Folic acid

It is an adjuvant of the B-complex and is itself a complex of substances essential for the formation of red blood cells. It participates in carbon atom transfer reactions, e.g. synthesis of purine and thymidylated nucleotides, conversion of glycine to serine and methylation of homocysteine to methionine.

In animals, white blood cells are reduced by up to 80% if there is a folic acid deficiency. In children, its deficiency has been found to be associated with both congenital and acquired forms of heart disease. Its deficiency leads to megaloblastic anaemia similar to that caused by vitamin deficiency. B12.

Its RDA ranges from 50 to 100 microg in both children and adults. Body deposits are 5000 microg. Its normal serum levels must be above 6 ng/ml. Large doses may counteract the anticonvulsant effect of barbiturates.

Drug interactions: phenobarbital, phenytoin and primidone reduce serum levels, salicylazosulphapiridine, aminosalicylic acid, cycloserine, sulphonamides, nitrofurantoin, methotrexate, cholestyramine and oral contraceptives reduce absorption.

The most important natural sources are: green vegetables, raw fruit.

The main plant drugs containing this vitamin are: ivy, fenugreek, ginseng, bramble.