Certified Neuroscience Registered Nurse (CNRN) Practice Exam

Which population is at higher risk for vitamin B12 deficiency?

1. Young children

2. Pregnant women

3. Vegetarians and vegans

4. Adults over 50 years old

The correct answer is: Vegetarians and vegans

Vegetarians and vegans are at a higher risk for vitamin B12 deficiency primarily because vitamin B12 is naturally found in significant amounts only in animal products. Since individuals following a vegetarian or vegan diet do not consume meat, dairy, or eggs—key sources of this vitamin—they may not obtain adequate amounts through their diet. This lack of dietary intake can lead to a deficiency, especially if they do not incorporate fortified foods or supplements. While young children, pregnant women, and adults over 50 years old can also experience vitamin B12 deficiency due to various factors (such as increased nutritional needs, absorption issues, or dietary choices), vegetarians and vegans are distinctly vulnerable due to the absence of animal-derived sources of B12. Thus, they must be particularly mindful of their nutritional intake to prevent deficiency.