There has been growing interest in the protective health benefits of multivitamin use (MVU). Relatively little research has investigated the factors associated with MVU among adults across a broad age range, particularly among lower-income, racially/ethnically diverse adults. In light of standing MVU recommendations and documented health benefits for certain groups, as well as ongoing studies evaluating the potential health benefits of multivitamins, vitamin D, and calcium, research among this understudied population is warranted. The aims of this paper were to assess the association between MVU and (1) sociodemographic, (2) preventive/health, and (3) patient/provider factors among a racially and ethnically diverse adult sample of over 1,500 low-income housing residents living in Boston, Massachusetts (USA). Bivariate and multivariable logistic regression models were the primary analytic strategy for investigating these associations. In multivariable analyses, sociodemographic factors (female gender, older age, and White or Other race/ethnicity) were significantly associated with regular MVU (p < or = .05). Preventive/health variables (health status, physical activity, and body mass index) and characteristics of patient/provider relationships (having a regular provider, last provider visit, decision-autonomy, and quality of relationship) were not significantly associated with MVU. While more evidence is needed to understand the benefits of MVU, future studies should address low use of MVU among lower-income, multi-ethnic populations, particularly in light of health disparities.