Vitamin D is a fat-soluble nutrient that plays an essential role in immune function by affecting numerous cells that regulate the immune system response. It specifically enhances the fighting or defense response of certain types of white blood cells which results in decreased inflammation.
The T cells of the immune system or “killer cells” will not have the ability to attack serious infections or foreign pathogens in the body.
The deficiency of vitamin D has been linked to susceptibility to infection such as respiratory infections which has been seen in COVID 19 infection, like COVID19 pneumonia.
Vitamin D additionally helps promote calcium absorption and bone health. There is a recent suggestion from numerous studies that ensuring adequate vitamin D supplementation may help with decreasing the risk of respiratory infections.
There needs to be more research to see if vitamin D intake can be protective against COVID-19 since there is no current cure or therapy for the virus currently.
Vitamin D is usually produced as a byproduct and activated when the skin is exposed to sunlight (ultraviolet UVB light) and it can be found in foods such as sardines, fish liver oil, salmon, tuna, fortified milk or orange juice in a dietary supplement.
According to the Institute of Medicine, the safe upper limit of vitamin D is 4,000 IU per day for most adults.
The National Osteoporosis Foundation recommends 400-800 IU of vitamin D every day and adults over 50 get 800-1000 IU.
Some individuals with certain medical conditions need more. There are populations such as people with inflammatory bowel disease, Celiac Disease, malabsorption, obesity, kidney disease, and minorities who may need more supplementation with really low levels. Individuals with darker skin have a higher risk of vitamin D deficiency because melanin (pigment in the skin) decreases the skin’s ability to produce vitamin D with sun exposure.