Vitamin C and scar strength: analysis of a historical trial and implications for collagen-related pathologies

SNaP-C: Validation of a novel, selective silver nanoparticle antioxidant capacity assay for Vitamin C content in beverages

A validated silver nanoparticle assay (SNaP-C) for quantitation of Vitamin C, as ascorbic acid (AA) and total AA (TAA), was applied to 31 beverages. SNaP-C assay results (LOD of 2.2 mg/L AA) were compared to AA and TAA determined by high-performance liquid chromatography with UV/Vis (LOD = 0.4 mg/L AA), and two well-known assays. All approaches were calibrated using meta-phosphoric acid stabilized AA, where the reducing agent tris(2-carboxyethyl) phosphine hydrochloride was added to convert dehydroascorbic acid to AA for determination of TAA. Statistical comparisons of these four resulting datasets were completed. SNaP-C and HPLC were not statistically significantly different (P > 0.05) for comparison of AA and TAA (mg/L) in these samples, whereas the CUPRAC and Folin-Ciocalteu assays statistically significantly overestimated values of AA and TAA content, respectively. The SNaP-C method is a novel assay that has high specificity for AA capable of quantifying TAA with addition of TCEP.

Vitamin C - a scoping review for Nordic Nutrition Recommendations 2023

Vitamin C has multiple metabolic functions in the body, but the available information on the exact relationship between these functions and the intake necessary to maintain them is very limited. However, most attempts to objectively measure adequacy of vitamin C status, including, for example, replacement of metabolic turnover, chronic disease prevention, urinary excretion, and saturation of immune cells and body compartment, currently point toward 50 µmol/L as a reasonable target plasma concentration. As a strong correlation between body weight and vitamin C status exists, recommended intakes (RIs) for other age groups may be extrapolated from the adult RI based on weight. However, as body weights above 70 kg are becoming increasingly common - also in the Nordic region - an RI of 140 mg/day for individuals weighing 100 kg or more should be considered to compensate for the larger volume of distribution. Finally, smoking continues to be a common contributor to poor vitamin C status; therefore, it is proposed that people who smoke increase their daily vitamin C intake by 40 mg/day to compensate for the increased metabolic turnover induced by smoking.

The Forgotten Disease in the 21st Century: Scurvy Outbreak in Hawassa Central Prison, Hawassa, Sidama, Southern Ethiopia, 2023

Background

Dietary deficiencies in vitamin C lead to scurvy, an uncommon disease of nutritional deficiency in contemporary clinical practice. The inability of humans to synthesize vitamin C necessitates the regular consumption of vitamin C containing fruits, vegetables, or tablets.

Objective

To report a series of cases that came to HUCSH from May 25th up to the 18th of July, 2023, and to describe clinical features of scurvy from an observational study of on-site prison investigation.

Methods

A descriptive analysis of a case series of ten patients admitted to HUCSH between May 25th and July 18th, 2023, and on-site observational study of 67 patients over one month. A structured questionnaire was used to collect data, and SPSS version 25 was used for analysis.

Results

From the case series, all of the ten patients had either unilateral or bilateral leg swelling or pain as common compliant and all of them were male prisoners with mean age of 25.6±5.33 years and following admission, the hemoglobin value increased to 7.1±1.34 g/dL with treatment from 4.6±1.88 g/dL. From observational study of the prison, 67 cases were identified based on unilateral or bilateral leg swelling and/or pain, which was the presenting feature in the cluster of cases seen at HUCSH. The mean age was 23.57±6.4 years, and each patient got therapeutic doses of ascorbic acid 500mg PO daily using directly observed therapy and follow-up visit was after two and four weeks of ascorbic acid initiation and all patients showed significant improvement.

Conclusion

For clinicians in modern medicine, there should be a high index of suspicion for scurvy as a possible differential diagnosis when a patient presents with leg swelling in high-risk population, such as prisoners. Health-care providers in prison clinics need to be alert to such forgotten yet life-costly disease in resource constrained prison clinics.

What We Are Missing: Using Machine Learning Models to Predict Vitamin C Deficiency in Patients with Metabolic and Bariatric Surgery

PURPOSE

Vitamin C (VC) is implicated in many physiological pathways. Vitamin C deficiency (VCD) can compromise the health of patients with metabolic and bariatric surgery (patients). As symptoms of VCD are elusive and data on VCD in patients is scarce, we aim to characterize patients with measured VC levels, investigate the association of VCD with other lab abnormalities, and create predictive models of VCD using machine learning (ML).

METHODS

A retrospective chart review of patients seen from 2017 to 2021 at a tertiary care center in Northeastern USA was conducted. A 1:4 case mix of patients with VC measured to a random sample of patients without VC measured was created for comparative purposes. ML models (BayesNet and random forest) were used to create predictive models and estimate the prevalence of VCD patients.

RESULTS

Of 5946 patients reviewed, 187 (3.1%) had VC measures, and 73 (39%) of these patients had VC<23 μmol/L(VCD. When comparing patients with VCD to patients without VCD, the ML algorithms identified a higher risk of VCD in patients deficient in vitamin B1, D, calcium, potassium, iron, and blood indices. ML models reached 70% accuracy. Applied to the testing sample, a "true" VCD prevalence of ~20% was predicted, among whom ~33% had scurvy levels (VC<11 μmol/L).

CONCLUSION

Our models suggest a much higher level of patients have VCD than is reflected in the literature. This indicates a high proportion of patients remain potentially undiagnosed for VCD and are thus at risk for postoperative morbidity and mortality.

Vitamin C supplementation for diabetes management: A comprehensive narrative review

Growing evidence suggests that vitamin C supplementation may be an effective adjunct therapy in the management of people with diabetes. This paper critically reviews the current evidence on effects of vitamin C supplementation and its potential mechanisms in diabetes management. Evidence from meta-analyses of randomized controlled trials (RCTs) show favourable effects of vitamin C on glycaemic control and blood pressure that may be clinically meaningful, and mixed effects on blood lipids and endothelial function. However, evidence is mostly of low evidence certainty. Emerging evidence is promising for effects of vitamin C supplementation on some diabetes complications, particularly diabetic foot ulcers. However, there is a notable lack of robust and well-designed studies exploring effects of vitamin C as a single compound supplement on diabetes prevention and patient-important outcomes (i.e. prevention and amelioration of diabetes complications). RCTs are also required to investigate potential preventative or ameliorative effects of vitamin C on gestational diabetes outcomes. Oral vitamin C doses of 500-1000 mg per day are potentially effective, safe, and affordable for many individuals with diabetes. However, personalisation of supplementation regimens that consider factors such as vitamin C status, disease status, current glycaemic control, vitamin C intake, redox status, and genotype is important to optimize vitamin C's therapeutic effects safely. Finally, given a high prevalence of vitamin C deficiency in patients with complications, it is recommended that plasma vitamin C concentration be measured and monitored in the clinic setting.

Spontaneous haematomas and haematochezia due to vitamin C deficiency in a haemodialysis patient

A man in his 50s with dialysis-dependent end-stage renal disease, several weeks history of progressive skin bruising and acute-onset gastrointestinal bleeding presented to the emergency department following a syncopal event during routine haemodialysis owing to profound hypotension. He was found to have a severe normocytic, normochromic anaemia requiring several blood transfusions. He followed a diet lacking fruits and vegetables and stopped taking renal multivitamins. All parameters of coagulation were unremarkable, but serum vitamin C level was undetectable, supporting a diagnosis of scurvy. Although typically associated with individuals who are at risk of malnourishment, such as those with alcohol use disorder, malabsorption, and those who experience homelessness, scurvy should be considered in patients receiving renal replacement therapy as vitamin C is removed during haemodialysis.