Vitamin D and Immunity

The Sunshine Vitamin

Did you know that vitamin D is nick-named the sunshine vitamin because we produce it through a chemical reaction that takes place in our skin in the presence of sunlight? In Canada and other northern countries this can create a problem during the winter months. Speculation, controversy and finally good research is pointing to some potentially very important health concerns revolving around vitamin D. People that live in northern climate countries like Canada should take particular note and take steps to ensure that they are getting enough vitamin D.

Traditionally, the importance of vitamin D had been linked to bone and skeletal health. It is widely known and accepted at this point that adequate vitamin D levels are vital to maintain proper bone health. Inadequate amounts of vitamin in children can also lead to a bone softening disease known as rickets. It is now known that vitamin D actually plays a vital role in a number of other biochemical processes in the body. One of the more relevant recent discoveries is the vital role that vitamin D plays in immune system function.

Like many great discoveries, the early effects of vitamin D on immunity were discovered by mistake and almost unknowingly. Before the advent of antibiotics, the treatment for tuberculosis often involved isolating the unfortunate infected people in sanitoriums and prescribing direct sunlight as this was thought to kill the tuberculosis directly. Cod liver oil was also prescribed because in those days, it was thought to be good for what ails you. Of course, the exposure to sunlight increased vitamin D production and cod liver oil is also a good source of vitamin D. These treatments did result in positive outcomes, although the actual mechanism for the success was not correctly understood.

There have been multiple studies that have shown a clear correlation between decreased serum vitamin D levels and increased susceptibility to infection. One interesting study involving 800 military personnel in Finland found that those with decreased levels of vitamin D lost significantly more days of active duty due to respiratory tract infections than did their counterparts with higher serum levels of vitamin D. It is also theorized that part of the seasonal nature of colds and the flu may be partly attributed to declining vitamin D levels during the winter months.

Decreased levels of vitamin D have also been associated with a greater incidence of autoimmune diseases such as multiple sclerosis, rheumatoid arthritis and lupus. One stark example of this is that there is a marked increase in the incidence of multiple sclerosis in northern climate countries like Canada, while it is almost unheard of in countries closer to the equator. This has led to speculation that decreased vitamin D levels could be playing a role in the development of the disease. A more recent discovery found that lower maternal levels of vitamin D during pregnancy may be linked to an increase in diabetes mellitus in children. This information all points toward the vital role that vitamin D may play in immune system function.

Canadians generally do have lower levels of serum vitamin D in our systems. Much of this might be attributed to our winter climate and the lack of sun exposure during this time. As a result, many of us might be more susceptible to infection as well as the development of other conditions and diseases. During the current pandemic we are focused on anything that can help boost our immunity. Health Canada does have recommendations regarding vitamin D supplementation. I would suggest looking up the guidelines and consider possible supplementation if you think that it might be appropriate. As always, it is advisable to check with your healthcare provider, MD or pharmacist to avoid any conflicts with medication or medical conditions.