Vitamin D and Immunity

Over the last decade, many primary doctors have been checking vitamin D levels as part of wellness checks. Vitamin D is involved in over 300 bodily processes.  Roughly 40 % of Americans have low vitamin D levels, which may be impacting our health and immune function. This is especially noteworthy as COVID and the flu are widespread.Research shows that individuals with low vitamin D levels have a greater risk of infection while adequate vitamin D levels have been correlated with fewer colds, flu, viruses and infections. Vitamin D has been shown to help boost immune function and prevent inflammation due to the vitamin D receptors on our immune cells. When vitamin D is inadequate, these receptors do not get enough vitamin D to perform optimally. Additionally, some white blood cells need vitamin D to optimally attack pathogens. Lastly, vitamin D inhibits the ability of some viruses to replicate and grow.Vitamin D is an essential nutrient since the body cannot make it on its own. Dietary sources include liver, fish and egg yolks. Our bodies can make vitamin D with sunlight exposure, but this may be difficult depending on the time of year and length of sun exposure. Supplementation is often needed to boost vitamin D levels. It is important to note that the active form of vitamin D is D3, and that  most fortified foods contain vitamin D2, which is an inactive unabsorbable form of the vitamin.  The body can convert some vitamin D2 to D3, but choosing foods or supplements with vitamin D3 is much more effective.