conversion or arbitrary baseline percentage calculation was made.
Bias/registration
Completer analysis, differential attrition, multiplicity, nonsignificant principalRHI/secondaryLDL and unverified registration are disclosed.
Counterevidence/families
Positive2008 and nonsignificant2016/T2D review findings are presented without pooling different diseases, cointerventions or times.
Safety/independence
ActualGI/high-BP withdrawals are separated from general safety, and public funding from unverified product donation.
Text/scope
Full bilingual text, seven axis reasons,12facets and unknown reasons share the same structure. Self-assessed documentA is distinct from efficacyC54, safetyCaution and external peer review.
Seven axis rationales and flags
| Axis | Value | Reason |
|---|---|---|
| claim_type | B | This is a clinical efficacy question about human LDL-C change, not a physical/chemical fact. |
| endpoint | S | LDL-C is a surrogate. This trial does not establish event prevention, mortality benefit or drug replacement, imposing a C ceiling. |
| replication | R1 | There is one direct trial of the same high-LDL, shared-beetroot, four-week comparison. Mixed results in other populations or C-monotherapy reviews do not establish R2 replication or automatic R0 conflict. R1 denotes the single direct trial here, not certification of a prospectively registered confirmatory study. |
| independence | I2 | University, scholarship and NIH support plus a no-conflict declaration were verified for the pivotal trial. Uncertainty about product donation is retained separately. |
| effect | E+ | No validated between-group MCID was identified, so rubric case28 tier2 was applied. The between-treatment change contrast standardized by the average marginal variance of individual period changes (body SEM, n18) has magnitude about0.667, conventionally medium. This does not establish clinically important benefit. Paired dz≈0.500 was not compared with Cohen thresholds. |
| precision | C0 | The approximate95%CI reconstructed from reported P, n and the plotted contrast (−25.74 to −0.06 mg/dL) allows a very small to a larger decrease. It is not an exact reported CI or proof excluding a clinical threshold, so C1 is not used. |
| bias | B2 | Only18 of23 randomized people were analyzed, with differential sequence attrition (1 vs4); multiplicity correction and registry-plan agreement are unverified for multiple secondary/exploratory comparisons. LDL is a positive secondary outcome alongside a nonsignificant paper-defined principal RHI outcome. Reporting gaps are distinguished from proven procedural failures. |
**primary_failed_secondary_positive**: Based on nonsignificant paper-defined principal RHI (P=.99) and positive secondary LDL. Official registered-primary agreement is unverified.
**big_hard_rct**: This small surrogate-endpoint trial is not a large hard-endpoint RCT.
**coprimary_split**: No co-primary framework was established in the paper; the partial co-primary success flag is not invoked.
12 facets — actual boundaries
| Facet | Value |
|---|---|
| kind | S |
| canonical_entity | Vitamin C (existing canonical code vitamin-c) |
| source_part | Purified supplemental nutrient; source substrate/manufacturing process unreported. Not assigned a botanical plant part. |
| formulation | Two vitamin-C capsules, total1000 mg; exact salt/molecular form/batch unverified. An add-on tested with shared70mL concentrated beetroot juice; not interchangeable with C monotherapy or a fixed combination product. |
| route | Oral; intravenous/topical excluded. |
| dose | Selected trial: C1000 mg/day, shared70mL beetroot juice (reported nitrate400–450mg); C/placebo one hour after juice. Study conditions, not personal dosing advice. |
| duration | Four weeks per intervention, with14-day washout. The4–24-week durations of another meta-analysis are not pooled as a single four-week result. |
| population | Nonsmokers aged50–70, LDL>130 mg/dL, RHI≤2, BMI18.5–34.9; no lipid-lowering therapy. Diabetes and major cardiovascular/renal/hepatic conditions excluded. Deficiency status not classified. |
| claim | Effect of C on LDL-C in adults with elevated LDL; the fixed-time direct contrast is limited to add-on C with shared beetroot juice. C-monotherapy evidence is a separate layer. |
| primary_endpoint | Within-person between-condition contrast of fasting calculated LDL-C changes over each four-week period (NC−N), mg/dL. Selected page endpoint, not verified registered primary; LDL was secondary in the paper. |
| comparator | Identical beetroot juice plus matching corn-starch placebo versus identical beetroot juice plus C. Not a comparison with C alone without juice, statins or multinutrient supplements. |
| duplicate_key | S|vitamin-c|oral|LDL-C|adults-high-LDL|no-completed-identical-claim-in-supplied-snapshot |
All unresolved, unperformed and inapplicable fields
| ID / field | Value / status | Reason / location |
|---|---|---|
| U01 vitamin_c_exact_salt_and_stereochemistry | null / not_reported | The report names Nature Made vitamin C 1000 mg, but does not establish the salt, stereochemistry or independent chemical assay. [S1; §2.6] |
| U02 vitamin_c_batch_purity_excipient | null / not_reported | Batch, purity, full excipients and assayed content are not provided. [S1; §2.6] |
| U03 manufacturing_origin | null / not_reported | Manufacturing substrate, country and process cannot be established from the paper. [S1; §2.6] |
| U04 deficiency_diagnosis | null / not_reported | A plasma-C summary is reported, but no prespecified deficiency definition or deficiency-stratified LDL effect is supplied. Participants were not reclassified as deficient or replete. [S1; Table 1] |
| U05 quantitative_total_dietary_c | null / not_reported | High-C food restrictions and recalls are described, but actual total intake and period-specific adequacy proportions are not provided. [S1; §2.3;§3.1] |
| U06 true_total_baseline_ldl | null / conflicting | Table 1 lists sequence LDL values 135.3 and 167.9 (nine each), whose arithmetic mean is 151.6, but reports 160.6 overall. The correct source value is unresolved. [S1; Table 1, PDF p5] |
| U07 verified_sex_counts | null / conflicting | The abstract gives 11 men/7 women, whereas Table 1 gives 7 men (39%). Neither was silently corrected. [S1; Abstract vs Table 1] |
| U08 abstract_ldl_dispersion_type | null / conflicting | Abstract dispersions ±2/±23 differ from body values ±3.5/±5.4. Calculations use only the body values, explicitly described as mean±SEM. [S1; Abstract;§2.7;§3.6] |
| U09 within_nc_ldl_significance | null / conflicting | The Figure 5B asterisk conflicts with within-NC P=.06 in the text. Within-period significance was not adopted or substituted for between-treatment P=.049. [S1; §3.6/Fig 5B] |
| U10 reported_between_ldl_ci | null / not_reported | A between-treatment 95% CI is not directly reported. The separately calculated −25.74 to −0.06 mg/dL interval is an approximation reconstructed from reported P, n and the plotted contrast. [S1; §3.6/Fig 5B] |
| U11 exact_unrounded_delta_and_p | null / not_reported | Raw data, unrounded contrast and exact P are unavailable; only rounded published values were used. [S1; §3.6/Fig 5B] |
| U12 paired_change_correlation | null / not_reported | Within-person correlation/covariance of the two period changes is not directly supplied. No assumed correlation was used to manufacture an independent-groups test. [S1; §2.7] |
| U13 ldl_assay_quality_control | null / not_reported | LDL was calculated by Friedewald; assay batches, calibration, precision and high-TG exclusion rules were not obtained. [S1; §2.5] |
| U14 individual_friedewald_inputs | null / not_reported | Individual TC/HDL/TG values and their raw input units are unavailable; participant LDL values were not recalculated. [S1; §2.5] |
| U15 directly_measured_ldl | null / not_applicable | The selected trial evaluates calculated LDL-C, not directly measured LDL. [S1; §2.5] |
| U16 statin_treated_effect | null / not_applicable | Lipid-lowering therapy was an exclusion. This does not estimate a statin add-on effect or the effects of drug reduction or withdrawal. [S1; §2.1] |
| U17 specific_other_medications_stability | null / not_reported | BP medication use is reported in six completers, but names, dose stability and period-specific changes are insufficiently detailed. [S1; Table 1/§2.3] |
| U18 diet_exercise_weight_period_changes | null / not_reported | Diet was described as not significantly changed without detailed data; quantitative exercise/weight changes and LDL adjustment for them are not supplied. [S1; §3.1] |
| U19 vitamin_timing_adherence | null / not_reported | Amount-based adherence is reported, but daily adherence to taking C exactly one hour after beetroot juice is not verified. [S1; §2.6/§3.1] |
| U20 itt_ldl_effect_and_imputation | null / not_reported | LDL analysis uses 18 completers; an ITT effect for all 23 randomized participants and imputed results are not supplied. [S1; Fig 2/§2.7] |
| U21 withdrawn_participant_ldl | null / not_reported | Final LDL values for the five withdrawals and an attrition sensitivity analysis were not obtained. [S1; Fig 2] |
| U22 multiplicity_adjustment | null / not_reported | Multiplicity correction for P=.049 among multiple lipid, vascular and subgroup comparisons is not reported. [S1; §2.7/§4] |
| U23 registered_primary_endpoint | null / inaccessible | The paper treats RHI as the principal outcome, but official registry content/history was unavailable; agreement with the registered primary outcome is not claimed. [S8; Official page/API] |
| U24 registration_timing | null / inaccessible | The official registration date and prospective status were not verified. Dates from third-party mirrors were not adopted as confirmed values. [S8; Official page/API] |
| U25 ldl_prespecified_analysis_plan | null / inaccessible | A prespecified LDL analysis plan, selected time point and hierarchical testing strategy could not be checked against registration history. [S8; Registry/supplement] |
| U26 separate_period_order_adjusted_ldl_effect | null / not_reported | Washout and a carryover test P=.78 are reported, but a separate period/order-adjusted LDL estimate and CI are not given. [S1; §2.7/§3.6] |
| U27 absence_of_carryover_proven | null / not_applicable | A nonsignificant carryover test is not equivalence proof that carryover is exactly zero. [S1; §3.6] |
| U28 ldl_between_group_mcid | null / not_identified_in_search | No validated between-group LDL clinical threshold was identified in the limited MCID search or paper. Individual LDL targets or percentage-reduction goals were not substituted. [S1/S12/S13; Search and statistical-size classification] |
| U29 clinical_events_and_drug_replacement | null / not_applicable | The selected result does not test myocardial infarction, stroke, mortality or replacement of prescribed therapy. [S1; Outcome scope] |
| U30 vitamin_c_alone_same_population_time | null / not_reported | The primary contrast includes shared beetroot juice. A four-week C-monotherapy effect in the same high-LDL population is not isolated by this trial. [S1; §2.6] |
| U31 independent_exact_replication | null / not_identified_in_search | An independent confirmatory replication of the same population, beetroot background, dose and four-week LDL contrast was not identified. [S1/S2/S3; Trial-family review] |
| U32 interaction_or_synergy_effect | null / not_applicable | Without a C-only arm lacking beetroot juice, a C×nitrate interaction or synergy effect cannot be estimated. [S1; Design] |
| U33 all_adverse_event_denominators | null / not_reported | Withdrawal reasons are available, but a participant-level table of all adverse events and exposure time across both periods is not. Missing reports were not treated as zero events. [S1; Fig 2/§3.1] |
| U34 vitamin_c_specific_harm_causality | null / not_reported | Both conditions included beetroot juice and the sample is small; GI symptoms/high-BP withdrawal do not establish C-only causality or population incidence. [S1; Fig 2] |
| U35 long_term_pregnancy_pediatric_renal_safety | null / not_applicable | Four-week findings in adults aged 50–70 excluding major diseases cannot establish long-term, pregnancy, pediatric or renal-disease safety. [S1/S7; Eligibility/safety] |
| U36 product_donation_and_batch_independence | null / not_reported | Public/university support and a no-conflict declaration were confirmed, but product donation and batch verification were not established. [S1/S14; Funding/COI] |
| U37 final_paginated_paper_and_supplement | null / inaccessible | The accessed PDF is an article-in-press version. The final paginated article and supplement were not obtained to reconcile every discrepancy. [S1; Version] |
| U38 definitive_correction_retraction_clearance | null / not_identified_in_search | The DOI-specific search did not identify a correction/retraction notice for this article, but this is not exhaustive clearance of its publication history. [S1; DOI-specific search] |
| U39 mcrae_individual_trial_fulltext_verification | null / not_searched | Every primary trial within the meta-analysis was not re-opened in full. Existing3017/3018 identifiers/families were reused, and new LDL extraction is labelled as meta-level. [S2; Tables 1/3] |
| U40 mcrae_all_high_ldl_status | null / not_reported | The meta-analysis eligibility criterion was total cholesterol >200; it does not establish LDL >130 for every participant. [S2; Eligibility/Table 1] |
| U41 ashor_overall_ldl_numeric_effect | null / inaccessible | The abstract confirms an overall nonsignificant conclusion, but the full table with the overall LDL estimate, CI and denominator was not obtained. [S3; Abstract/full text unavailable] |
| U42 cross_review_overlap_unique_total | null / not_reported | Participants from multiple meta-analyses and primary trials were not added into an independent total. A complete cross-review overlap matrix is unresolved. [S2/S3/S4/S5/S6; Study-family mapping] |
| U43 dialysis_meta_ldl_unit_subset | null / not_reported | The dialysis abstract reports WMD −24.81 without a fully specified LDL subset denominator and explicit unit. It was not pooled with mg/dL values from other populations. [S5; Abstract] |
| U44 2026_c_only_ldl_value | null / inaccessible | The 2026 T2D review abstract covering C/E/C+E does not provide an extractable C-only LDL estimate and CI. [S6; Abstract] |
| U45 cerna_18month_numeric_ldl_difference | null / not_reported | The abstract describes a reduction but lacks a numeric between-group LDL effect, CI, registration and missing-data details; it was not selected as primary. [S9; Abstract] |
| U46 cerna_meta_report_overlap | null / conflicting | The meta-analysis describes 24-week Cerna1992 data, whereas the accessed abstract describes 140 people over 18 months. Their report/subset relationship was not resolved, so they were not added as independent participants. [S2/S9; Table 1 vs abstract] |
| U47 healthy_trial_exact_c_ldl_estimate | null / not_reported | The healthy older-adult four-arm abstract lacks the exact C-only LDL contrast, CI and established high-LDL baseline status. [S10; Abstract] |
| U48 combination_trial_isolated_c_effect | null / not_applicable | Differences involving monacolin K, arginine and CoQ10 prevent isolation of a C-specific incremental effect. [S11; Interventions] |
| U49 what_ads | null / not_searched | This task addressed clinical LDL evidence; advertising claims were not systematically collected. This does not mean no advertising exists. [INPUT; Contract] |
| U50 site_id_slug_url_semantic_code_first_publication | null / not_assigned | No site reservation, connection or deployment occurred; ID, slug, URL, semantic code and first publication remain null. The TASK number is not a site ID. [INPUT; Delivery scope] |
| U51 representative_list_live_url | null / not_searched | The existing vitamin-c codebook entry and tag are linked, but a live listing URL/placement was not verified. The097 HTTP receipt concerns historical BP material. [INPUT; Codebook/097 history] |
| U52 independent_external_peer_review | null / not_performed | This is self-verification by the same assistant. Independent external review, journal certification and recipient FULL5/5 were not performed. [INPUT; Workflow] |
| U53 review_funding_and_included_trial_product_funding | null / not_reported | Funding and product provision for S2 and every included primary trial were not fully established. S4’s lack of a specific review grant does not establish independence of its included trials; I2 rests only on verified S1 funding. [S2/S3/S4/S5/S6; Funding scope] |
| U54 individual_trial_ldl_subgroup_interactions | null / not_reported | Sufficient source data are unavailable for LDL interactions by age, sex, baseline LDL, deficiency or medication. Significance in one subgroup and not another is not treated as an interaction test. [S1/S2/S3; Subgroup scope] |
Sources and actual access levels
**S1** — Basaqr R, Skleres M, Jayswal R, Thomas DT. Clin Nutr. 2021;40(4):1851–1860. Online 2020-10-14.
https://pubmed.ncbi.nlm.nih.gov/33115598/
DOI: 10.1016/j.clnu.2020.10.012. PMID: 33115598. Access: full_text_author_uploaded_article_in_press_pdf_and_pubmed_abstract. Location: §2.1 eligibility; §2.2–2.3 randomization/protocol; §2.5 assay; §2.6 products; §2.7 statistics; Fig 2 PDF p4; Table 1 PDF p5; §3.6 PDF p7; Fig 5B PDF p8; funding/COI PDF p9.
Full text accessed: https://www.researchgate.net/publication/346212679_The_effect_of_dietary_nitrate_and_vitamin_C_on_endothelial_function_oxidative_stress_and_blood_lipids_in_untreated_hypercholesterolemic_subjects_A_randomized_double-blind_crossover_study/fulltext/60a3c668299bf1d21d716331/The-effect-of-dietary-nitrate-and-vitamin-C-on-endothelial-function-oxidative-stress-and-blood-lipids-in-untreated-hypercholesterolemic-subjects-A-randomized-double-blind-crossover-study.pdf
**S2** — McRae MP. J Chiropr Med. 2008;7(2):48–58.
https://pubmed.ncbi.nlm.nih.gov/19674720/
DOI: 10.1016/j.jcme.2008.01.002. PMID: 19674720. Access: full_text_author_upload_html_and_official_abstract. Location: Methods eligibility and variance assumptions; Results LDL participants; Table 1 and Table 3 text; LDL pooled result.
Full text accessed: https://www.researchgate.net/publication/26736132_Vitamin_C_supplementation_lowers_serum_low-density_lipoprotein_cholesterol_and_triglycerides_A_meta-analysis_of_13_randomized_controlled_trials
**S3** — Ashor AW et al. Clin Nutr. 2016.
https://pubmed.ncbi.nlm.nih.gov/26164552/
DOI: 10.1016/j.clnu.2015.05.021. PMID: 26164552. Access: official_abstract. Location: Abstract Methods/Results/Conclusions.
**S4** — Tareke AA, Hadgu AA. Diabetol Metab Syndr. 2021;13:24.
https://link.springer.com/article/10.1186/s13098-021-00640-9
DOI: 10.1186/s13098-021-00640-9. Access: full_text_html. Location: Methods eligibility; LDL-C meta-analysis result; Funding/competing interests.
**S5** — de Oliveira IM et al. Nutr Res. 2025;139:124–135. Online 2024-09-21.
https://pubmed.ncbi.nlm.nih.gov/40532258/
DOI: 10.1016/j.nutres.2024.09.014. PMID: 40532258. Access: official_abstract. Location: Abstract.
**S6** — Aragón-Vela J, Huertas JR, Casuso RP. Nutr Rev. 2026;84(2):235–245.
https://www.uloyola.es/en/research-transfer/publications/effects-of-vitamin-c-and-or-e-supplementation-on-glycemic-control-and-cardiovascular-risk-factors-in-type-2-diabetes-a-systematic-review-and-subgroup-meta-analysis-review
DOI: 10.1093/nutrit/nuaf133. Access: author_institution_abstract_and_publisher_issue_metadata. Location: Abstract; publication date 2026-02-01.
**S7** — NIH Office of Dietary Supplements. Vitamin C: Fact Sheet for Health Professionals.
https://ods.od.nih.gov/factsheets/VitaminC-HealthProfessional/
Access: full_text_html. Location: Health risks from excessive vitamin C; Interactions with medications; UL table.
**S8** — trial_registry
https://clinicaltrials.gov/study/NCT04283630
Access: page_shell_only_api_failed. Location: .
**S9** — Cerná O, Ramacsay L, Ginter E. Cor Vasa. 1992;34(3):246–254.
https://pubmed.ncbi.nlm.nih.gov/1306421/
PMID: 1306421. Access: official_abstract. Location: Abstract.
**S10** — The salutary effects of antioxidant vitamins on the plasma lipids of healthy middle aged-to-elderly individuals: a randomized, double-blind, placebo-controlled study. 2003.
https://pubmed.ncbi.nlm.nih.gov/12841306/
PMID: 12841306. Access: official_abstract. Location: Methods/Results.
**S11** — LDL-cholesterol lowering effect of a new dietary supplement: an open label, controlled, randomized, cross-over clinical trial in patients with mild-to-moderate hypercholesterolemia. 2018.
https://pmc.ncbi.nlm.nih.gov/articles/PMC5968477/
Access: primary_article_abstract_and_methods_excerpts. Location: Abstract/Methods.
**S12** — SciPy documentation: scipy.stats.t.
https://docs.scipy.org/doc/scipy/reference/generated/scipy.stats.t.html
Access: official_documentation. Location: ppf / Student t distribution.
**S13** — Lakens D. Calculating and reporting effect sizes to facilitate cumulative science. Front Psychol. 2013;4:863.
https://www.frontiersin.org/journals/psychology/articles/10.3389/fpsyg.2013.00863/full
DOI: 10.3389/fpsyg.2013.00863. Access: full_text_html. Location: Within-subject effect-size standardization.
**S14** — author_institution_repository
https://uknowledge.uky.edu/atcn_facpub/4/
Access: full_repository_record. Location: Funding information; publication date; DOI.
Why this is classified as C (54)
The profile submitted to the unchanged supplied calculator for this new verdict is B/S/R1/I2/E+/C0/B2. The surrogate, bias and failed-principal/positive-secondary flag impose a C ceiling. The separate original numeric-anchor table assigns two strengths(I2,E+)→C54.54is not an output of the letter-grade function. Although numerically equal to097’s C54, the axes differ and this value derives independently from the present clinical input/calculation. Without a verified between-group MCID, rubric case28’s statistical-size convention is used; clinically important LDL benefit is not declared established. Magnitude about0.667 is a medium-size classification only, not paired dz≈0.500. C54applies to this short-term secondary signal in a selected population, not every C formulation, statin combination or lifelong effect. [Supplied rubric cases28/31/43/44/45 and numeric anchors; receipts/calculator_* and final_adoption_receipt.json]
Counterpoint. Visual comparison identified inconsistencies between Table1sequence/overall LDL baselines, abstract/table sex counts, abstract/body LDL dispersion and the Fig5B asterisk versus within-NC P=.06. Both values, locations and adoption boundaries are disclosed rather than silently correcting the source. Agreement of the main LDL contrast between text and figure does not remove these reliability limitations. The2008review was positive; the overall2016review and2021T2Dreview were nonsignificant. Different interventions, populations and times are not forced into one identical-confirmatory R0/RX set. Fotherby2000 and Gokce1999 are families shared by the meta-analysis and existing3017/3018respectively. Meta-analyses, included trials and both crossover periods are not added as independent people. The2025dialysis and2026C/Ereviews were identified in the recency search but not transferred to a four-week C-only effect in general high-LDL adults. [S1–S6; audit/pre_submission_audit.json]
Rejudgment record. The profile submitted to the unchanged supplied calculator for this new verdict is B/S/R1/I2/E+/C0/B2. The surrogate, bias and failed-principal/positive-secondary flag impose a C ceiling. The separate original numeric-anchor table assigns two strengths(I2,E+)→C54.54is not an output of the letter-grade function. Although numerically equal to097’s C54, the axes differ and this value derives independently from the present clinical input/calculation. Without a verified between-group MCID, rubric case28’s statistical-size convention is used; clinically important LDL benefit is not declared established. Magnitude about0.667 is a medium-size classification only, not paired dz≈0.500. C54applies to this short-term secondary signal in a selected population, not every C formulation, statin combination or lifelong effect. [Supplied rubric cases28/31/43/44/45 and numeric anchors; receipts/calculator_* and final_adoption_receipt.json]
Seven original axes · statistical size is not clinical importance
| claim_type | B | This is a clinical efficacy question about human LDL-C change, not a physical/chemical fact. |
| endpoint | S | LDL-C is a surrogate. This trial does not establish event prevention, mortality benefit or drug replacement, imposing a C ceiling. |
| replication | R1 | There is one direct trial of the same high-LDL, shared-beetroot, four-week comparison. Mixed results in other populations or C-monotherapy reviews do not establish R2 replication or automatic R0 conflict. R1 denotes the single direct trial here, not certification of a prospectively registered confirmatory study. |
| independence | I2 | University, scholarship and NIH support plus a no-conflict declaration were verified for the pivotal trial. Uncertainty about product donation is retained separately. |
| effect | E+ | No validated between-group MCID was identified, so rubric case28 tier2 was applied. The between-treatment change contrast standardized by the average marginal variance of individual period changes (body SEM, n18) has magnitude about0.667, conventionally medium. This does not establish clinically important benefit. Paired dz≈0.500 was not compared with Cohen thresholds. |
| precision | C0 | The approximate95%CI reconstructed from reported P, n and the plotted contrast (−25.74 to −0.06 mg/dL) allows a very small to a larger decrease. It is not an exact reported CI or proof excluding a clinical threshold, so C1 is not used. |
| bias | B2 | Only18 of23 randomized people were analyzed, with differential sequence attrition (1 vs4); multiplicity correction and registry-plan agreement are unverified for multiple secondary/exploratory comparisons. LDL is a positive secondary outcome alongside a nonsignificant paper-defined principal RHI outcome. Reporting gaps are distinguished from proven procedural failures. |
primary_failed_secondary_positive · Based on nonsignificant paper-defined principal RHI (P=.99) and positive secondary LDL. Official registered-primary agreement is unverified.
big_hard_rct · This small surrogate-endpoint trial is not a large hard-endpoint RCT.
coprimary_split · No co-primary framework was established in the paper; the partial co-primary success flag is not invoked.
Review performed and remaining limitations
The report names Nature Made vitamin C 1000 mg, but does not establish the salt, stereochemistry or independent chemical assay. Batch, purity, full excipients and assayed content are not provided. Manufacturing substrate, country and process cannot be established from the paper. A plasma-C summary is reported, but no prespecified deficiency definition or deficiency-stratified LDL effect is supplied. Participants were not reclassified as deficient or replete. High-C food restrictions and recalls are described, but actual total intake and period-specific adequacy proportions are not provided. Table 1 lists sequence LDL values 135.3 and 167.9 (nine each), whose arithmetic mean is 151.6, but reports 160.6 overall. The correct source value is unresolved. The abstract gives 11 men/7 women, whereas Table 1 gives 7 men (39%). Neither was silently corrected. Abstract dispersions ±2/±23 differ from body values ±3.5/±5.4. Calculations use only the body values, explicitly described as mean±SEM. The Figure 5B asterisk conflicts with within-NC P=.06 in the text. Within-period significance was not adopted or substituted for between-treatment P=.049. A between-treatment 95% CI is not directly reported. The separately calculated −25.74 to −0.06 mg/dL interval is an approximation reconstructed from reported P, n and the plotted contrast. Raw data, unrounded contrast and exact P are unavailable; only rounded published values were used. Within-person correlation/covariance of the two period changes is not directly supplied. No assumed correlation was used to manufacture an independent-groups test. LDL was calculated by Friedewald; assay batches, calibration, precision and high-TG exclusion rules were not obtained. Individual TC/HDL/TG values and their raw input units are unavailable; participant LDL values were not recalculated. The selected trial evaluates calculated LDL-C, not directly measured LDL. Lipid-lowering therapy was an exclusion. This does not estimate a statin add-on effect or the effects of drug reduction or withdrawal. BP medication use is reported in six completers, but names, dose stability and period-specific changes are insufficiently detailed. Diet was described as not significantly changed without detailed data; quantitative exercise/weight changes and LDL adjustment for them are not supplied. Amount-based adherence is reported, but daily adherence to taking C exactly one hour after beetroot juice is not verified. LDL analysis uses 18 completers; an ITT effect for all 23 randomized participants and imputed results are not supplied. Final LDL values for the five withdrawals and an attrition sensitivity analysis were not obtained. Multiplicity correction for P=.049 among multiple lipid, vascular and subgroup comparisons is not reported. The paper treats RHI as the principal outcome, but official registry content/history was unavailable; agreement with the registered primary outcome is not claimed. The official registration date and prospective status were not verified. Dates from third-party mirrors were not adopted as confirmed values. A prespecified LDL analysis plan, selected time point and hierarchical testing strategy could not be checked against registration history. Washout and a carryover test P=.78 are reported, but a separate period/order-adjusted LDL estimate and CI are not given. A nonsignificant carryover test is not equivalence proof that carryover is exactly zero. No validated between-group LDL clinical threshold was identified in the limited MCID search or paper. Individual LDL targets or percentage-reduction goals were not substituted. The selected result does not test myocardial infarction, stroke, mortality or replacement of prescribed therapy. The primary contrast includes shared beetroot juice. A four-week C-monotherapy effect in the same high-LDL population is not isolated by this trial. An independent confirmatory replication of the same population, beetroot background, dose and four-week LDL contrast was not identified. Without a C-only arm lacking beetroot juice, a C×nitrate interaction or synergy effect cannot be estimated. Withdrawal reasons are available, but a participant-level table of all adverse events and exposure time across both periods is not. Missing reports were not treated as zero events. Both conditions included beetroot juice and the sample is small; GI symptoms/high-BP withdrawal do not establish C-only causality or population incidence. Four-week findings in adults aged 50–70 excluding major diseases cannot establish long-term, pregnancy, pediatric or renal-disease safety. Public/university support and a no-conflict declaration were confirmed, but product donation and batch verification were not established. The accessed PDF is an article-in-press version. The final paginated article and supplement were not obtained to reconcile every discrepancy. The DOI-specific search did not identify a correction/retraction notice for this article, but this is not exhaustive clearance of its publication history. Every primary trial within the meta-analysis was not re-opened in full. Existing3017/3018 identifiers/families were reused, and new LDL extraction is labelled as meta-level. The meta-analysis eligibility criterion was total cholesterol >200; it does not establish LDL >130 for every participant. The abstract confirms an overall nonsignificant conclusion, but the full table with the overall LDL estimate, CI and denominator was not obtained. Participants from multiple meta-analyses and primary trials were not added into an independent total. A complete cross-review overlap matrix is unresolved. The dialysis abstract reports WMD −24.81 without a fully specified LDL subset denominator and explicit unit. It was not pooled with mg/dL values from other populations. The 2026 T2D review abstract covering C/E/C+E does not provide an extractable C-only LDL estimate and CI. The abstract describes a reduction but lacks a numeric between-group LDL effect, CI, registration and missing-data details; it was not selected as primary. The meta-analysis describes 24-week Cerna1992 data, whereas the accessed abstract describes 140 people over 18 months. Their report/subset relationship was not resolved, so they were not added as independent participants. The healthy older-adult four-arm abstract lacks the exact C-only LDL contrast, CI and established high-LDL baseline status. Differences involving monacolin K, arginine and CoQ10 prevent isolation of a C-specific incremental effect. This task addressed clinical LDL evidence; advertising claims were not systematically collected. This does not mean no advertising exists. No site reservation, connection or deployment occurred; ID, slug, URL, semantic code and first publication remain null. The TASK number is not a site ID. The existing vitamin-c codebook entry and tag are linked, but a live listing URL/placement was not verified. The097 HTTP receipt concerns historical BP material. This is self-verification by the same assistant. Independent external review, journal certification and recipient FULL5/5 were not performed. Funding and product provision for S2 and every included primary trial were not fully established. S4’s lack of a specific review grant does not establish independence of its included trials; I2 rests only on verified S1 funding. Sufficient source data are unavailable for LDL interactions by age, sex, baseline LDL, deficiency or medication. Significance in one subgroup and not another is not treated as an interaction test.
Evidence Table
| Source | Design | Population / denominator | Exposure / time | LDL result | Role / limitation |
|---|---|---|---|---|---|
| S1 | Randomized double-blind crossover | 23 randomized (sequences10/13),18 completed (9/9); the same18 received both conditions. LDL n18, RHI n16. | Shared beetroot juice+C1000mg versus shared juice+placebo; four weeks each/14-day washout | Reported contrast of changes−12.9mg/dL (Fig5B), P=.049. Body mean changes: N+2.2±3.5SEM, NC−10.67±5.4SEM. No directly reported CI; present approximate CI−25.74 to−0.06. | Primary page endpoint/four weeks. Secondary LDL, completer analysis, multiplicity and reporting discrepancies. Not C monotherapy. |
| S2 | LDL11 comparisons within a13-RCT review | LDL549 unique individuals; C328/control310 include crossover participation and are not638 unique people. | C500–2000mg/day, placebo,4–24weeks (median10); total-cholesterol>200 eligibility | Pooled net change−7.9mg/dL,95%CI−12.3 to−3.5. Paper P=.000 is rounded reporting, not exact zero. | C-monotherapy layer. Not every participant had high LDL; change correlation.5/equal variance are the review authors’ assumptions. Included trials are not added again. |
| S3 | Adult-RCT systematic review/meta-analysis | Overall LDL denominator/numeric full table unavailable | At least two weeks; searches through August2014; varied trial conditions | Abstract: overall lipid effects nonsignificant. Subgroup signals are not generalized to the overall effect. | Counterevidence context, not direct repeated refutation of the same four-week beetroot contrast. Nonsignificance is not equivalence. |
| S4 | T2D RCT meta-analysis | Type2 diabetes; the LDL subset denominator is not equated with the number of all articles | C for at least two weeks, placebo/no treatment; crossover/active-control/combinations excluded | LDL WMD+2.73mg/dL,95%CI−1.72 to7.17,P=.229. | Kept separate for diabetes. Not exact zero or drug equivalence. |
| S5 | Hemodialysis RCT+nonrandomized-study review | 549 across12 studies is not the LDL-subset denominator | Oral4–52weeks,51.4–1000mg/day; LDL analysis reported for≥12weeks | Decrease WMD−24.81,CI−44.28 to−5.33,P=.008,I²79.1%; explicit unit/LDL-subset denominator unverified in the abstract. | 2025 publication (2024 online), renal special population. No invented unit or extension to general adults. |
| S6 | 2026 T2D C/E/C+E subgroup meta-analysis | Abstract52studies/1425 is an overall multivitamin/multi-outcome total | C/E/combination must remain distinct | C-only LDL estimate/CI absent from accessed abstract | Indirect recency layer. HDL/BP and vitaminE are not substituted for C-LDL. |
| S9 | Longer-term hyperlipidemia trial abstract | Abstract140 participants (83/57); overlap with review subset unresolved | L-ascorbic acid500mg/day,18months; sampling every six months | LDL reduction described; exact between-group contrast/CI unverified | Excluded as the numeric primary contrast; not added as independent participants. |
| S10 | Four-armRCT in healthy adults≥50, abstract | 120total, C/E/C+E/placebo; high-LDL selection unverified | 75days; exact C dose not established from this abstract | Reduction/significance described, without C-only effect/CI | Not primary because of healthy-population boundary and numeric gaps. |
| S11 | Open-label combination-product crossover | 20adults with LDL130–180mg/dL | Different monacolin-K combination products,eight weeks each/four-week washout | C-specific LDL effect not isolatable | Excluded because other ingredients including arginine differ; no attribution to C. |
Receipt — 14 References
Evidence access cutoff: 2026-09-18. Each citation states its actual access level (full-text transcription, abstract, index, or other) and remaining limitations. Bibliographic checking does not certify the study results or treatment efficacy.
Technical integration by: Codex · Evidence date: 2026-09-18 · Corrections: none
Cite this verdict
[Chamgap] Vitamin C × LDL cholesterol: four-week add-on effect with shared beetroot juice — Evidence Grade C·54. 14 cited sources checked. Source: https://chamgap.com/en/verdicts/heart/vitamin-c-add-on-beetroot-four-week-ldl-cholesterol/ · CC BY 4.0CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.
What this document does and does not do
Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.