Folate is an essential dietary component that belongs to the B vitamin group. Folate is found in most plant material, but certain grains and green leafy vegetables can be a good source. Folic acid has a similar structure to folate, but is a form of the vitamin that is synthesised in the laboratory. A folate deficiency can cause certain birth defects, and for this reason folic acid is often added to foods such as bread to reduce the risk of the foaetal development of neural tube defects. Because folic acid is a synthesised form of naturally occurring folate, there are claim that folic acid may be less bioavailable or even detrimental to the health. There are claims for example, that folic acid can interfere with folate absorption and metabolism and may lower blood levels of folate. The insinuation here is that by consuming the synthetic folic acid an individual may be detrimentally affecting their folate status and their health. However, such claims when investigated through use of the nutritional literature appear to be false.
Folic acid is a synthetic form of folate. When absorbed folic acid is metabolised in the liver to folate via the dihydrofolate reductase enzyme system. Supplements of folic acid and fortification of foods with folic acid have been shown to raise plasma levels of folate as would be expected. As plasma levels of folate rise, plasma levels of homocysteine fall. This relates to the requirement of tetrahydrofolate, the active form of folate, to participate in the homocysteine pathway. Tetrahydrofolate allows the conversion of homocysteine to other compounds, thus reducing its accumulation in cells. High levels of homocysteine are generally seen as detrimental as they can cause damage to blood vessels and high homocysteine levels may be a risk factor for cardiovascular disease. Green leafy vegetables are a good source of folate. Folic acid is added to food to fortify them and is found in many multivitamin and mineral formulas.
For example, in one study researcher investigated the effects of consumption of folic acid fortified foods on a group of individuals from the population as a whole. The subjects were from groups who consumed a natural diet before the period where folic acid fortification of foods occurred in the United States, or from the period after it was implemented. The results of the study showed that those subjects who consumed a diet fortified with folic acid had significant increases in blood levels of folate. This indicated that the folic acid was efficiently converted to folate within the liver and the subsequent folate was then available in the blood for metabolic purposes. That this folate was effective in metabolic regulation was further demonstrated by a reduction in the levels of homocysteine in the blood of the subjects. As low levels of folate can significantly increase plasma homocysteine levels, the fall in the levels of homocysteine were an indication that the blood folate was metabolically active.
Eat Well, Stay Healthy, Protect Yourself
RdB
