In reply: We thank Grant for his interest in our study on pneumonia severity assessment in tropical Australia. Our revised scoring system included increased weighting for hypoalbuminaemia, as well as adding a point for Indigenous status, because these two factors had the strongest association with the need for intensive respiratory or vasopressor support on univariate analysis.1 Unlike vitamin D status, these and the other factors included in the scoring system are readily available measures that can be used in the clinical setting to rapidly predict the need for intensive support. The scoring system was not intended to identify underlying aetiology or risk factors for severe pneumonia. For example, Indigenous status is likely to be a surrogate measure for undiagnosed comorbidities, lack of access to health care, and socioeconomic disadvantage.
We agree that vitamin D is important in immune function and that the levels of insufficiency that result in impaired resistance to infection are not well defined.2 Most data on vitamin D deficiency in dark-skinned populations in Australia come from temperate areas,3,4 and the reference offered by Grant to support the concern about vitamin D deficiency does not cite any data from Australian populations north of southern Queensland.5 Further studies are needed on the prevalence of vitamin D deficiency in Indigenous Australians in tropical areas, and the additional contribution of vitamin D deficiency independent of known risk factors of severity and outcome.
- 1. Davis JS, Cross GB, Charles PGP, et al. Pneumonia risk stratification in tropical Australia: does the SMART-COP score apply? Med J Aust 2010; 192: 133-136. <MJA full text>
- 2. Ralph AP, Kelly PM, Anstey NM. L-arginine and vitamin D: novel adjunctive immunotherapies in tuberculosis. Trends Microbiol 2008; 16: 336-344.
- 3. Erbas B, Ebeling PR, Couch D, Wark JD. Suburban clustering of vitamin D deficiency in Melbourne, Australia. Asia Pac J Clin Nutr 2008; 17: 63-67.
- 4. Benson J, Wilson A, Stocks N, Moulding N. Muscle pain as an indicator of vitamin D deficiency in an urban Australian Aboriginal population. Med J Aust 2006; 185: 76-77. <MJA full text>
- 5. Nowson CA, Margerison C. Vitamin D intake and vitamin D status of Australians. Med J Aust 2002; 177: 149-152. <MJA full text>
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