RESUMO
The major source of vitamin D is endogenous synthesis under sunlight exposure, thus, vitamin D deficiency is uncommon in healthy people living in a tropical area where sunshine is plentiful. However, long-stay hospitalized patients who do not get direct sunlight may become vitamin D deficient. The authors studied the prevalence of vitamin D deficiency in patients without other risk factors for vitamin D deficiency who had been admitted to Songklanagarind Hospital for longer than 27 days. The second objective was to identify predictive factors for vitamin D deficiency. Considered variables were clinical character, basic laboratory results, and intact parathyroid hormone level (iPTH). Among 60 patients studied, there were 12 patients who were vitamin D deficient and only one had a level lower than 8 ng/ml. Despite vitamin D deficiency, average serum calcium was normal. Patients in the vitamin D deficient group had lower serum corrected calcium and higher iPTH level than patients in the vitamin D sufficient group. No other clinical or laboratory data could predict a vitamin D deficiency state. In summary, the present tropical area study showed that 20 per cent of long-stay hospitalized patients who had a mild degree of vitamin D deficiency and 1.7 per cent had severe vitamin D deficit. Vitamin D supplementation is unnecessary in this group of patients.