Folate/folic acid
last authored: Nov 2009, David LaPierre
last reviewed:
Introduction
Folate, or vitamin B9, is an important precursor of DNA.
daily requirements
As folate is water soluble, it cannot be stored in the body and must be ingested.
Daily requirements are as follows:
- 0-6 months: 65 mcg
- 7-12 months: 80 mcg
- 1-3 years: 150 mcg
- 4-8 years: 200 mcg
- 9-13 years: 300 mcg
- 14 and older: 400 mcg
- pregnant women: 400-1000 mcg
- breastfeeding women: 500 mcg
- at risk pregancies: 4000 mcg
Expectant mothers should take folate supplementation 12 weeks before pregnancy and at least 12 weeks post-conception (ie after the neural tube has closed).
Sources
Folate can be found in the following foods:
- dark green leafy vegetables: spinach, turnip greens
- beans and legumes
- wheat bran
- dried yeast
- poultry, pork, shellfish; especially organ meats
- bright fruits and vegetables, especially citrus
- many foods, ie breads and cereals, are fortified with folate
Digestion, Absorption, and Metabolism
coming soon!
Biological Roles
Folate is important for DNA synthesis (one-carbon metabolism).
Action of dihydrofolate reductase (DHFR) produces tetrahydrofolate, which is used in the synthesis of thymine, a pyrimidine
Deficiency
Insufficient folate during early pregnancy can lead to neural tube defects, necessitating consistent intake of folate in all women who could conceivably conceive.
Increased risk factors include:
- multiple gestation
- drugs: phenytoin, methotrexate
- chronic hemolytic anemia
- malabsorptive conditions, ie celiac disease
- it can also lead to megaloblastic anemia due to diminshed synthesis of purines and pyrimidines and a lack of cell division
- diarrhea, lethargy, glossitis, stomatitis can also result
Stores can be depleted within a few days in periods of hemolysis.
Overdose
Too much folate may increase risk of cancers (ref).
Resources and References
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