Raised serum calcium in tuberculosis patients in Africa.

Reports of raised serum calcium in the presence of tuberculosis have tended to be from centres where sunlight is plentiful. U.K.-based data have suggested that normocalcaemia prevails. In a prospective study of 15 African patients with pulmonary tuberculosis, resident in East Africa, corrected serum calcium was significantly lower in a control healthy group (2.59 mmol/l +/- 0.08 and 2.49 +/- 0.06 mmol/l respectively: P less than 0.001). Serum 25-hydroxy vitamin D was significantly lower in the patient group (median, 15.9 ng/ml, range 6.7-35.7) compared with the control group (median 26.2 ng/ml, range 10.5-45.9, P less than 0.05). No significant difference was found between patients and controls for 1,25-dihydroxy vitamin D or parathyroid hormone. No correlation was found between serum calcium and 1,25 (OH)2 D3. Serum albumin showed a negative correlation with radiographic extent of disease and with extent of cavitation. Where sunlight is plentiful, relatively high serum 25-hydroxy Vitamin D may give rise to raised serum calcium in the presence of tuberculosis.