Certified Nutrition Specialist (CNS) Practice Exam

Pernicious anemia is specifically linked to a deficiency of vitamin B12. This condition arises when the body cannot absorb sufficient vitamin B12 from the gastrointestinal tract, often due to a lack of intrinsic factor, a protein necessary for the absorption of vitamin B12. As a result, the body is unable to produce adequate numbers of healthy red blood cells, leading to symptoms such as fatigue, weakness, and neurological issues.

The other conditions listed do not relate to vitamin B12 deficiency. Scurvy is caused by a deficiency of vitamin C, which is critical for collagen synthesis and preventing bleeding. Rickets is associated with a lack of vitamin D, calcium, or phosphate, leading to softening and weakening of bones in children. Beriberi is a result of insufficient thiamine (vitamin B1), affecting the nervous and cardiovascular systems. These associations clarify why pernicious anemia is the correct answer regarding vitamin B12 deficiency.