http://ods.od.nih.gov/factsheets/folate.asp
Medical conditions that increase the need for folate or result in increased excretion of folate include:
pregnancy and lactation (breastfeeding)
alcohol abuse
malabsorption
kidney dialysis
liver disease
certain anemias
Medications that interfere with folate utilization include:
anti-convulsant medications (such as dilantin, phenytoin and primidone)
metformin (sometimes prescribed to control blood sugar in type 2 diabetes)
sulfasalazine (used to control inflammation associated with Crohn's disease and ulcerative colitis)
triamterene (a diuretic)
methotrexate (used for cancer and other diseases such as rheumatoid arthritis)
barbiturates (used as sedatives)
What are some common signs and symptoms of folate deficiency?Folate deficient women who become pregnant are at greater risk of giving birth to low birth weight, premature, and/or infants with neural tube defects.
In infants and children, folate deficiency can slow overall growth rate.
In adults, a particular type of anemia can result from long term folate deficiency.
Other signs of folate deficiency are often subtle.
Digestive disorders such as diarrhea, loss of appetite, and weight loss can occur, as can weakness, sore tongue, headaches, heart palpitations, irritability, forgetfulness, and behavioral disorders [1,20]. An elevated level of homocysteine in the blood, a risk factor for cardiovascular disease, also can result from folate deficiency.
Many of these subtle symptoms are general and can also result from a variety of medical conditions other than folate deficiency. It is important to have a physician evaluate these symptoms so that appropriate medical care can be given.
Every one needs folic acid-here's why! 
