Folate Health Risks
Folate Health Risks
Folate is an essential nutrient that everybody needs throughout the life cycle. It is necessary for red blood cell production and maturation, normal cell growth and DNA synthesis, and for proper body functioning and metabolism and overall health. But at no time is it more critical to have a sufficient intake of folate or folic acid than during pregnancy.
Folate deficiency during pregnancy greatly increases the likelihood of so-called neural tube defects such as spina bifida (where the fetal spine doe does not close properly). Initially, the neural tube does not refer to a tube per se, but to a flat sheet of nerve tissue. However, during normal fetal development, the flat sheet closes, so it does take on a tubular shape. Neural tube defects occur when the neural tissue closure remains incomplete, which is far more likely to happen if the mother is not taking in enough folate.
According to the National Center for Health Statistics, approximately 1 out of 2,000 children are born yearly with a neural tube defect, and 20 out of every 100,000 newborns have spina bifida. Research studies show that maternal folate supplements during pregnancy can decrease the risk of neurological tube defects. However, there also appear to be genetic factors at work which predispose some fetuses to neural tube defects due to the impaired transfer of folate from the mother to the fetus. Until more is known about the impact of the interaction between folate intake and genetics, to be on the safe side, pregnant women and women who could become pregnant are advised to eat a varied diet including plenty of folates and to consume folic acid fortified foods and to take folic acid supplements in addition.
Since folate is an essential nutrient not only in the earliest stages of life but throughout every stage of life, a deficiency at any time during the life cycle can have a major impact on an individual’s health. The specific symptoms that might be attributable to folate deficiency (although, of course, they can have other causes) are described in more detail in the section on Folate Deficiency. Some of the symptoms that might be indicative even in the early stages of deficiency include fatigue, weakness, pallor, loss of appetite, and insomnia. Skin problems, gastrointestinal disturbances, and gum infections are common as well. There can also be mental symptoms like irritability, confusion, poor memory, and depression. However, prolonged or severe deficiency associated with the development, also, of a serious red blood cell disorder known as macrocytic megaloblastic anemia.
Prior to the onset of macrocytic megaloblastic anemia, if there is a folate deficiency, low plasma concentrations of folate will show up in about a month. Then, after 3-4 months, there will also be diminished concentrations of RBC folate. After 4-5 months of inadequate folate intake, rapidly dividing cells in the GI tract and blood become macrocytic and megaloblastic. The term macrocytic refers to the increased volume of these red blood cells while the term megaloblastic refers to the fact that the cells are immature with shortened life spans. As the number of megaloblastic cells in the blood steadily increases, and the number of healthy red blood cells decreases, the oxygen-carrying capacity of the blood is diminished.
Macrocytic megaloblastic anemia caused by a deficiency in folic acid should not be confused with iron deficiency anemia, and it cannot be corrected with iron supplements like iron deficiency. As it progresses, instead of the red blood cells being small as they are with an iron deficiency, they are large and irregularly shaped. Because these immature oversized red blood cells are unable to carry properly out their function of ensuring adequate supplies of oxygen to the tissues, any aspect of normal body functioning could be compromised. However, when the blood disorder occurs during pregnancy--most likely late pregnancy, because during the early months, folic acid stored in the liver can provide some degree of protection--the health of both the mother and the unborn baby are in jeopardy. Hemorrhaging is possible, or when the baby is born, deformities, brain damage, and delayed growth are very likely. Taking folic acid supplements during pregnancy can prevent these problems.
Unfortunately, the proper treatment of folate deficiency sometimes gets to be more complex. In other words, for an individual displaying the associated symptoms, taking folic acid supplements might not be the simple fix one hopes it will be. The reason is that folate works closely with other nutrients. Among them are other B complex vitamins like B2, B3, B6, and B12, along with protein and vitamin C, just to name few. So even when the intake of folate is increased, if there is still a deficiency in one or more other essential nutrients, impaired body functioning can exist. This is especially true with vitamin B12 since the similarity of symptoms makes it hard to tell without proper testing whether a suspected deficiency is in folate, vitamin B12, or both. See the section on Folate Deficiency for a more detailed discussion.
It is also possible for the folate concentrations in the blood to become too high and produce a state of toxicity, which likewise can be harmful to the body. There is no evidence that consuming more than the RDA of dietary folate is in any way damaging, but there are health risks associated with excessive folic acid taken as supplements. A folic acid intake of 15 mg (15x the Tolerable Upper Limit) or more has been shown to produce signs of insomnia, malaise, irritability, and gastrointestinal distress. Even lower amounts (.8 mg to 5 mg) have been associated with increased risk of cancer and cancer mortality.