Objective: To follow folate status, hematological and cognitive changes during the first year of institutionalization among elderly subjects.
Design: Prospective study.
Setting: Long-stay unit of the Dijon University Geriatric Hospital.
Subjects: Twenty women and four men older than 65 years admitted consecutively.
Main outcome measures: Folate and vitamin B-6 dietary intake was evaluated by a five-day record on admission (day 1 or d 1), at day 45 (d 45), day 90 (d 90), day 135 (d 135), day 180 (d 180), day 360 (d 360). Circulating levels of folate, vitamin B-6, total homocysteine (tHcy), blood counts and cognitive performance were determined in parallel.
Results: From d 1 to d 360, mean folate and vitamin B-6 intakes remained below the French RDA and mean folate intakes decreased significantly (delta = 10.2%, p < 0.05). Mean plasma or erythrocyte folate decreased significantly (delta = 33.7%, p <0.05 and delta = -30.2%, p < 0.001, respectively) from d 1 to d 360; no significant change was observed for the other blood parameters. The incidence of folate deficiency increased (8% vs. 37% for plasma folate <6.8 nmol/L and 8% vs. 17% for erythrocyte folate <340 nmol/L) from d I to d 360. Mean plasma pyridoxal 5'-phosphate (PLP) remained <20 nmol/L during the one-year follow-up. There was no difference between genders for plasma tHcy. Although mean plasma tHcy was <14 micromol/L. plasma tHcy was >14 micromol/L in about one-third of the subjects. At each period, 50% or more subjects were anemic (Hct <35% in women and Hct <40% in men), but the anemia was normocytic (MCV <100 fL). Subjects had a moderate dementia at admission, and no change was observed during the study.
Conclusions: Subjects were already vitamin B-6 deficient at admission. Folate status was impaired during the study. Low vitamin intakes were the main cause of vitamin B-6 deficiency and folate status deterioration. Hematology and mental status capacity were not aggravated by folate status deterioration. Plasma tHcy didn't appear to be an earlier predictor of folate deficiency.