Folate Deficiency


Folate Deficiency

Folate (also known as folic acid or vitamin B9) is an important vitamin which is involved in a number of key functions in your body. It is essential for making and repairing DNA, producing red blood cells and the functioning of nerve cells. Additionally, folate is important for a healthy pregnancy and can play a part in maintaining a healthy heart. If you are deficient in folate, you can feel tired, weak and lacking in appetite.  

What is the MTHFR gene?

The MTHFR gene encodes an enzyme called methylenetetrahydrofolate reductase. The MTHFR enzyme converts folate from your food into an active form, 5-methyl-tetrahydrofolate. Only after this conversion has taken place can folate be used in your body.

What is the effect of genetic variation at the MTHFR gene?

People with no SNP produce an enzyme that can efficiently convert folate into its active form. Up to 40% of people have an allele at the MTHFR gene, which produces an enzyme that is less effective in converting folate into its active form. People with alleles are proven to have lower folate levels than those with no SNP. Having two alleles lowers the amount of folate further.

How does the MTHFR gene affect your heart?

Homocysteine is a protein found in the blood. High levels of homocysteine are linked to heart disease, strokes and pregnancy complications.

Folate works together with vitamin B12 to control the levels of homocysteine in the blood and support a healthy heart. By acting as coenzymes, folate and vitamin B12 enable a methyl group to be added to homocysteine. Through this reaction, homocysteine is converted to methionine and optimum levels of homocysteine in your blood are maintained. When levels of folate are too low, this reaction cannot take place and homocysteine levels rise. If you have concerns about your homocysteine levels, we recommend that you take one of our blood tests or see your GP.

What are the impacts of eating folate-rich foods?

Research has found that eating folate-rich foods can significantly reduce the difference in folate and homocysteine levels between individuals, with or without a risk allele. This means that even if someone has a risk allele at the MTHFR gene they can still have normal folate and homocysteine levels, as long as they have a folate-rich diet.

Folate occurs naturally in many foods, such as green leafy vegetables, chickpeas and black beans. Folate is water soluble meaning it dissolves easily in water. It is therefore better to steam or microwave (instead of boiling) when cooking in order to ensure folate isn’t lost from foods during cooking.

Do folic acid supplements work?

In general, supplements are usually not as good or as reliable as food.

Folic acid (the synthetic oxidised form of folate) is used in vitamin supplements and in fortified foods, such as flour and breakfast cereals. Folic acid metabolism involves the same process as folate metabolism, except it has one additional step at the beginning. This initial step is extremely slow, even in individuals with normal MTHFR functioning. Because of this, the majority of folic acid remains un-metabolised and so cannot be used by the body.

Even when the first step is completed, individuals with two risk alleles are unable to complete the subsequent step of converting folate into its active form effectively. So, in the majority of cases, folate is better obtained from diet than from a supplement.

In some cases, folate supplements are important. It is recommended that women who are trying to become pregnant, or are in their first 12 weeks of pregnancy, should take a daily supplement of folate to ensure normal development of the baby. To avoid the problem discussed above, do ensure that the folate in the supplement is in the active form (5-methyl-tetrahydrofolate) rather than folic acid. This will mean absorption is more effective.

Does the likelihood of having an allele vary among ethnic groups?

Yes, the likelihood of having an allele does significantly differ among ethnic groups. Around 25% of Hispanics, 10% of Caucasians and Asians, and 1% of African Americans have two alleles.

Backed by Science

Our in-house scientists have sorted through thousands of studies and we only use genes that are backed by a significant body of peer-reviewed research. Check out Nell’s Science Standard for more information.