Which age group is most likely to experience vitamin B12 deficiency due to decreased absorption and intake?

• A. Children under 5
• B. Young adults
• C. Older adults
• D. Athletes

Answer: (C)

As people age, the stomach tends to produce less acid and the cells that make intrinsic factor—the carrier needed to absorb B12 in the small intestine—often decline. This combination reduces the release of B12 from food and its subsequent absorption, so even with similar or adequate intake, older adults are more prone to not getting enough B12. Stores of B12 can last years, so deficiency develops slowly, and medications common in later life (like acid-reducing drugs) can worsen absorption. Because of these physiological changes and potential intake limitations, older adults are the group most likely to experience vitamin B12 deficiency due to decreased absorption and intake.