Homocysteine, folate, vitamin B-12, and physical function in older adults: cross-sectional findings from the Singapore Longitudinal Ageing Study.

BACKGROUND: There is a paucity of studies, as well as inconsistent findings, on the associations of homocysteine, folate, and vitamin B-12 with physical function and decline in older persons.
OBJECTIVE: We investigated the independent associations of homocysteine, folate, and vitamin B-12 with gait and balance performance and Instrumental Activities of Daily Living (IADL) in community-living older persons.
DESIGN: We performed cross-sectional analyses on baseline data of 796 respondents in the Singapore Longitudinal Ageing Study who had laboratory measurements of fasting homocysteine folate and vitamin B-12 and completed Performance Oriented Mobility Assessment (POMA) of gait and balance and self-reports of IADLs.
RESULTS: In multivariate analyses in which sex, age, education, housing type, comorbidities, hospitalization, depression and global cognitive scores, BMI, creatinine, arthritis and hip fracture, serum albumin and hemoglobin, and physical activities were controlled for, we showed that homocysteine, independently of folate and vitamin B-12, showed significant negative associations with POMA balance (P = 0.02), POMA gait scores (P < 0.01), and IADL (P < 0.01). Serum folate showed a significant positive association only with POMA balance scores (P < 0.045). No significant independent associations for vitamin B-12 were observed.
CONCLUSIONS: The independent association of elevated homocysteine and low folate, but not vitamin B-12, on physical and functional decline was supported in this study. Interventional studies of the physical functional effects of folate and vitamin B-12 status in different populations are needed.