The relationship between vitamin C or thiamine levels and outcomes for severe sepsis patients admitted to the ICU

Prevalence, risk factors, and clinical outcomes of vitamin C deficiency in adult hospitalized patients in high-income countries: a scoping review

BACKGROUND

Assessment for vitamin C deficiency (VCD) is rarely undertaken in an acute hospital setting in high-income countries. However, with growing interest in VCD in community settings, there is emerging evidence investigating the prevalence and impact of VCD during hospitalization.

OBJECTIVES

In this scoping review, the prevalence of VCD in adult hospitalized patients is explored, patient characteristics are described, and risk factors and clinical outcomes associated with VCD are identified.

METHODS

A systematic scoping review was conducted in accordance with the PRISMA-ScR framework. The Ovid MEDLINE, Ovid Embase, Scopus, CINAHL Plus, Allied and Complementary Medicine Database, and the Cochrane Library databases were searched for interventional, comparative, and case-series studies that met eligibility criteria, including adult hospital inpatients in high-income countries, as defined by the Organization for Economic Co-operation and Development, that reported VCD prevalence using World Health Organization reference standards. These standards define VCD deficiency as plasma or serum vitamin C level <11.4 µmol/L, wholeblood level <17 µmol/L, or leukocytes <57 nmol/108 cells.

RESULTS

Twenty-three articles were included, representing 22 studies. The cumulative prevalence of VCD was 27.7% (n = 2494; 95% confidence interval [CI], 21.3-34.0). High prevalence of VCD was observed in patients with severe acute illness and poor nutritional status. Scurvy was present in 48% to 62% of patients with VCD assessed in 2 studies (n = 71). Being retired (P = 0.015) and using excessive amounts of alcohol and tobacco (P = 0.0003) were independent risk factors for VCD (n = 184). Age was not conclusively associated with VCD (n = 631). Two studies examined nutrition associations (n = 309); results were inconsistent. Clinical outcomes for VCD included increased risk of frailty (adjusted odds ratio, 4.3; 95%CI, 1.33-13.86; P = 0.015) and cognitive impairment (adjusted odds ratio, 2.93; 95%CI, 1.05-8.19, P = 0.031) (n = 160).

CONCLUSIONS

VCD is a nutritional challenge facing the healthcare systems of high-income countries. Research focused on early identification and treatment of patients with VCD is warranted.

SYSTEMATIC REVIEW REGISTRATION

Open Science Framework ( https://doi.org/10.17605/OSF.IO/AJGHX ).

Association between Vitamin C Deficiency and Mortality in Patients with Septic Shock

The prognostic value of low vitamin C levels has not been well investigated in patients with septic shock. We aimed to evaluate the association of vitamin C deficiency with mortality in patients with septic shock. We conducted a retrospective analysis of 165 patients with septic shock from a prospective multicenter trial and institutional sepsis registry between April 2018 and January 2020. The primary outcome was 28-day mortality. The patients were categorized into vitamin C deficiency and normal groups based on a vitamin C cutoff level of 11.4 mmol/L. Multivariable Cox regression analysis was performed to examine the association between vitamin C levels and 28-day mortality. A total of 165 patients was included for analysis and 77 (46.7%) had vitamin C deficiency. There was no significant difference in the 28-day mortality rate between the vitamin C deficiency group and the normal group (23.4% (n = 18/77) vs. 13.6% (n = 12/88), p = 0.083). Multivariable Cox proportional hazard analysis showed vitamin C deficiency to be associated with increased risk of 28-day mortality (adjusted hazard ratio, 2.65, 95% confidence interval (CI), 1.08–6.45; p = 0.032). Initial vitamin C deficiency was associated with a higher risk of 28-day mortality in patients with septic shock after adjusting for intravenous administration of vitamin C and thiamine, baseline characteristics, laboratory findings, and severity of illness.