Associations of 25-hydroxyvitamin D with markers of inflammation, insulin resistance and obesity in black and white community-dwelling adults

• Lower 25-hydroxyvitamin D is associated with insulin resistance and inflammation.
• Lower 25-hydoxvitamin D is associated with obesity.
• Low 25-hydroxyvitamin D is associated with poor metabolic health irrespective of race.

AimsVitamin D is a fat-soluble vitamin classically known for its role in calcium absorption and bone health. Growing evidence indicates that vitamin D deficiency may be associated with inflammation, insulin resistance, and obesity. However, prior studies examining the association of vitamin D with metabolic risk factors had relatively low representation of individuals of black race, limiting their ability to characterize associations of vitamin D and parameters of metabolic health in black vs. white individuals.MethodsWe examined associations of 25-hydroxyvitamin D (25(OH)D) concentrations with markers of inflammation (interleukin [IL]-6, IL-10, high sensitivity C-reactive protein [hsCRP]), insulin sensitivity (adiponectin, resistin, HOMA-IR), and obesity (body mass index [BMI], waist circumference) in 1042 participants from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, a large national cohort of black and white adults 45 years or older.ResultsIn unadjusted analyses, lower 25(OH)D concentrations were associated with higher IL-6 and hsCRP concentrations; lower adiponectin concentrations; higher HOMA-IR; and higher BMI and waist circumference (P < 0.05 for all). After adjustment for sociodemographic, clinical, lifestyle, and laboratory variables, lower 25(OH) D concentrations remained associated with lower adiponectin concentrations, higher IL–6 concentrations, higher HOMA-IR, and higher BMI and waist circumference (P < 0.05 for all). The magnitude of these associations did not differ by race (Pinteraction > 0.1).ConclusionsLower 25(OH)D concentrations are associated with disturbances in metabolic health in both blacks and whites. Whether correcting vitamin D deficiency could offer a beneficial therapy for disease prevention requires further study.