An Op-Ed in MedPage Today highlights the evidence for the potential role of vitamin D in the fight against COVID. Low vitamin D levels are being linked to COVID fatality and ICU admission.
Some 40% of the US population is vitamin D deficient, while in Africa, some 20% are thought to be vitamin D deficient. With South Africa’s seasonal variations, vitamin D levels in adults and children may be adequate in summer and autumn but deficient in the winter, even given its ethnically diverse population.
The article reviews the evidence in favour of and against administering Vitamin D as an acute treatment. Causality can be inferred from correlational data by satisfying various criteria which includes consistency, specificity, temporality, and dose-responsiveness. This same approach was used to draw the link between lung cancer and smoking in 1964.
Studies have shown some striking associations between vitamin D sufficiency and COVID outcomes. In a study of 154 patients, patients with vitamin D deficiency (serum 25-OH-D <20 ng/mL) had a fatality rate of 21%, compared to a rate of 3% for those with higher levels. Firming up the case for causation, there is some randomised experimental data.
In a study of 76 COVID patients in Spain, 1 of 50 of patients who were given open-label calcifediol, a potent vitamin D analogue, were admitted to ICU whilst 13 of 26 who did not receive vitamin D were admitted to ICU.
Nursing homes in France often give vitamin D injections, and a quasi-experimental study showed that only 10% of nursing home residents receiving vitamin D progressed to severe COVID, compared to 31% who were not.
The authors conclude that doctors cannot always wait for perfect evidence as they have a duty of care, and given vitamin D’s safety profile, the evidence for its protective role should be acted upon.
Source: MedPage Today
