The Medical Journal of Basrah University

Background
Low vitamin D levels had been reported to be associated with a wide range of health problems, one of them is tuberculosis. the aim is to estimate vitamin D serum concentration among patients with tuberculosis at baseline, 2 and 5 months after starting anti-tuberculosis treatment.
Methods
The study was carried out at the TB Center and College of Medicine in Basrah (Iraq), during the period from September 2018 to June 2019. Participants were newly diagnosed tuberculosis patients, and their matched apparently healthy controls. Total 25-hydroxy vitamin D in serum was estimated using chemiluminescent microparticle immunoassay. Calcium, phosphorus, alkaline phosphatase, parathyroid hormone, and others, were also measured.
Results
There were no statistically significant difference in the mean levels of vitamin D between tuberculosis patients at baseline (n=56) and control subjects (n=57). The prevalence of vitamin D deficiency was high in patients and their controls at baseline where more than 80% of them had a vitamin D level below 20 ng/ml.
When patients were followed two months after starting anti-tuberculosis treatment, the mean serum vitamin D level was significantly lower than that at baseline. Despite the wide spread vitamin D deficiency among TB patients, all smear-positive pulmonary TB patients, except 3, had sputum conversion after 2 months of treatment.
Conclusions
The prevalence of vitamin D deficiency is high with no significant difference between tuberculosis patients at baseline and their matched normal controls. Vitamin D deficiency did not seem to affect the response of patients to anti-TB treatment.

Background: Low vitamin D levels had been reported to be common in normal subjects worldwide. Studies in the Middle East had reported extremely low levels of serum vitamin D, despite high exposure to sunlight. Aim: To estimate vitamin D serum concentration in a sample of apparently healthy subjects from Basrah, by 2 methods (chemiluminescent and fluorescent assays). Methods: The study was carried out on apparently healthy subjects during the period from September 2018 to February 2019. Quantitative determination of the total 25-hydroxy vitamin D in serum was made using chemiluminescent microparticle immunoassay and enzyme-linked fluorescent assay. Other parameters (calcium, phosphorus, alkaline phosphatase, parathyroid hormone, hemoglobin, and erythrocyte sedimentation rate and body mass index) were also measured. Results: The mean level of vitamin D measured by the two methods, was 11.57±6.63 ng/ml and 13.31±6.52 ng/ml by chemiluminescent and fluorescent assays respectively. The prevalence of vitamin D deficiency was high, where more than 80% of the 57 subjects had vitamin D level below 20 ng/ml. If the cut-off point of vitamin D deficiency was taken as 10 ng/ml, around 46% of the subjects were found deficient in both methods. Although the two methods of vitamin D assay were well correlated with each other, fluorescent assay gave, on average, a significantly higher levels compared with the chemiluminescent method. Serum parathyroid hormone, showed a negative correlation with vitamin D serum levels. After excluding children and females, no significant difference was found between adult smokers and non-smokers when vitamin D was measured by both methods.Conclusion: Vitamin D deficiency is common (> 80%) among normal subjects. The enzyme-linked fluorescent assay resulted in higher mean level than chemiluminescent assay. The use of a deficiency cut-off point of 10 ng/ml may be more appropriate.