Fast Five Quiz: Vitamin B9 (Folate)

Emmanuel C. Besa, MD


November 07, 2022

Because folate is a water-soluble vitamin, toxicity is not a common concern. However, excessive consumption via supplements is possible. The primary issue associated with excessive folate supplementation is the potential masking of a vitamin B12 deficiency.

Ruling out a vitamin B12 deficiency in patients with a suspected folate deficiency is important because both conditions produce overlapping neurologic manifestations and cause megaloblastic anemia; however, folate treatment does not improve neurologic abnormalities due to vitamin B12 deficiency.

Mortality associated with folate toxicity is extremely rare. Combination therapy with levothyroxine and folate may be beneficial in hypothyroidism. Likewise, the use of various B vitamins, including folate, has been associated with lower risk for osteoporosis.

Learn more about vitamin B12-related neurologic diseases.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.