Folate (vitamin B-9) is a naturally occurring nutrient important in the formation of red blood cells and growth of healthy cells. It is particularly important during pregnancy and helps prevent birth defects. 

A folate deficiency occurs when there are low levels of folate in the body. This may be down to a poor diet or an underlying medical condition, such as celiac disease. Foods rich in folic acid include leafy green vegetables, fruit, dried beans and nuts, and enriched foods such as cereals and grain products. 

Symptoms of a folate deficiency include anemia, mood changes, pale skin, poor digestion, poor immune function, weight loss, slow growth, fatigue, and weakness. 

Treatment of a folate deficiency involves dietary changes or supplements to increase the quantity of folate in the body. Medication may also be prescribed. Drug classes commonly prescribed to patients with a folate deficiency include folic acid and derivative supplements and iron combination supplements.