Testing for Vitamin D in High-Risk COPD in Outpatient Clinics in Spain: A Cross-Sectional Analysis of the VITADEPOC Study

Vitamin D deficiency in chronic obstructive pulmonary disease

PURPOSE OF REVIEW

There is biological and epidemiological evidence supporting a role for vitamin D in the respiratory system, and vitamin D deficiency (VDD) may be associated with poor health outcomes in people with chronic obstructive pulmonary disease (COPD). This review summarizes recent findings relevant to the role of vitamin D in COPD.

RECENT FINDINGS

The prevalence of VDD in people with COPD may be underestimated. Treatment of severe VDD [serum 25(OH)D3 < 10 ng/ml] may reduce the risk of COPD exacerbations. Vitamin D supplementation may also improve functional capacity and quality of life in people with COPD. However, there is no strong evidence that vitamin D supplementation slows the decline in lung function.

SUMMARY

Although there are many known associations between vitamin D and COPD outcomes, the causal nature of these associations and the precise benefits of vitamin D supplementation remain unclear. High-quality randomized controlled trials are necessary.

Osteoporosis in Patients With Respiratory Diseases

Climate change, environmental pollution, and virus epidemics have sharply increased the number of patients suffering from respiratory diseases in recent years. Prolonged periods of illness and drug use increase the occurrence of complications in these patients. Osteoporosis is the common bone metabolism disease with respiratory disturbance, which affects prognosis and increases mortality of patients. The problem of osteoporosis in patients with respiratory diseases needs more attention. In this review, we concluded the characteristics of osteoporosis in some respiratory diseases including COPD, asthma, COVID-19, tuberculosis, and lung cancer. We revealed that hypoxia was the common pathogenesis of osteoporosis secondary to respiratory diseases, with malnutrition and corticosteroid abuse driving the progression of osteoporosis. Hypoxia-induced ROS accumulation and activated HIF-1α lead to attenuated osteogenesis and enhanced osteoclastogenesis in patients with respiratory diseases. Tuberculosis and cancer also invaded bone tissue and reduced bone strength by direct infiltration. For the treatment of osteoporosis in respiratory patients, oral-optimized bisphosphonates were the best treatment modality. Vitamin D was a necessary supplement, both for calcium absorption in osteogenesis and for improvement of respiratory lesions. Reasonable adjustment of the dose and course of corticosteroids according to the etiology and condition of patients is beneficial to prevent the occurrence and development of osteoporosis. Additionally, HIF-1α was a potential target for the treatment of osteoporosis in respiratory patients, which could be activated under hypoxia condition and involved in the process of bone remodeling.