Iron Deficiency, Pernicious/B12, and Folate

What is the most common cause of anemia worldwide?

Iron deficiency anemia.

What type of anemia is iron deficiency anemia?

Microcytic, hypochromic anemia.

Why does iron deficiency produce microcytic hypochromic red blood cells?

Without iron, hemoglobin production decreases, producing smaller, paler RBCs.

What is the earliest laboratory indicator of iron deficiency?

Low ferritin.

What happens to serum iron in iron deficiency anemia?

It decreases.

What happens to TIBC in iron deficiency anemia?

It increases because the body makes more transferrin to capture iron.

What happens to the reticulocyte count in untreated iron deficiency anemia?

It is low because the bone marrow lacks iron to make RBCs.

List common causes of iron deficiency anemia.

Chronic blood loss, poor dietary intake, malabsorption, and increased physiologic demand.

What is the most common cause of iron deficiency anemia in adults?

Chronic blood loss.

What gastrointestinal conditions can cause chronic blood loss leading to iron deficiency anemia?

Peptic ulcers, colon cancer, GI bleeding, and chronic NSAID use.

Which patients should always be evaluated for gastrointestinal bleeding when newly diagnosed with iron deficiency anemia?

Adult males and postmenopausal women.

What diagnostic tests may be ordered to evaluate occult gastrointestinal bleeding?

Fecal occult blood testing, colonoscopy, and upper endoscopy.

Which patients are at highest risk for iron deficiency anemia?

Women of childbearing age, pregnant patients, infants, adolescents, vegans, vegetarians, bariatric surgery patients, and patients with malabsorption disorders.

What are the classic physical findings of iron deficiency anemia?

Koilonychia (spoon nails), glossitis, cheilitis, and pica.

What is pica?

A craving for nonfood substances such as ice, dirt, or clay caused by iron deficiency.

Which oral iron preparation is most commonly prescribed?

Ferrous sulfate.

What schedule is now recommended for oral ferrous sulfate?

Every other day because absorption is improved and GI side effects are reduced.

How should oral iron be taken for best absorption?

On an empty stomach with vitamin C if tolerated.

What decreases oral iron absorption?

Calcium, dairy products, antacids, coffee, and tea.

Why is vitamin C recommended with oral iron?

It increases iron absorption.

When is IV iron indicated?

When oral iron is ineffective, not tolerated, malabsorption exists, or ongoing blood loss continues.

When are packed red blood cells indicated for iron deficiency anemia?

Only for severe symptomatic anemia or significant blood loss.

How soon should the reticulocyte count increase after starting iron therapy?

Within 3–7 days.

How long does hemoglobin usually take to improve after starting iron therapy?

Approximately 2–4 weeks.

Why should iron therapy continue for several months after hemoglobin normalizes?

To replenish iron stores.

What common side effects occur with oral iron?

Constipation, GI upset, and black stools.

Why should patients taking oral iron increase fluid and fiber intake?

To reduce constipation.

How should liquid iron be administered?

Diluted, through a straw, followed by rinsing the mouth to prevent tooth staining.

Why should iron supplements be kept away from children?

Iron overdose is a leading cause of fatal poisoning in children.

What serious cardiovascular complications can occur if severe iron deficiency anemia remains untreated?

Angina, heart failure, and myocardial ischemia.

Which vitamin deficiency causes pernicious anemia?

Vitamin B12 deficiency.

What type of anemia is pernicious anemia?

Macrocytic (megaloblastic) anemia.

What is intrinsic factor?

A protein produced by gastric parietal cells that is required for vitamin B12 absorption.

Where is vitamin B12 absorbed?

The terminal ileum.

What is the most common cause of pernicious anemia?

Autoimmune destruction of gastric parietal cells causing loss of intrinsic factor.

Besides pernicious anemia, what other conditions can lead to vitamin B12 deficiency?

Gastric surgery, Crohn disease, terminal ileum disease or resection, chronic PPI use, chronic H2 blocker use, and strict vegan diets.

Why does vitamin B12 deficiency cause neurologic symptoms?

Vitamin B12 is required for normal myelin maintenance.

What are the classic neurologic manifestations of vitamin B12 deficiency?

Paresthesias, numbness, tingling, poor balance, ataxia, confusion, and memory impairment.

What oral findings are common in vitamin B12 deficiency?

Glossitis and a smooth, beefy-red tongue.

What laboratory findings are expected with vitamin B12 deficiency?

Elevated MCV, low vitamin B12 level, elevated methylmalonic acid, elevated homocysteine, hypersegmented neutrophils, and low reticulocyte count.

Which laboratory test is most specific for vitamin B12 deficiency?

Elevated methylmalonic acid.

How is pernicious anemia treated?

Lifelong vitamin B12 replacement, usually by intramuscular injection or intranasal administration.

Why are oral vitamin B12 supplements often ineffective in pernicious anemia?

The patient lacks intrinsic factor and cannot adequately absorb oral B12.

What nursing priority is especially important for patients with vitamin B12 deficiency?

Assess neurologic function and implement fall precautions.

Can neurologic damage from vitamin B12 deficiency become permanent?

Yes, if treatment is delayed.

What type of anemia is folate deficiency anemia?

Macrocytic (megaloblastic) anemia. f

What are common causes of folate deficiency?

Poor nutrition, alcoholism, pregnancy, malabsorption, methotrexate, anticonvulsants, trimethoprim, and hemodialysis.

What laboratory findings are expected in folate deficiency?

Elevated MCV, low folate level, and normal vitamin B12 level.

What is the major clinical difference between folate deficiency and vitamin B12 deficiency?

Folate deficiency does NOT cause neurologic deficits.

How is folate deficiency treated?

Oral folic acid replacement and increased dietary folate intake.

Which foods are rich in folate?

Leafy green vegetables, legumes, citrus fruits, and fortified grains.

Why should vitamin B12 deficiency always be ruled out before treating folate deficiency?

Folate therapy can correct the anemia while allowing irreversible neurologic damage from vitamin B12 deficiency to continue.

How can you quickly distinguish iron deficiency, vitamin B12 deficiency, and folate deficiency on an exam?

Iron deficiency is microcytic with low ferritin;

vitamin B12 deficiency is macrocytic with neurologic symptoms and elevated methylmalonic acid;

folate deficiency is macrocytic without neurologic symptoms.