Scientists have discovered that adding high doses of vitamin D
to standard antibiotic treatment can help people with tuberculosis
(TB) recover more quickly and reduce lung damage.
For many years vitamin D was only thought to be important for
bone health. More recently, researchers have found that it might
have a range of other functions in our bodies, including a possible
role in preventing cancer, type 2 diabetes and autoimmune diseases
- conditions like multiple sclerosis where a person's immune system
mistakenly attacks healthy cells.
There is also growing speculation about the benefits of vitamin
D in preventing and treating lung infections including TB, and
there is some evidence from laboratory studies that the vitamin may
help TB recovery. In fact, in the days before antibiotics, vitamin
D from sunlight was a recommended treatment for TB patients in
sanatoria.
This is the first study to assess the effect of the vitamin on
immune responses in patients being treated for the often fatal lung
disease, which was responsible for 1.4 million deaths in 2010.
The researchers, led by Dr Adrian Martineau of Queen Mary
University of London and the MRC's National Institute for Medical
Research (NIMR; now part of the Francis Crick
Institute) randomly allocated 95 TB patients at clinics
across London to receive either high doses of vitamin D or a
placebo in addition to the standard antibiotics for the first eight
weeks of their treatment. Dr Anna Coussens of NIMR's Division
of Mycobacterial Research measured levels of various immune
molecules and markers of inflammation in the patients' blood every
two weeks during treatment.
"A large number of these inflammatory markers fell further and
faster in patients receiving vitamin D than those given the
placebo," explained Dr Martineau.
He added: "Our findings indicate that vitamin D may have a role
in accelerating resolution of inflammatory responses. This is
important, because sometimes these inflammatory responses can cause
tissue damage, leading to the development of cavities in the lung.
If we can help these cavities to heal more quickly, then patients
should be infectious for a shorter period of time, and may also
suffer less lung damage."
The scientists suggest that vitamin D might also be useful as an
addition to treatment for other lung infections, including
pneumonia, where inflammatory responses have been shown to be
damaging.
The researchers worked with colleagues from Guy's and St Thomas'
NHS Foundation Trust, Newham Chest Clinic, Homerton University NHS
Foundation Trust, Whipps Cross University Hospital, Northwick Park
Hospital, Lewisham Hospital and King's College Hospital. The work
was jointly funded by the MRC and the British Lung Foundation.
The paper, 'Vitamin D accelerates resolution of
inflammatory responses during tuberculosis treatment,'
is published in the Proceedings of the National Academy of
Sciences.