Researchers from the Department of Medicine and Center for Health and the Social Sciences, University of Chicago, reported in the September 3rd. 2020 online edition of JAMA (Journal of the American Medical Association) Network Open that, “in this single-center, retrospective, cohort study, likely deficient vitamin D status was associated with increased COVID-19 risk, a finding that suggests that randomized trials may be needed to determine whether vitamin D affects COVID-19 risk.”
Vitamin D deficiency affects roughly half of the US population – with higher deficiency rates in people of darker skin or reduced sun exposure, which included people residing at higher latitudes. According to the Illinois researchers, “vitamin D treatment has been found to decrease other viral respiratory infections, especially in persons with vitamin D deficiency.”
The study – the Association of Vitamin D Status and Other Clinical Characteristics with Covid-19 Test Results – included data taken from 4314 patients, who were tested from March 3 to April 10, 2020. Patients were considered vitamin D deficient, if their most recent serum D level within one year before their first Covid-19 tests, was less than 20 ng/mL (25-hydroxycholecalciferol) or their 1,25 vitamin D status was less than 18 pg/mL.
“Vitamin D3 dosing was defined, based on most recent daily dose recorded over the past year, excluding the 14 days before testing: none, 1 to 1000 IU or a multivitamin, 2000 IU, or greater than or equal to 3000 IU. Indicators for treatment with vitamin D2 and calcitriol were also included,” commented the study authors.
Based on assessments, the patient were assigned to 1 of 4 categories, which reflected their likelihood of being vitamin D deficient at the time of COVID-19 testing: “likely deficient (last level deficient and treatment not increased), likely sufficient (last level not deficient and treatment not decreased), and 2 groups with uncertain deficiency (last level deficient and treatment increased, and last level not deficient and treatment decreased).”
The researchers said, “our results raise the consideration of whether treatment for vitamin D deficiency is associated with reductions in the risk of COVID-19, since vitamin D deficiency may be increased by many factors that could be associated with COVID-19 risk, including age, obesity, diabetes, and chronic illness.”
That conclusion led to the comment that, “the low costs of vitamin D and its general safety, at least at doses of up to 4000 IU per day, support arguments for population-level supplementation, perhaps for targeting groups at high risk for vitamin D deficiency and/or COVID-19.”
Before you decide to supplement with vitamin D beyond what is found in a multi-vitamin/mineral formulation, it’s best to check with your personal physician, who can order a vitamin D lab test, to ascertain your status – yielding appropriate intake guidelines.
Interested in a podcast? Check out Maximum Wellness, Episode 69: A Low Vitamin D Status Is Associated with COVID-19 Complications