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Folate/Folic acid ~more on B’s

Published February 8th, 2010 in Minerals & Vitamins

Folate/Folic acid ~more on B’s

Folates are found in a wide variety of foods. Richest sources are liver, dark green leafy vegetables, beans, wheat germ and yeast. Other sources are egg yolk, milk and dairy products, beets, orange juice and whole wheat bread.

Folate is a generic term for a water-soluble group of B vitamins including folic acid and naturally occurring folates. Folic acid is a synthetic folate compound used in vitamin supplements and fortified food because of its increased stability. The name comes from folium, which is the Latin word for leaves, because folates were first isolated from spinach in 1941. In 1962 Herbert consumed a folate-deficient diet for several months and recorded his development of deficiency symptoms. His findings set the criteria for the diagnosis of folate deficiency.

Folate coenzymes play an important role in the metabolism of several amino acids. The synthesis of the amino acid methionine from homocysteine requires a folate coenzyme and, vitamin B12. Tetrahydrofolic acid is involved in the synthesis of nucleic acids (DNA and RNA) – the molecules that carry genetic information in cells – and in the formation of blood cells. Folates are essential for normal cell division, proper growth and for optimal functioning of the bone marrow.

Sources

Folates are found in a wide variety of foods. Richest sources are liver, dark green leafy vegetables, beans, wheat germ and yeast. Other sources are egg yolk, milk and dairy products, beets, orange juice and whole wheat bread.

Most forms of folate in food are unstable. Fresh leafy vegetables stored at room temperature may lose up to 70% of their folate activity within three days. Considerable losses also occur through leaching into cooking water (up to 95%) and through heating.

Proper folate utilisation depends on an adequate supply of other B vitamin – B12 and B6 and vitamin C, which are involved in the chemical reactions needed for folate metabolism. Vitamin C may also provide the reducing conditions needed to preserve folates in the diet, and a diet deficient in folates is also likely to be deficient in vitamin C. Absorption occurs mainly in the upper part of the small intestine (jejunum).

Deficiency

Folate deficiency is one of the commonest vitamin deficiencies. It can result from inadequate intake, defective absorption, abnormal metabolism or increased requirements.

Diagnosis of a subclinical deficiency relies on demonstrating reduced red cell folate concentration or on other biochemical evidence such as increased homocysteine concentration. Early symptoms of folate deficiency are non-specific and may include tiredness, irritability and loss of appetite.

Severe folate deficiency leads to megaloblastic anaemia, a condition in which the bone marrow produces giant, immature red blood cells. At an advanced stage of anaemia symptoms of weakness, fatigue, shortness of breath, irritability, headache, and palpitations appear. If left untreated, megaloblastic anaemia may be fatal. Gastrointestinal symptoms also result from severe folate deficiency.

Deficiency during pregnancy may result in premature birth, infant low birth weight and foetal growth retardation. In children, growth may be retarded and puberty delayed.

Those at greatest risk

  • ulcerative colitis
  • food sensitivities
  • vegetarian
  • GERD
  • celiac disease
  • sprue
  • Crohn’s
  • weight-reducing diets
  • the elderly
  • economically underprivileged groups
  • atrophic gastritis
  • cancer
  • anemias
  • skin disorders
  • pregnancy and lactation
  • epilepsy
  • infection
  • renal failure /regular haemodialysis
  • intensive care /parenteral nutrition

History

1931 Wills in India observes the effect of liver and yeast extracts on tropical macrocytic anaemia and concludes that this disorder must be due to a dietary deficiency.
1941 Mitchell and colleagues suggest the name “folic acid”
1945 Folic acid cures megaloblastic anaemia during pregnancy.
1991 Folic acid supplementation reduces risk of neural tube defects by 70% among women who have  given birth to a child with birth defects.
1992 Butterworth finds that higher than normal serum levels of folic acid are associated with decreased risk of cervical cancer in women infected with human papillomavirus.
1993 The US Public Health Service recommends that all women of childbearing potential consume folate daily in order to reduce the risk of spina bifida and other neural tube defects.
1998 Fortification of all enriched cereal grains with folic acid becomes mandatory in the USA and in Canada.

You can’t go wrong with taking this vital B vitamin.  But don’t count on commercial foods to fill the need for you; they are a poor substitute for the real foods that are fresh, cost effective and locally available. High quality supplements are a must when it comes to the B family.  To your Good Health.

Tammera Karr has a private practice in Douglas County Oregon. You can read other articles written by Tammera in the reading room of her website or contact her at www.yourwholenutrition.com

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