David Meltzer, Chief of Hospital Medicine at the University of Chicago, has explored the potential impact of diminished vitamin D levels on contracting the novel COVID-19 virus. In addition, this D deficiency tends to affect older adults, obese individuals and those living in nursing homes- many of the same demographics hit hardest by COVID-19 infections, and with the most vulnerable immune systems.ĭr. Vitamin D deficiencies abound worldwide, notably among individuals whose darker skin pigmentation makes absorbing the vitamin through sunlight all the more challenging. Before advising clients on supplementation, learn about the intricacies of this hormone-like vitamin and how it affects key aspects of the immune system. Perhaps best known for its ability to shore up bone health, vitamin D also plays an important role in immune function and inflammation.