What form of vitamin B12 is used in supplements and fortified foods?

• A. Crystalline B12
• B. Protein-bound dietary B12
• C. B12 bound to intrinsic factor
• D. B12 from dairy sources

Answer: (A)

In supplements and fortified foods, vitamin B12 is used in a crystalline form, which is a purified, synthetic version (usually cyanocobalamin) that is highly stable, easy to produce in bulk, and mixes well with foods and tablets. This stability is why it’s favored for fortification and over-the-counter products—the B12 remains intact through processing, storage, and cooking, delivering a consistent dose.

Dietary B12 found in foods is bound to proteins and requires gastric factors to be released and then absorbed, a process that isn’t ideal for standard fortification. The form bound to intrinsic factor is the intestinal absorption complex, produced in the body, not something added as a fortified ingredient. B12 from dairy is simply one natural food source, not the purified form used for supplements. So crystalline B12 is chosen for supplements and fortified foods because it can be produced cheaply at high purity and remains stable through typical food processing and storage.