Background: Deficiency of folic acid, vitamin B(6) and/or vitamin B(12) can result in elevated total plasma homocysteine concentrations (tHcy), which are considered to be a risk factor for vascular disease. Studies have shown that supplementation of the three vitamins can lower tHcy even in subjects with tHcy in the normal range.
Aim of the study: The aim of this study was to evaluate the effect of a 6 month supplementation with vitamin B(6), B(12) and folate on the concentrations of total plasma homocysteine and serum methylmalonic acid (MMA) of elderly women.
Methods: The study was designed as a randomized placebo controlled double-blind trial, and 220 healthy women (aged 60-91 years) were involved. The vitamin and mineral capsule contained pyridoxine (3.4 mg), folic acid (400 microg) and cobalamin (9 microg) in addition to other micronutrients. Blood concentrations of folate, cobalamin, tHcy, MMA and the activity coefficient of erythrocyte alpha-aspartic aminotransferase (alpha-EAST) were measured at baseline and after 6 months of supplementation. Dietary intake was evaluated at the beginning and the end of the intervention by two 3-day diet records.
Results: Median concentrations of serum cobalamin, serum folate and erythrocyte folate increased significantly and tHcy and alpha-EAST activity (indicative of improved status of vitamin B(6)) coefficient decreased significantly in the supplemented group. Median MMA concentration of the supplemented group was significantly lower than that of the placebo group after the intervention. The vitamin supplementation had a greater decreasing effect on the tHcy concentration of volunteers with lower vitamin and higher tHcy initial concentrations. In a linear regression model, baseline tHcy, serum folate, age and alpha-EAST activity coefficient were significantly correlated with the change in tHcy. The change in MMA in the supplement group was significantly associated to the baseline MMA values.
Conclusions: Our results show that a 6 month supplementation including physiological dosages of B vitamins improves the status of these nutrients and reduces tHcy in presumed healthy elderly women.