Vitamin D Protects Against Colds, Flu and Viral Infections

Vitamin D is an essential cofactor in the prevention of a host of conditions ranging from cancer to diabetes, dementia and cardiovascular disease. The sunshine vitamin is a critical part of our evolution as it has been circulating in our ancestral blood for countless generations due to plentiful sun exposure. It has only been the past half-century that we have lathered ourselves with sunscreen and hidden in buildings away from the vitamin D producing effects of the sun, following the sage advice of doctors and other misinformed medical professionals.

Vitamin D Levels Diminish with Age, Increasing Risk for Colds and Influenza

Vitamin D is rapidly emerging as one of the most researched natural compounds demonstrated to promote human health. More evidence in support of the prohormone is provided by researchers in Spain publishing the result of their work in the Journal of Leukocyte Biology. Scientists have found that insufficient levels of vitamin D are related to a deficiency in our innate immune defenses that protect us from infections, neoplasias or autoimmune diseases, and can effectively shield us from the common cold and influenza during winter months.

To perform the analysis and gather data for this study, researchers compared the changes in the blood levels of vitamin D among three groups of healthy subjects: youth (aged 20 to 30), middle-aged (aged 31 to 59), and elderly (aged 60 to 86). The scientists found decreased levels of vitamin D with aging, likely due to decreased exposure to the sun and a decline in the native ability of skin receptors to produce precursor levels of vitamin D, commonly found among individuals above the age of 40.

Supplement Daily with Vitamin D to Raise Circulating Blood Levels

The research team found that the level of circulating vitamin D in the blood affected the toll-like receptor (TLR) expression measured on white blood cell lymphocytes and monocytes. Specifically, they found that the TRL most affected by a vitamin D insufficiency is TLR7, which regulates the immune response against viruses. In many geographic regions, limited sun exposure during darker winter months is closely associated with vitamin D deficiency and increased risk for colds and influenza outbreaks.

The lead study author, Dr. John Wherry concluded “This study shows that sunlight, or more precisely the lack of vitamin D could have a role in the seasonally higher rates of infection… since vitamin D supplements are inexpensive and generally safe, this is a really exciting discovery.” It is best not to rely on sun exposure or dietary sources to obtain vitamin D. Most health-minded adults will want to supplement with an oil-based form of Vitamin D3 (experts recommend starting with 5000 IU per day), and test twice a year using the 25(OH)D blood test to confirm optimal levels above 50 ng/mL to achieve optimal protection against colds, flu and many viral infection strains.