Tuberculosis is an infectious disease that continues to claim significant numbers of lives around the World. Before the advent of antibiotics, many tuberculosis sufferers were shipped off to ‘sanitoriums’: often rurally-located facilities where individuals would typically spend a year or more to rest, eat well, and hopefully overcome their illness.
While rest and a healthy diet were thought to be the cornerstones of treatment, some have suggested that another maybe beneficial element of sanitorium life was its potential to allow exposure to sunlight. Vitamin D, produced in response to sunlight, is known to have immune-enhancing effects. In one study, for instance, a single dose of vitamin D (2.5 mg/100,000 IU) led to improved immune function against the tuberculosis organism [1].
It is now known that vitamin D (produced in response to sunlight) stimulates the secretion of natural antibiotics known as ‘anti-microbial peptides’. This gives vitamin D the potential to combat a range of infections.
Recently, the role of vitamin D as an anti-infective agent was assessed in the form of a review [2]. 13 studies were reviewed, of which 9 were ‘double-blind and placebo-controlled’ ” generally regarded as the best study design to discern whether a treatment has a real benefit or not. Some of these studies assessed the role of vitamin D in the treatment of tuberculosis.
Overall, the results showed that vitamin D therapy shows considerable potential in the treatment of tuberculosis. The results also showed vitamin D can be effective for the treatment of other infections, including flu and viral upper respiratory tract illnesses (e.g. cold). In addition, adverse events due to vitamin D supplementation were rare.
This review suggests that ensuring optimal vitamin D levels (through appropriate sunlight exposure, diet and, if necessary, supplementation) is likely to help ensure optimal protection from infectious diseases. This has particular relevance in the winter, then vitamin D levels tend bottom out. In fact, lower levels of vitamin D may well be a factor in why it is that infection diseases (such as cold, flu and pneumonia) tend to be more common in the winter. Awhile back I wrote about a study which found lower levels of vitamin D to be associated with a greater need to take sick days due to upper respiratory tract infections (e.g. cold and sore throat). For more about this, see here.
References:
1. Martineau AR, et al. A Single Dose of Vitamin D Enhances Immunity to Mycobacteria American Journal of Respiratory and Critical Care Medicine. 2007;176:208-213
2. Yamshchikov AV, et al. Vitamin D for Treatment and Prevention of Infectious Diseases: A Systematic Review of Randomized Controlled Trials Endocr Pract. 2nd June 2009 [Epub ahead of print].
