Vitamin B-12 status did not change significantly after treatment in the placebo group with daily supplementation with high doses of oral vitamin B-12 alone or in combination with folic acid.

Oral vitamin B-12 supplementation corrected mild vitamin B-12 deficiency.

Vitamin B-12 + folic acid supplementation increased red blood cell folate concentrations and decreased total homocysteine concentrations by 36%.

Improvement in memory function was greater in the placebo group than in the group who received vitamin B-12 alone. Neither supplementation with vitamin B-12 alone nor that in combination with folic acid was accompanied by any improvement in other cognitive domains.