Medicine & USMLE

Vitamin B9 (Folate)

  1. Vitamin B1 (Thiamine) Biochemistry
  2. Vitamin B1 (Thiamine) Deficiency
  3. Vitamin B2 (Riboflavin)
  4. Vitamin B3 (Niacin) Biochemistry
  5. Vitamin B3 (Niacin) Deficiency and Excess
  6. Hartnup Disease
  7. Vitamin B5 (Pantothenic Acid)
  8. Vitamin B6 (Pyridoxine)
  9. Vitamin B7 (Biotin)
  10. Vitamin B9 (Folate)
  11. Vitamin B12 (Cobalamin) Biochemistry
  12. Vitamins B9 and B12 Deficiencies
  13. Vitamin A (Retinol) Biochemistry
  14. Vitamin A (Retinol) Deficiency and Excess
  15. Vitamin C (Ascorbic Acid) Biochemistry
  16. Vitamin C (Ascorbic Acid) Deficiency and Excess
  17. Vitamin D Biochemistry
  18. Vitamin D Deficiency and Excess
  19. Vitamin E (Tocopherol/Tocotrienol)
  20. Vitamin K Biochemistry
  21. Vitamin K Deficiency
  22. Zinc
  23. Kwashiorkor and Marasmus


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
    • 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.