Folic acid is a member of the water-soluble B vitamin group. Isolated in 1946 from spinach leaves, its name comes from folium, the Latin word for leaf. In the body, folic acid is converted to its biologically active form tetrahydrofolic acid (THFA). Niacin and vitamin C are necessary for this conversion. Structurally, folic acid consists of a pteridine nucleus (containing two rings), conjugated with para-aminobenzoic acid, and glutamic acid. Hence, its chemical name is pteroylmonoglutamate.
Folic acid occurs in a wide variety of foods. Best sources include dark green leafy vegetables, brewer’s yeast, liver, and eggs. Other good sources are beets, broccoli, brussels sprouts, orange juice, cabbage, cauliflower, cantaloupe, kidney and lima beans, wheat germ, and whole grain cereals and breads. The body’s “friendly” intestinal bacteria also produce folic acid.
A recent study sought to examine the relationship between age-related hearing loss and vitamin B12 and folate levels in elderly adults. The study included 126 men and women over the age of 60 years who were tested for hearing loss. Researchers found that a low serum level of folate was significantly associated with hearing loss in high frequencies. Vitamin B12 was not significantly associated with hearing loss in this study. These results suggest that age-related hearing loss may be linked to poor micronutrient status and that further studies are warranted to determine the role of other vitamins and the risk of hearing loss.1
1 Lasisi AO, Gehintola FA, Yusuf OB. Age-related hearing loss, vitamin B12, and folate in the elderly. Otolaryngol Head Neck Surg. Dec2010;143(6):826-30.