The effects did not differ by sex or by age group .
Conclusions Evidence on the effects of supplementation of low concentrations of vitamin B12 and folate on haematological parameters in community-dwelling older people is inconclusive .
Background / objectives Low vitamin B12 and folate levels in community-dwelling older people are usually corrected with supplements .
However , the effect of this supplementation on haematological parameters in older persons is not known .
Effects of folic acid supplementation on psychomotor performance and hemorheology in healthy elderly subjects.
Cognitive impairment is associated with increased blood concentrations of homocysteine and high blood viscosity . Previous studies have shown that vitamin B supplementation reduces homocysteine and enhances cognitive function in patients with mild dementia and low serum folic acid . However , whether folic acid enhances cognitive function in elderly subjects without dementia and normal serum folic acid is unknown . Twenty-four healthy elderly subjects ( age 73.0+/-5.6 years , mean+/-S.D. ) with normal serum folic acid ( 6.3+/-2.4 microg/l ) and Mini Mental State Examination ( MMSE ) > 27/30 were r and omized to 4-week treatment with folic acid 5mg/day or placebo  in a r and omized , placebo-controlled , parallel-group study . Continuous Attention Test ( CAT ) , Four-Choice Reaction Time ( FCRT ) , Digit-Symbol Substitution ( DSS ) , Scanning Memory Sets ( SMS ) , and blood viscosity for different shear rates were measured before and after treatment . Folic acid supplementation induced a significant increase in serum folic acid levels ( + 13.8 versus + 1.6 microg/l , p<0.001 ) and fall in homocysteine levels ( -1.91 versus -0.41 micromol/l , p=0.05 ) compared to placebo . However , there was no significant change in CAT , FCRT , DSS , SMS , and blood viscosity between the two groups . Short-term folic acid supplementation does not enhance psychomotor performance or reduce blood viscosity in healthy elderly subjects with normal serum folic acid levels and preserved cognitive function
The effects did not differ by sex or by age group .
Conclusions Evidence on the effects of supplementation of low concentrations of vitamin B12 and folate on haematological parameters in community-dwelling older people is inconclusive .
Background / objectives Low vitamin B12 and folate levels in community-dwelling older people are usually corrected with supplements .
However , the effect of this supplementation on haematological parameters in older persons is not known .