was higher and the intervention was longer (6.7 years) in
the SEARCH Collaborative Group study [34] versus 0.8mg
folic acid plus 0.4mg vitamin B(12) daily and 3.2 years in
the Ebbing study [33] matching placebo. Interventions in
the Ebbing study were also complicated, with oral treatment
with folic acid (0.8mg/d) plus vitamin B(12) (0.4mg/d) and
vitamin B(6) (40mg/d) (