Everyone seems convinced that vitamin C has wonderful preventative and curative powers for viral illnesses like colds and 'flu despite the fact that there is very little evidence to support the belief. Evidence is starting to build though, that vitamin D might be much more significant in the maintenance of health.
There are two main ways to top up your vitamin D supplies. One is to expose you skin to sunlight and the other is to eat animal fats - in particular oily fish.
It has been long been recognised as the substance that prevents rickets - a deficiency disease in babies and young children in which bones are inadequately calcified. The leg bones bend under the child's weight, the skull can be as thin as a ping-pong ball and the whole skeleton is deformed.
We now know that there are receptors for vitamin D on the surface of cells all over the body, including immune cells and not just in bone cells. Receptors are like mail boxes - you don't have them, unless you are expecting some mail. There is particular research interest in the way this vitamin interacts with tuberculosis (TB).
TB is a bacterial disease that has evolved a unique relationship the immune system. Many people infected with the TB bacterium remain healthy. The immune system often manages to contain pockets of infection as harmless nodules so that the disease is “latent”. As long as the immune system can successfully maintain this state of siege the TB cannot spread and inflict further damage. It is well know that those with an HIV-damaged immune system are susceptible.
Before the advent of antibiotics, TB was very difficult to treat but sunshine therapy was one of the methods that seemed to be helpful in pushing the disease back into latency. There is a complex interplay between immune cells and TB bacteria and there is a strong suspicion that one of the things that helps the immune system to maintain its ability to contain the disease is to have an adequate supply of vitamin D in the body. Research recently published seems to show that giving patients supplements of vitamin D (alongside their antibiotics) significantly speeds recovery.
There are other clinical trials taking place into the links between vitamin D and a range of diseases. This is one of the most interesting lines of current research, in terms of things individuals might be able to do to support the function of their own immune systems.
A variety of TB that is resistant to all available drug treatments is no longer a spectre but a reality. Several cases have been identified in India. Once this starts spreading across the globe, and spread it inevitably will, TB will become an incurable killer as it was in the 19th and early 20th centuries. Anything we can discover that will help people resist this disease will be important to individual and public health.
Queen Mary, University of London. "High doses of vitamin D help tuberculosis patients recover more quickly." ScienceDaily, 3 Sep. 2012. Web. 24 Sep. 2012. http://www.sciencedaily.com/releases/2012/09/120903154008.htm