A 46-year-old man with a history of heavy alcohol use presents with a peripheral smear showing hypersegmented neutrophils. Which vitamin deficiency is most likely?

A 46-year-old man with a history of heavy alcohol use presents with a peripheral smear showing hypersegmented neutrophils. Which vitamin deficiency is most likely?

• A. Folate (Vitamin B9)
• B. Vitamin B12
• C. Vitamin A
• D. Vitamin C

Answer: (A)

Hypersegmented neutrophils reflect impaired DNA synthesis in bone marrow precursors, a hallmark of megaloblastic anemia caused by deficiency of folate or vitamin B12. In someone with heavy alcohol use, folate deficiency is the most likely culprit because alcohol reduces folate absorption, increases its loss, and dietary intake is often poor. Folate is essential for making thymidine, a DNA building block; without it, developing blood cells can’t mature properly, leading to macrocytosis and hypersegmented neutrophils. While vitamin B12 deficiency can produce a similar smear, the alcohol-using context makes folate deficiency more probable and there are typically no neurologic signs yet. Vitamins A and C deficiencies don’t produce this hematologic pattern. Therefore, folate deficiency (vitamin B9) is the most likely cause.

Hypersegmented neutrophils reflect impaired DNA synthesis in bone marrow precursors, a hallmark of megaloblastic anemia caused by deficiency of folate or vitamin B12. In someone with heavy alcohol use, folate deficiency is the most likely culprit because alcohol reduces folate absorption, increases its loss, and dietary intake is often poor. Folate is essential for making thymidine, a DNA building block; without it, developing blood cells can’t mature properly, leading to macrocytosis and hypersegmented neutrophils. While vitamin B12 deficiency can produce a similar smear, the alcohol-using context makes folate deficiency more probable and there are typically no neurologic signs yet. Vitamins A and C deficiencies don’t produce this hematologic pattern. Therefore, folate deficiency (vitamin B9) is the most likely cause.