Vitamin D is a superstar nutrient for supporting the immune system and reducing the risk of a cold, flu and acute respiratory tract infection. Researchers are now linking low vitamin D status (less than 20 ng/mL or 18 pg/mL, respectively) to an increased risk of COVID-19 in a study published this week. Vitamin D levels were tested in nearly 500 patients before they were tested for COVID-19 and the relative risk for infections was 1.77 in Vitamin D-deficient patients. Deficiency in this “sunshine vitamin” affects nearly half of the US population, with increased rates in persons with reduced sun exposure, darker skin, living in higher latitudes in the winter, nursing home residents and health care workers. Vitamin D is found in oily fish such as salmon, mackerel, herring, and sardines, red meat and eggs, however exposure to natural sunlight is an important way to support the body’s synthesis of vitamin D from ultraviolet B rays.
We recommend targeting 40-60 ng/mL for optimal immune health, leaning on the higher side for those with existing immune complications.