Obesity attenuates serum 25-hydroxyvitamin D response to cholecalciferol therapy in critically ill patients

Obesity and critical care nutrition: current practice gaps and directions for future research

Background

This review has been developed following a panel discussion with an international group of experts in the care of patients with obesity in the critical care setting and focuses on current best practices in malnutrition screening and assessment, estimation of energy needs for patients with obesity, the risks and management of sarcopenic obesity, the value of tailored nutrition recommendations, and the emerging role of immunonutrition. Patients admitted to the intensive care unit (ICU) increasingly present with overweight and obesity that require individualized nutrition considerations due to underlying comorbidities, immunological factors such as inflammation, and changes in energy expenditure and other aspects of metabolism. While research continues to accumulate, important knowledge gaps persist in recognizing and managing the complex nutritional needs in ICU patients with obesity. Available malnutrition screening and assessment tools are limited in patients with obesity due to a lack of validation and heterogeneous factors impacting nutrition status in this population. Estimations of energy and protein demands are also complex in patients with obesity and may include estimations based upon ideal, actual, or adjusted body weight. Evidence is still sparse on the role of immunonutrition in patients with obesity, but the presence of inflammation that impacts immune function may suggest a role for these nutrients in hemodynamically stable ICU patients. Educational efforts are needed for all clinicians who care for complex cases of critically ill patients with obesity, with a focus on strategies for optimal nutrition and the consideration of issues such as weight stigma and bias impacting the delivery of care.

Conclusions

Current nutritional strategies for these patients should be undertaken with a focus on individualized care that considers the whole person, including the possibility of preexisting comorbidities, altered metabolism, and chronic stigma, which may impact the provision of nutritional care. Additional research should focus on the applicability of current guidelines and evidence for nutrition therapy in populations with obesity, especially in the setting of critical illness.

Reduction in Hypercalcemia Following Readjustment of Target Serum 25-Hydroxy Vitamin D Concentration during Cholecalciferol Therapy in Vitamin D-Deficient Critically Ill Patients

The intent of this study was an evaluation of our effort to reduce the incidence of hypercalcemia in critically ill vitamin D-deficient patients with multiple traumatic injuries given cholecalciferol. Vitamin D deficiency was defined as a serum 25-hydroxy vitamin D concentration (25-OH vit D) of <20 ng/mL. Adult patients (>17 years of age) were given 10,000 IU of cholecalciferol daily with an intended target 25-OH vit D of >19.9 ng/mL. These patients were compared to a historical control group that underwent therapy with a higher target of >29.9 ng/mL. Patients received cholecalciferol via the feeding tube along with enteral nutrition (EN) until the target 25-OH vit D was achieved, EN discontinued, the nutrition support service signed off the patient, or the patient was discharged from the TICU. Patients were included if two consecutive weekly 25-OH vit D were measured. One hundred and three critically ill trauma patients were retrospectively studied. Fifty were given cholecalciferol therapy with the new lower target 25-OH vit D, and 53 were from a historical cohort aiming for the higher target. Hypercalcemia (serum ionized calcium concentration > 1.32 mmol/L) was reduced from 40% (21 out of 53 patients) to 4% (2 out of 50 patients; p < 0.001). None of the hypercalcemic patients were symptomatic. Readjustment of target 25-OH vit D concentration resulted in a ten-fold decrease in the rate of hypercalcemia and improved the safety of cholecalciferol therapy for critically ill patients with traumatic injuries.

Ultra-processed diet, systemic oxidative stress, and breach of immunologic tolerance

In recent years, consumption of ultra-processed food around the world has been increasing. The nutritional profile of an ultra-processed diet is associated with the development of cellular alterations that lead to oxidative stress. The chronic prooxidative state leads to an environment that influences the proliferation, apoptosis, and signaling pathways of immune cells. Likewise, the decrease in the transcription factor NRF2, owing to exacerbated production of reactive oxygen species, leads to changes in immune function and response to infections. This review aims to analyze the connection between an ultra-processed diet, systemic oxidative stress, and immune tolerance, as a contribution to the scientific evidence on the impact of oxidative stress on health and the possible risk of infections-an important consideration in the association of eating pattern and the immune response.

Hypercalcemia Without Hypervitaminosis D During Cholecalciferol Supplementation in Critically Ill Patients

BACKGROUND

Vitamin D deficiency during critical illness has been associated with worsened outcomes. Because most critically ill patients with severe traumatic injuries are vitamin D deficient, we investigated the efficacy and safety of cholecalciferol therapy for these patients.

METHODS

Fifty-three patients (>17 years of age) admitted to the trauma intensive care unit who had a serum 25-hydroxy vitamin D (25-OH vit D) concentration <20 ng/mL were given 10,000 IU of cholecalciferol daily. Efficacy was defined as achievement of a 25-OH vit D of 30-79.9 ng/mL. Safety was evaluated by the presence of hypercalcemia (serum ionized calcium [iCa] >1.32 mmol/L) or hypervitaminosis D (25-OH vit D >79.9 nmol/L). Patients were monitored for 2 weeks during cholecalciferol therapy.

RESULTS

Twenty-four patients (45%) achieved target 25-OH vit D. No patients experienced hypervitaminosis D. Hypercalcemia occurred in 40% (n = 21) of patients; 2 patients experienced an iCa >1.49 nmol/L. 25-OH vit D was significantly greater for those who developed hypercalcemia (37.2 + 11.2 vs 28.4 + 5.6 ng/mL, respectively, P < 0.001) by the second week of cholecalciferol. Of 24 patients who achieved target 25-OH vit D, 14 (58%) experienced hypercalcemia in contrast to 24% of patients (7 out of 29) who did not achieve target 25-OH vit D (P = 0.024).

CONCLUSIONS

Cholecalciferol normalized serum 25-OH vit D concentrations in less than half of patients yet was associated with a substantial proportion of patients with hypercalcemia without hypervitaminosis D.