Folate is part of a healthy diet and is commonly found in green leafy vegetables, legumes, nuts, orange juice and some fruits. Folate is a water-soluble form of vitamin B9 that the body requires for cell growth and reproduction. Essential for general health, folate has also been shown to reduce birth defects.

The body must digest and process folate before it can be used by the body. In fact, the body goes through several steps in order to “break down” the folate and get the full benefit. This is a complex process which is shown, step-by-step, in the chart below. As a result of these steps, the body makes a version of the folate called L-methylfolate.

L-methylfolate is used by the body in the nutritional management of neurotransmitters (necessary chemicals) that affect mood. The importance of L-methylfolate in depression is that it, unlike folic acid, can cross the blood brain barrier to help the L-methylfolate deficient brain create the neurotransmitters that affect mood. It has been shown that as many as 70% of people with depression have a genetic error called the MTHFR polymorphism that limits their body’s ability to reduce dietary folate or folic acid into L-methylfolate.

Other risk factors including certain medications, diseases, lifestyle habits, and age may also increase an individual’s risk of having a less than optimal amount of this necessary chemical, L-methylfolate, in the brain.