High levels of folate in the blood means that a person eats a diet which is rich in folic acid, takes vitamins, or take folic acid pills. Consuming more folate than the body needs does not cause any serious problems. However, according to a recent research, high folic acid supplementation is linked to a higher risk of COVID-19 infections and mortality.
The research published in the journal BMJ also found that having a prescription for the antifolate drug methotrexate has a negative impact of folic acid on COVID-19 if and when folic acid and methotrexate were given together.
The researchers at the UC Davis Health and the University of ALabama at Birmingham studied a large cohort of patients enrolled in the UK BioBank. UK BioBank is a big biomedical database which contains the health information.
"We examined whether or not COVID-19 diagnosis and death were linked to the large doses of folic acid - five times the safe upper limit - prescribed to patients for a variety of medically approved indications. We found that the risk of becoming infected and dying from COVID-19 disease and virus was significantly greater in the group who were previously treated with folic acid," said Ralph Green, Professor in the UC Davis Department of Pathology and Laboratory Medicine and co-senior author of the study.
Due to the makeup of the UK BioBank data, the current findings of the research are limited to people who are of 45 years of age and/or older who are also predominantly from White European ethnicities of the UK population.
"Our findings of the research could have several implications for patients who take supplementary folate for preventing the complications of any other pharmacological therapies. Despite taking folate in these cases is clearly indicated, clinicians and doctors should be cautious about excessive folate intake for thier patients. Of course, our results will require replication," said Angelo L. Gaffo, co-senior author and an associate professor of medicine in the Division of Rheumatology at the University of Alabama at Birmingham.
"The defined safe upper limit of folic acid is close to one milligram. Until we have more information, it would be prudent to avoid extremely high doses of folic acid unless it is medically indicated otherwise. In addition, high folic acid would be of greater concern in unvaccinated individuals," Green concluded.