[Deficiency of folates in pregnancy: effect of supplementary folic acid]. A prophylactic supplementation of iron and folate in pregnancy. Low folate levels in the cognitive decline of elderly patients and the efficacy of folate as a treatment for improving memory deficits.
Higher folate needs are present during pregnancy, which may lead to tissular deficiency in the mother and to depleted newborn folate reserves. The aim of this work was to assess the prevalence of folate deficiency and to establish the rates of serum and red cell folate in two groups of mothers and newborn infants, one receiving only iron and the other iron and folate during pregnancy. The rates of serum and red cell folate found at the end of pregnancy were significantly higher in the group which received folate; however, the percentage of cases with tissular folate deficiency was low in both groups, with no significant difference (3.8% and 1.3%, respectively). These findings, along with the lack of effect of supplemental folate on erythropoiesis, pose some questions on the usefulness of supplemental folate during pregnancy in our country. 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. 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.
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.