Vitamin D deficiency contributes directly to the acute respiratory distress syndrome (ARDS)

Rationale

Vitamin D deficiency has been implicated as a pathogenic factor in sepsis and intensive therapy unit mortality but has not been assessed as a risk factor for acute respiratory distress syndrome (ARDS). Causality of these associations has never been demonstrated.

Objectives

To determine if ARDS is associated with vitamin D deficiency in a clinical setting and to determine if vitamin D deficiency in experimental models of ARDS influences its severity.

Methods

Human, murine and in vitro primary alveolar epithelial cell work were included in this study.

Findings

Vitamin D deficiency (plasma 25(OH)D levels <50 nmol/L) was ubiquitous in patients with ARDS and present in the vast majority of patients at risk of developing ARDS following oesophagectomy. In a murine model of intratracheal lipopolysaccharide challenge, dietary-induced vitamin D deficiency resulted in exaggerated alveolar inflammation, epithelial damage and hypoxia. In vitro, vitamin D has trophic effects on primary human alveolar epithelial cells affecting >600 genes. In a clinical setting, pharmacological repletion of vitamin D prior to oesophagectomy reduced the observed changes of in vivo measurements of alveolar capillary damage seen in deficient patients.

Conclusions

Vitamin D deficiency is common in people who develop ARDS. This deficiency of vitamin D appears to contribute to the development of the condition, and approaches to correct vitamin D deficiency in patients at risk of ARDS should be developed.

Trial registration

UKCRN ID 11994.

Unusual presentation of calcaneal osteomyelitis. Twenty-five years after inoculation

An unusual presentation of calcaneal osteomyelitis is described, where-by the infection remained undiagnosed for 25 years. The 36-year-old patient recently sought medical treatment for a reported ankle sprain, but the pain was recalcitrant to conservative care. Further investigation yielded a history significant for stepping on a chicken bone as a child, which entered the inferior lateral heel. Magnetic resonance imaging revealed what plain radiographs did not: a well demarcated lytic lesion in the body of the calcaneus. Intraoperative findings were consistent with an abscess of chronic osteomyelitis. The treatment included incision and drainage, antibiotic beads, and a tricortical bone graft.