Folic acid, folate, and 5-methyltetrahydrofolate are three forms of vitamin B9, which is essential for human health. Vitamin B9 is involved in DNA synthesis, cell division, and amino acid metabolism. It is especially important for pregnant women to consume adequate amounts of vitamin B9 to prevent neural tube defects in their offspring. However, there are differences between these three forms of vitamin B9 in terms of absorption, metabolism, and potential health benefits. This article will discuss the differences between folic acid, folate, and 5-methyltetrahydrofolate, and which form of vitamin B9 has better absorption property.
Also Read: Folate, Vitamin B6, and Vitamin B12 Intakes Could Reduce Hypertension, New Study Suggests
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Folic Acid
Folic acid is the synthetic form of vitamin B9 that is commonly used in fortified foods and dietary supplements. It is more stable than natural folate and has a longer shelf life. Folic acid is absorbed in the small intestine by a process that involves conversion to 5-methyltetrahydrofolate by the enzyme dihydrofolate reductase (DHFR). However, this conversion is incomplete in some individuals due to genetic variations in the DHFR gene, resulting in reduced bioavailability of folic acid. In addition, excessive intake of folic acid may mask vitamin B12 deficiency, leading to neurological damage.
Folate
Folate is the natural form of vitamin B9 found in food sources such as leafy green vegetables, beans, and liver. It is easily degraded by heat, light, and oxidation, making it less stable than folic acid. Folate is absorbed in the small intestine by a process that involves conversion to 5-methyltetrahydrofolate by the enzyme methylenetetrahydrofolate reductase (MTHFR). However, genetic variations in the MTHFR gene may also reduce the bioavailability of folate. Folate has been associated with a lower risk of chronic diseases such as cardiovascular disease, cancer, and cognitive decline.
5-methyltetrahydrofolate
5-methyltetrahydrofolate is the active form of folate that is directly involved in the one-carbon metabolism pathway. It is the form of vitamin B9 that is transported into cells and used for DNA synthesis and methylation reactions. 5-methyltetrahydrofolate is produced by the enzyme MTHFR and is readily available for cellular uptake. Unlike folic acid and folate, 5-methyltetrahydrofolate does not require conversion by enzymes and has been shown to have superior bioavailability. Studies have also suggested that 5-methyltetrahydrofolate may have benefits for cardiovascular health, cognitive function, and mood disorders.
Which Form of Vitamin B9 Has Better Absorption Property
The absorption of vitamin B9 is influenced by several factors, including the type of food source, the form of vitamin B9, and individual genetic variations. Folic acid must be converted to its active form, 5-methyltetrahydrofolate, by the liver before it can be absorbed by the body. This conversion process is not very efficient, and up to 40% of folic acid may not be converted to its active form.
Unlike folic acid, folate does not require conversion by the liver and is readily absorbed by the body. However, folate is less stable than folic acid and is often lost during food processing and storage. It is estimated that only about 50% of folate from food sources is absorbed by the body.
5-methyltetrahydrofolate does not require conversion by the liver, and studies have shown that it has superior bioavailability compared to folic acid and folate. One study found that supplementation with 5-methyltetrahydrofolate resulted in higher plasma folate levels compared to supplementation with folic acid. Another study found that supplementation with 5-methyltetrahydrofolate was equally effective at reducing plasma total homocysteine concentrations as folic acid supplementation (5).
Overall, 5-methyltetrahydrofolate appears to be the most effectively absorbed form of vitamin B9. It is readily available for cellular uptake and does not require conversion by the liver.
