Abstract
To date, vitamin D seems to have a significant role in affecting the prevention and immunomodulation in COVID-19 disease. Nevertheless, it is important to highlight that this pro-hormone has other several activities, such as affecting drug concentrations, since it regulates the expression of cytochrome P450 (CYP) genes. Efavirenz (EFV) pharmacokinetics is influenced by CYPs, but no data are available in the literature concerning the association among vitamin D levels, seasonality (which affects vitamin D concentrations) and EFV plasma levels. For this reason, the aim of this study was to evaluate the effect of 25-hydroxy vitamin D (25(OH)D3) levels on EFV plasma concentrations in different seasons. We quantified 25(OH)D3 by using chemiluminescence immunoassay, whereas EFV plasma concentrations were quantified with the HPLC–PDA method. A total of 316 patients were enrolled in Turin and Rome. Overall, 25(OH)D3levels resulted in being inversely correlated with EFV concentrations. Some patients with EFV levels higher than 4000 ng/mL showed a deficient 25(OH)D3 concentration in Turin and Rome cohorts and together. EFV concentrations were different in patients without vitamin D supplementation, whereas, for vitamin D-administered individuals, no difference in EFV exposure was present. Concerning seasonality, EFV concentrations were associated with 25(OH)D3 deficiency only in winter and in spring, whereas a significant influence was highlighted for 25(OH)D3 stratification for deficient, insufficient and sufficient values in winter, spring and summer. A strong and inverse association between 25(OH)D3and EFV plasma concentrations was suggested. These data suggest that vitamin D is able to affect drug exposure in different seasons; thus, the achievement of the clinical outcome could be improved by also considering this pro-hormone.
Highlights
Vitamin D is classified as a nutrient, and it is synthesized by the human body through the action of sunlight
Data recorded by the National Health and Nutrition Examination Survey (NHANES) show that
Several studies have shown that vitamin D is able to affect drug concentrations [22,23,24,25] and clinic features [26,27,28,29]
Summary
Vitamin D is recognized as a prohormone. Vitamin D is classified as a nutrient, and it is synthesized by the human body through the action of sunlight. These dual sources of vitamin D make it challenging to develop dietary reference intake values [1]. Vitamin D deficiency represents a public health problem in all age groups; studies are still lacking in most countries, on risk groups. Data recorded by the National Health and Nutrition Examination Survey (NHANES) show that
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