Vitamin D Supplementation Linked to Reduced In-Hospital, ICU Mortality in Patients With COPD

Vitamin D supplementation may reduce in-hospital and intensive care unit (ICU) mortality in patients with chronic obstructive pulmonary disease (COPD), according to a study published in Frontiers in Medicine.¹

The researchers explained that patients with severe COPD often require ICU admission because of acute exacerbations or respiratory failure. Despite recent advancements, they noted that the mortality rate of ICU-admitted patients with COPD remains high. Therefore, the researchers emphasized the need to identify modifiable factors that influence patient outcomes to improve their prognosis.

They noted that emerging evidence suggests that vitamin D, which is well known for its roles in bone health, immune function, and calcium metabolism, may play an essential role in respiratory health and disease outcomes in patients with COPD. For example, a past study found that vitamin D regulates immune responses, enhances antimicrobial defenses, and modulates inflammation, which may help reduce the risk of respiratory infections and subsequent mortality.² Similarly, another study explained that vitamin D directly affects respiratory muscle function and lung tissue, meaning it may also influence disease progression and outcomes in patients with COPD.³

However, one study found that vitamin D deficiency is highly prevalent among patients with COPD due to limited sun exposure, altered metabolism, and impaired synthesis; patients who are vitamin D deficient do not receive the benefits previously listed.⁴ Also, despite its potential, the researchers noted that it remains unclear how vitamin D supplementation impacts the mortality rates of ICU-admitted patients with COPD.¹ Because of this, they conducted a study to better understand the relationship between vitamin D supplementation and mortality outcomes in ICU-admitted patients with COPD.

Vitamin D | Image Credit: MP Studio - stock.adobe.com

To do so, they used data from the Medical Information Marketplace in Intensive Care IV (MIMIC-IV), which contains comprehensive data on 315,460 patients admitted to the ICU at Beth Israel Deaconess Medical Center (BIDMC) between 2008 to 2019, focusing on those diagnosed with COPD upon admission. However, the researchers excluded those younger than 18 years old, those who had repeated hospital or ICU admissions, or those who had a hospital or ICU stay of less than 24 hours.

The study population consisted of 3203 patients with COPD. The researchers divided them into 2 groups based on their vitamin D use; they placed 587 patients in the vitamin D group and 2616 patients in the non-vitamin D group.

Patients in the vitamin D group had notably higher in-hospital survival rates (P < .001). More specifically, in the unadjusted model, in-hospital (HR, 1.9; 95% CI, 1.4-2.4; P < .001) and ICU mortality (HR, 1.9; 95% CI, 1.3-2.6; P = .001) rates were significantly higher in the non-vitamin D group. After adjusting for confounding variables, the non-vitamin D group remained at an elevated risk of in-hospital (HR, 1.7; 95% CI, 1.3-2.3; P < .001) and ICU mortality (HR, 1.8; 95% CI, 1.6-2.6; P = .003) when compared with the vitamin D group.

Additionally, the researchers performed subgroup analyses of in-hospital and ICU mortality outcomes based on clinically meaningful scores and several comorbidities. In particular, they observed a significant interaction between gender and in-hospital mortality, as female patients with COPD who received vitamin D supplementation showed a reduced risk of in-hospital mortality.

The researchers acknowledged several study limitations, one being that they could not obtain either the vitamin D levels in administration or the after-treatment trends since it was a retrospective cohort study. Also, the study only focused on whether patients with COPD were supplemented with vitamin D, not their specific dosage. Based on their study's findings and limitations, the researchers suggested areas for further research. 

“Vitamin D is an inexpensive and safe drug, and so further clinical trials should be conducted to provide more-solid evidence on whether it improves the prognosis of ICU hospitalized COPD patients,” the authors concluded.

References

1. He Q, Hu S, Xie J, Ge Y, Li C. Vitamin D supplementation may be beneficial in improving the prognosis of patients with chronic obstructive pulmonary disease in the intensive care unit: a retrospective study. Front Med (Lausanne). 2024;11:1334524. doi:10.3389/fmed.2024.1334524

2. Huang W, Xie R, Hong Y, Chen Q. Association between comorbid chronic obstructive pulmonary disease and prognosis of patients admitted to the intensive care unit for non-COPD reasons: a retrospective cohort study. Int J Chron Obstruct Pulmon Dis. (2020) 15:279–87. doi:10.2147/COPD.S244020

3. Gawron G, Trzaska-Sobczak M, Sozańska E, Śnieżek P, Barczyk A. Vitamin D status of severe COPD patients with chronic respiratory failure. Adv Respir Med. (2018)86:78–85. doi:10.5603/ARM.2018.0010

4. Afzal M, Kazmi I, Al-Abbasi FA, Alshehri S, Ghoneim MM, Imam SS, et al. Current overview on therapeutic potential of vitamin D in inflammatory lung diseases. Biomedicines.(2021)9:21843. doi:10.3390/biomedicines9121843