Vitamin B9 (Folate)

Summary

Vitamin B9 (Folate) is a water-soluble vitamin that plays a key role as a component of THF (tetrahydrofolate). THF serves a key role in methylation reactions, such as those required for DNA and RNA synthesis. Folate is present in leafy green vegetables, and it is absorbed in the jejunum of the small intestine.

Key Points

• Folate (Vitamin B9)
  • Converted to tetrahydrofolic acid (THF), a coenzyme for 1-carbon transfer/methylation reactions
    • key role in nucleotide synthesis, especially thymine (see Purine Synthesis and Pyrimidine Synthesis)
  • Found in leafy green vegetables (“folate from foliage”)
  • Absorbed in the jejunum

Find Folate Biochemistry and other Vitamins among Pixorize's visual mnemonics for the USMLE Step 1 and NBME shelf exams.