FOLIC ACID/FOLACIN (Vitamin B-9)

General - water-soluble; “smoker’s vitamin”;

• A conglomerate compound comprised of PABA (para-aminobenzoic acid), glutamic acid & the organic pigment pterin;
• First isolated from 4 tons of spinach leaf & named after Latin name for leaf: folium;
• Folic acid comes from dietary sources & is also made by healthy intestinal bacteria, that use dietary PABA as a precursor;
• History: yeast & liver extract cures macrocytic anaemia in 1931; name suggested in 1941; folate cures megaloblastic anaemia in 1945; requirement for humans estimated in 1962;

Nutrition

• Sources: best: liver, dark green leafy vegetables, dry beans & peas, wheat germ, yeast; good: egg yolk, broccoli, orange juice, peanuts, almonds, whole grains, Brussels sprouts; intestinal bacteria;
• Supplements: folate, B-complex, multi-vitamin & multi-mineral-vitamin formulations;
• Absorption: from small intestine; about 30 to 50% absorbed; circulates freely in blood;
• Improved by: presence of other vitamins & minerals;
• Antagonized by: alcohol; mal-absorption; the “pill” & other drugs; stomach disorders;
• Stability: destroyed by heat & oxygen; at room temperature, up to 70% of folate from vegetables is lost within 3 days; up to 95% may be lost in cooking water;
• Storage: mainly (6 months supply) in liver;
• Excretion: excreted through urine
• Metabolism: works with B-12; associated with glutamic acid, that is split off in intestinal wall before folacin is absorbed; healing, hyperthyroidism, haemolytic anaemia & pregnancy require increased amounts;
• Interactions: folic acid need increased by drugs, alcohol, oral contraceptives, antibiotics; sulpha drugs interfere with bacterial synthesis of folacin; aminopterin & streptomycin destroy folacin; high doses of folic acid may slow zinc metabolism;

Functions of Folic Acid

• Involved in all cells; indirectly affects all protein & enzyme metabolism;
• Necessary to convert phenylalanine into tyrosine & to oxidize & decarboxylate tyrosine;
• Required to form part of haemoglobin (porphyrin);
• Required for metabolism of long-chain fatty acids in brain;
• Involved in all biological reactions that involve transfer of methyl (CH3) groups: includes formation of methionine, serine, choline (from ethanolamine); synthesis of histidine; preparation of niacin for excretion; synthesis of all DNA & RNA bases;
• Especially important in the functions of rapidly dividing cells: red & white blood cells, tongue, intestinal wall, developing foetus;
• Co-enzyme in: forming red blood cells; synthesizing enzymes that control cell division; regulating embryonic development of nerve cells; amino acid metabolism; maintaining healthy cells in nervous system, sex organs, intestinal tract & blood;
• Essential for optimal functioning of nervous system & bone marrow;
• Involved in production of HCl;
• Essential for mental & emotional health; helps liver function (mobilizes fat from liver);
• Required to convert toxic homocysteine into the essential amino acid methionine;
• Pregnancy increases demand for folacin, for neural development of foetus;
• Synergies by: vitamin C & other B-complex vitamins;
• Antagonized by: alcohol, contraceptives, antibiotics, many drugs; stress & pregnancy;

Quantities

• Measurement: micrograms; milligrams;
• Optimum: (SONA) averages 300 to 1,000 μg/day;
• Individual optimum must be individually determined; especially important during pregnancy & foetal growth to prevent neural tube defects, cleft lip, cleft palate; supplementation during pregnancy recommended; requirement increases with rapid cell growth (pregnancy, hyperthyroid, haemolytic anaemia), size & metabolic rate;
• Minimum: (DRI) set at 400 μg/day (600 μg/day during pregnancy);
• Less than RDA: in excess of 10% of population, according to a U.S. government survey; clinical estimates suggest 70% of population may need more than they get;
• Deficiencies of folacin can result from: inadequate intake; impaired absorption due to low HCl (which requires folacin for its production), destroyed intestinal mucousa; increased requirement (leukemia, Hodgkin’s); increased losses;
• At risk: alcoholic; low socio-economic status: adolescents, pregnant adolescents, infants, prematures, young children & elderly; infants fed unfortified milk; women on the “pill”; people with stomach disorders; patients on drug treatments (cholestyramine, anti-epileptic drugs, sulphasalazine, anticancer drugs, phenobarb); people on haemodialysis or parenteral nutrition; poor, lonely people;
• Symptoms include: brain damage, learning disorders, retarded development of the newborn infant; effects on pregnant mother include: toxaemia of pregnancy, postpartum haemorrhaging, & iron-resistant (megaloblastic) anaemia;
• First symptoms of folic acid deficiency include poor memory from faulty nucleic acid synthesis, apathy, irritability, slowed intellectual processes; cracked lips & mouth corners, such as found in B-2 deficiency;
• Chronic deficiency results in anaemia’s — megaloblastic, pernicious & macrocytic;
• In the elderly poor cell growth, greying hair, impaired digestion;
• Toxicity: none associated with folacin; 100 times RDA is safe; 10 mg/day for 5 years without adverse effects; 15 mg/day produces no toxic effects;
• High folacin intake can mask vitamin B-12 deficiency (folic acid corrects anaemia symptoms but not neurological damage of B-12 deficiency;
• Reversed by: folate & B-12 administered together;

Therapy

• Supplemental levels of folic acid (400 to 1,000 μg/day) reverse deficiency symptoms & reduces incidence of neural tube defect in children of normal women & also women on anti-epileptic drugs;
• Beneficial in treating diarrhoea, sprue, dropsy, stomach problems, leg ulcers, glossitis;• Can improve circulation of people with atherosclerosis & diabetes;
• Folacin, + PABA, B-12 & B-5 may prevent greying of hair;
• 5 to 10 mg/day of folacin increased capillary blood flow, warms extremities, lowers atherogenic homocysteine levels; benefits atherosclerotics;
• 10 mg/day reduces abnormal cells in oral contraceptive users with cervical dysplasia;
• 10 mg/day folacin + 500 μg/day B-12 decreases abnormal cells in smokers with bronchial dysplasia;
• Oral intake of folic acid decreases chromosome breakages in human cells;