Tuberculosis:
The first treatment of skin tuberculosis was discovered by lamp arc
radiation and the inventor Neils Rayberg Finsen (1890-1904) was awarded
by Noble prize for this discovery (94). It is suggested that UV
radiation from lamp arc produces vitamin D in the body and facilitates
the production of anti-microbial peptides such as cathelicidin to fight
against infectious diseases including tuberculosis (95, 96, 97). Many
observational studies showed strong association of vitamin D deficiency
with tuberculosis in different populations including Pakistani
population (98, 99, 100).
Some of the case control studies found severe vitamin D deficiency in
patients with pulmonary and extra pulmonary tuberculosis (98, 101, 102,
103, 104, 105, 106, 107). A case control study designed to evaluate the
amount of vitamin D, anti-microbial peptide cathelicidin, chemerin and
inflammatory marker TNF α in pulmonary tuberculosis and healthy subjects
found significant association was present between vitamin D,
cathelicidin, chemerin and TNF α. (108).
An interventional trial named as SUCCINIT study (Supplementary
cholecalciferol in recovery from tuberculosis) was conducted in patients
with pulmonary tuberculosis to evaluate the effects of vitamin D
supplementation (109). A total of 259 patients with newly diagnosed TB
were randomly divided into two groups (Vitamin D group n=132 and placebo
group n=129). The vitamin D group was administered by 600000 IU of
vitamin D on weekly basis for two weeks along with standard medications
while, placebo group was administered by normal saline along with
standard medications. The results of this study showed improvement in
clinical, radiological and host defense outcomes in the patients of
vitamin D group.
Another interventional trial was conducted to evaluate adjuvant effects
of vitamin D with anti-tuberculosis therapy (ATT) as compared with ATT
alone for 77 days (110). The results showed improvement in some
parameters such as increase in serum vitamin D, calcium, BMI and
hemoglobin and decrease in erythrocytes sedimentation rate (ESR),
C-reactive proteins (CRP), total white blood count and a 12 days earlier
sputum conversion as compared with placebo group.
A similar study also showed early sputum conversion in smear positive
pulmonary tuberculosis by the administration of vitamin D (100000 IU) on
every fourteenth day for three months (111). The results showed
improvement in the vitamin D levels and rate of sputum smear conversion
in patients with pulmonary tuberculosis.
CXCL10 is a chemo-attractant factor that is found to be elevated in TB
patients (112). Vitamin D levels were found negatively associated with
the CXCL10 levels in 119 TB patients in Karachi (113).