The Folic Acid Guide

Folic acid acts as a coenzyme in a variety of chemical reactions important to metabolism, including DNA metabolism and metabolism of a few mission critical amino acids.

With vitamin b12, folic acid is involved in methionine (an amino acid) creation from homocysteine. Too much homocysteine is implicated in increased risk for heart disease, and occurs when there is a deficiency of the b vitamins required to turn it into methionine.

Folates are essential for the production of red and white blood cells. In fact, with folate deficiency, there is a condition called macrocytic anemia. This is the production of abnormally large red blood cells. Symptoms can include tiredness, weakness, and shortness of breath, as the oxygen carrying ability of red blood cells is affected. Macrocytic anemia can result from either folate or vitamin b12 deficiency - the symptoms are the same, but to be treated, the cause needs to be known.

Another sign of folate deficiency is high blood levels of homocysteine.

Folates are found in food in leafy greens and liver. It is synthesized in the gastrointestinal tract. Alcoholism can hinder absorption of folate, and both pregnancy and cancer lead to extra requirements.

Whilst one is a healthy condition and the other not, they both involve greater cell activity - in the case of pregnancy, the formation of new life, and in the case of cancer, greater than normal cell division. Some medications also create a greater folate requirement.

When looking at recommended daily allowances, its important to understand the difference between folic acid and folates. Folic acid refers to the form of this vitamin found in supplements or fortified food, and folates refer to what is found in the body or in food.

The terminology differences arise from the fact that folic acid is more available to the body than folates. So 1 mcg folate is equivalent to 1 mcg Dietary Folate Equivalent (DFE); 1 mcg folic acid with meals or as fortified food equals 1.7 mcg DFE; and 1 mcg folic acid as a supplement on an empty stomach (which isn't recommended anyway!) equals 2 mcg DFE.

The rda for adults is 400 mcg DFE per day.

More information from the Linus Pauling Institute on folic acid