Folate and synthetic folic acid intake, serum B vitamin and homocysteine concentrations, and cognitive impairment in elderly Brazilians - Perucha, Viviane Ferri Ross; Aquino, Rita de Cássia de; Gaspareto, N; Guerra-Shinohara, Elvira Maria; Amorim, Patrícia Mendonça da Silva; Almeida, V. D (Journal of Aging Research & Clinical Practice, 2017)