ABSTRACT
The World Health Organization and others have cited a widespread deficiency in vitamin D.4,5 Epidemiologic evidence suggests low vitamin D levels may cause premature aging, autoimmune disease, cancer, and cardiovascular disease.2,3,6 In one study, the authors observed those with the lowest vitamin D levels died more often.7 Recent evidence shows lower vitamin D levels are associated with a worse outcome from COVID-19 infection.8 Evolution is based on the successful reproduction of the species. Aging skin does not convert sunlight to vitamin D as well as younger skin.9,10 The paradox of vitamin D is that despite its many health benefits, randomized, controlled trials have failed to show a beneficial effect of testing for vitamin D levels and supplementation in the general population.1,11-12 These have been single-variable studies and may fail to capture the benefit of vitamin D supplementation. The National Academy of Medicine recommends a daily intake of 600 IU for young adults and 800 IU for seniors.1 The Endocrine Society suggests supplementation of 1,500 IU to 2,000 IU of vitamin D3 daily, which could result in optimal vitamin D levels in the blood (i.e., 40 ng/mL to 60 ng/mL).13 This is what I recommend for adult patients, especially seniors.