Low folate levels in the cognitive decline of elderly patients and the efficacy of folate as a treatment for improving memory deficits. Short-term folate, vitamin B-12 or vitamin B-6 supplementation slightly affects memory performance but not mood in women of various ages. Enhancement of recovery from psychiatric illness by methylfolate. Folate administration reduces circulating homocysteine levels in NIDDM patients on long-term metformin treatment. Folic acid in folate-deficient patients with epilepsy. Enhancement of the antidepressant action of fluoxetine by folic acid: a randomised, placebo controlled trial. Weekly may be as efficacious as daily folic acid supplementation in improving folate status and lowering serum homocysteine concentrations in Guatemalan women. A prophylactic supplementation of iron and folate in pregnancy. Folic acid supplementation in dementia: a preliminary report.
The relevance of low folate levels as determinants of cognitive deficits and the usefulness of folate supplementation in the treatment of cognitive deficits was reviewed from the literature. Over 40 papers and book chapters published in English, French, German, Italian and Spanish were examined. This represents those papers published in the international literature in the last 10 years which were identified by various key words including folate, cognition and aging (or ageing). Among these papers, only 13 articles specifically addressed issues relevant to the criteria adopted for this review. The remaining papers were principally concerned with depression and or with other pathologies of the aged associated with folate deficiency. Although the specific role of low folate levels in the physiopathology of dementia is still under debate, a growing consensus is emerging in the literature where low folate as well as cobalamin levels in aged patients with cognitive deficits are being considered as a sign of functional problems in the absorption and utilization of vitamins, and not merely as a sign of bad eating habits. In studies where folate compounds were evaluated for treatment effects, the results of a majority of investigations indicated that folate treatment was effective in lessening cognitive deficits. Treatment efficacy, however, has not yet been sufficiently demonstrated by these results because there were no controlled studies and the methodology was heterogeneous for the evaluation of cognitive characteristics. An ad hoc double-blind, controlled versus placebo pilot study was undertaken to evaluate the efficacy of folic acid in 30 aged patients with abnormal cognitive decline and folate level below 3 ng/ml to better understand the value of this type of intervention. Our results from this preliminary study demonstrated that patients treated with folic acid for 60 days showed a significant improvement on both memory and attention efficiency when compared with a placebo group. The intensity of memory improvement was positively correlated with initial severity of folate deficiency. On the contrary, the severity of initial cognitive decline was unrelated to the degree of folate deficiency. Based on research demonstrating associations between folate, B-12 and B-6 vitamins and cognition and mood, we investigated the effects of short-term supplementation in 211 healthy younger, middle-aged and older women who took either 750 microg of folate, 15 microg of vitamin B-12, 75 mg of vitamin B-6 or a placebo daily for 35 d. In addition, we examined associations between dietary intake of these vitamins and cognition and mood. Usual dietary intake status was estimated using a retrospective, self-report, quantified food frequency questionnaire. Participants completed alternate forms of standardized tests of cognitive processing resources, memory, executive function, verbal ability and self-report mood measures before and after supplementation. Supplementation had a significant positive effect on some measures of memory performance only, and no effect on mood. Dietary intake status was associated with speed of processing, recall and recognition and verbal ability. 41 (33%) of 123 patients with acute psychiatric disorders (DSM III diagnosis of major depression or schizophrenia) had borderline or definite folate deficiency (red-cell folate below 200 micrograms/l) and took part in a double-blind, placebo-controlled trial of methylfolate, 15 mg daily, for 6 months in addition to standard psychotropic treatment. Among both depressed and schizophrenic patients methylfolate significantly improved clinical and social recovery. The differences in outcome scores between methylfolate and placebo groups became greater with time. These findings add to the evidence implicating disturbances of methylation in the nervous system in the biology of some forms of mental illness. Metformin treatment increases circulating homocysteine levels. We studied whether administration of folate reduces serum total homocysteine levels in patients on long-term metformin treatment.
                A prospective, randomized, double-blind, placebo-controlled study lasting for 12 weeks and taking place in a university hospital setting.
                Thirty patients treated with a metformin dose of at least 1000 mg day-1 for a minimum of 1 year were included. At baseline serum total homocysteine levels were within the reference range. One patient who withdrew and one who died were excluded from the statistical evaluation. Twenty-six of the remaining patients suffered from NIDDM, the other two from hyperlipidaemia.
                Patients were randomized into two groups at week 0. The folate group received 0.25 mg day-1 of folate in addition to 60 mg day-1 of Fe2+, while the placebo group received only 60 mg day-1 of Fe2+.
                Fasting homocysteine, cysteine, cysteinylglycine, vitamin B12 and folate were measured at week 0, 4 and 12. Changes from week 0 to week 4 and from week 0 to week 12 were calculated.
                Folate administration reduced serum levels of total homocysteine in the folate group as compared with the placebo group by 13.9% (P < 0.01) and 21.7% (P < 0.001) at week 4 and 12, respectively. In the folate group versus the placebo group serum levels of vitamin B12 increased by 9.9% (P = 0.010) and 9.6% (P = 0.043) while folate levels increased by 96.9 and 89.9% at week 4 and 12, respectively.
                The present study indicates that the homocysteine-increasing effect of metformin can be counteracted by folate administration. A double-blind trial using folic acid 15 mg. daily and identical placebo was carried out in 51 epileptic patients having a serum folate level below 3.6 ng./ml. Treatment was for a minimum of six months and in 41 patients was for more than one year. There were no significant changes in the frequency of seizures, behaviour, and personality, or in a number of cognitive functions. A consistent finding in major depression has been a low plasma and red cell folate which has also been linked to poor response to antidepressants. The present investigation was designed to investigate whether the co-administration of folic acid would enhance the antidepressant action of fluoxetine.
                127 patients were randomly assigned to receive either 500 microg folic acid or an identical looking placebo in addition to 20 mg fluoxetine daily. All patients met the DSM-III-R criteria for major depression and had a baseline Hamilton Rating Scale (17 item version) score for depression of 20 or more. Baseline and 10-week estimations of plasma folate and homocysteine were carried out.
                Patients receiving folate showed a significant increase in plasma folate. This was less in men than in women. Plasma homocysteine was significantly decreased in women by 20.6%, but there was no significant change in men. Overall there was a significantly greater improvement in the fluoxetine plus folic acid group. This was confined to women where the mean Hamilton Rating Scale score on completion was 6.8 (S.D. 4. 1) in the fluoxetine plus folate group, as compared to 11.7 (S.D. 6. 7) in the fluoxetine plus placebo group (P<0.001).A percentage of 93. 9 of women, who received the folic acid supplement, showed a good response (>50% reduction in score) as compared to 61.1% of women who received placebo supplement (P<0.005). Eight (12.9%) patients in the fluoxetine plus folic acid group reported symptoms possibly or probably related to medication, whereas in the fluoxetine plus placebo group 19 (29.7%) patients reported such symptoms (P<0.05).
                Folic acid is a simple method of greatly improving the antidepressant action of fluoxetine and probably other antidepressants. Folic acid should be given in doses sufficient to decrease plasma homocysteine. Men require a higher dose of folic acid to achieve this than women, but more work is required to ascertain the optimum dose of folic acid. Daily folic acid (FA) supplementation improves folate status, lowers circulating homocysteine (Hcy) concentrations, and reduces the risk of neural tube defects. Little is known about the efficacy of weekly FA supplementation. The objective of this study was to compare the efficacy of weekly and daily FA supplementations in improving folate and vitamin B-12 status and lowering Hcy concentrations in healthy reproductive-aged women. A randomized, double-blind supplementation trial was conducted in Guatemala. A total of 459 women were assigned randomly to 4 groups to receive weekly (5000 or 2800 microg) or daily (400 or 200 microg) FA for 12 wk. Daily and weekly iron, zinc, and vitamin B-12 were also provided. We determined serum and RBC folate by microbiological assays, but the latter was available only at baseline. Serum Hcy and vitamin B-12 were also measured. We used generalized linear regression models to assess the effects of treatment on biochemical indicators. Supplementation improved folate status similarly across all 4 groups. Overall, mean serum folate concentrations increased by 15.4 nmol/L (95% CI: 13.8, 16.9) and the geometric mean serum Hcy concentration decreased by 9.8% (95% CI: -12.3, -7.1). Daily supplementation improved serum vitamin B-12 by 20% (95% CI: 8, 33.2), whereas weekly supplementation had no effect. In conclusion, weekly FA (either high or low dose) plus vitamin B-12 may be as efficacious as daily supplementation in improving serum folate and lowering Hcy concentrations in healthy women of reproductive age. The supplementation of iron and folic acid were studied in 567 pregnant women with 18 and 26 weeks of gestation. Sixty mg and 180 mg of iron were given daily to pregnant women of group I and group II respectively while 180 mg of iron and 5 mg folic acid were given to group III. The Hb values increased significantly in group II and III after supplementation for 1 1/2 months, however if supplementation was extended for 3 months, highly significant increase in Hb levels were observed in all these groups. These findings indicated that in supplementation for a shorter period, i.e. 1 1/2 months at least 180 mg of iron was needed, and only 60 mg of iron was sufficient to increase Hb levels for a supplementation of 3 months. Vitamin B12 deficiency was not detected in pregnant women both before and after supplementation with iron and iron plus folate for 3 months. It was suggested therefore that perhaps it was not necessary to supplement vitamin B12 to Thai pregnant women. In this study 15% of pregnant women had low serum folate with normal red cell folate level, and a greater number of women with low serum folate concentrations were observed after supplementation with iron alone for 3 months. However, increased serum folate and red cell folate levels after supplementation with 5 mg folic acid indicated that some pregnant women needed folate supplementation in preventing folic acid deficiency during pregnancy. Recent work on high plasma homocysteine levels in patients at risk for developing Alzheimer's disease has led to the hypothesis that folic acid supplementation might reduce risk in such patients. The authors report on the effects of folic acid 10 mg/day versus placebo on 11 patients (only 7 completers) with dementia and low-normal folic acid levels. This is the first study evaluating folic acid or placebo in patients with dementia. Subjects had low-normal baseline folic acid levels. The magnitude of change between baseline and second testing was not statistically significant between the 2 groups. However, there was a trend for the folate group to perform worse on two specific cognitive measures, suggesting a possible trend toward worsening of some cognitive abilities after the folic acid. The folic acid in very high doses was well tolerated. Larger studies are necessary before empirically administering folic acid to patients already suffering from dementia.
The limited available evidence suggests folate may have a potential role as a supplement to other treatment for depression. It is currently unclear if this is the case both for people with normal folate levels, and for those with folate deficiency.