High risk groups for developing this type of anemia are infants under 2 years of age, teenage girls, pregnant women, and the elderly. The first three groups fall into the category of periods of increased iron requirements. The elderly are at risk as they often have problems absorbing iron due to a decrease in hydrochloric acid secretion from the stomach.

Vitamin B₁₂ deficiency may not become apparent until after years of inadequate intake or secretion of intrinsic factor. Normal bodily stores of this vitamin can last from three to six years, providing a leeway, as it were, before the situation becomes directly apparent. Pernicious anemia is more common in people of Scandinavian, English, or Irish descent. Vitamin B₁₂ deficiency in the elderly can mimic Alzheimer's disease.

Folic acid deficiency is the most common vitamin deficiency in the world. As opposed to B₁₂, the body does not have large stores of this vitamin. A deficiency can lead to fetal abnormalities such as fetal alcohol syndrome or spina bifida.