Folates cognitive effect

Adverse effects include CNS symptoms (reversible blurring of vision, diplopia, dizziness and ataxia) and depression of cardiac AV conduction. Alimentary symptoms, skin rashes, blood disorders and liver and kidney dysfunction also occur. Osteomalacia by enhanced metabolism of vitamin D (enzyme induction) occurs over years so also does folate deficiency. Enzyme induction reduces the efficacy of combined and progestogen-only contraceptives. Carbamazepine impairs cognitive function less than phenytoin. 

Unfortunately, no true placebo-controlled, double-blind studies of the effects of folate deficiency on mental status have been performed. It is not known whether milder degrees of folate deficiency might produce subtle compromise of cognitive capacity. 

To ascertain whether dietary food records were inaccurate because of associated mild cognitive deficits, blood levels of these nutrients were measured. Scores on the Halstead-Reitan Category Test were worse in subjects with lower blood levels of ascorbate, riboflavin, Bj2, and folate, while those on the Wexler Memory Test were correlated with ascorbate and Bj2 levels. These findings do not appear to be explained by age variation within the group, since there was no overall correlation between any nutritional variable and age per se. To correct for any effects of educational status and income level, analysis of covariance was performed it did not alter the degree or the statistical significance of the associations between performance on the cognitive tests and blood levels of the vitamins. 

In the methionine cycle, cobalamin also plays a central role, as the methyl group of 5-methyltetrahydrofolate is first transferred to the cobalamin molecule and then further transferred to homocysteine to form methionine. This reaction explains the close connection of folate and cobalamin metabolism, as 5-methyltetrahydrofolate cannot be used for other reactions over than the methylation of homocysteine. Mild deficiency of folate and cobalamin is also associated with cognitive decline due to the neurotoxic effects of increased... 

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