General folate deficiency symptoms:

• Diarrhea
• loss of appetite
• weight loss

Additional signs:

• sore tongue
• heart palpitations
• weakness
• headache
• irritability

The deficiency may cause:

• fatigue
• acne
• sore tongue

Recommended Daily Allowance of folic acid is 400 mg per day (for adult male, female, pregnant and lactating women).

National Academy of Sciences: intake of folic acid should not exceed 1000 mg / day.

Vitamin B9 exists in foods in folate and folic acid forms.

Food rich in folate:

• green leafy vegetable (like spinach)
• oranges
• lentils
• pinto beans
• broccoli
• liver
• brewer's yeast

Good sources of folic acid:

• asparagus
• beets
• broccoli
• avocados
• beans
• soybeans
• lentils
• oranges
• peas
• turkey
• cabbage
• savoy
• spinach

Risk of toxicity is low because folic acid is water soluble.

Regular intake of large doses of Vitamin B9 can cause:

• digestive upset
• energy loss
• insomnia

Also it can mask a Vitamin B12 deficiency.

Vitamin B9 is water-soluble vitamin exists in tow forms: folic acid and folate.

Folate is necessary for:

• cell division and replication
• protein metabolism
• DNA replication
• red blood cells construction
• anemia prevention

Folic acid was discovered by Lucy Wills in 1931. It was firstly extracted from spinach in 1941. It was synthesised in 1946.