What is the average age group vulnerable to B12 deficiency due to dietary restrictions?

The correct answer highlights that vegans are particularly vulnerable to vitamin B12 deficiency due to their dietary choices. Vitamin B12 is primarily found in animal products, including meat, fish, dairy, and eggs. Individuals following a vegan diet do not consume these sources, which can make it challenging to obtain adequate levels of B12 solely from plant-based food.

Without careful planning, those adhering to a vegan diet may not include fortified foods or supplements that can provide the necessary amounts of this essential nutrient. It's critical for vegans to be aware of their B12 intake and to consider strategies to ensure they meet their nutritional needs, such as through fortified foods or supplements.

While other groups such as children, middle-aged individuals, and senior adults can also experience B12 deficiency, their vulnerabilities are often related to factors such as absorption issues, dietary inadequacies, or increased nutritional needs rather than strict adherence to a plant-based diet. Hence, vegans represent a more clear-cut example within the context of this question.