How should low ferritin and low omega‑3 fatty acid levels be treated?

Treatment of Low Ferritin and Low Omega-3

For low ferritin, start with oral iron supplementation (ferrous sulfate 325 mg daily or on alternate days) as first-line therapy, and address the underlying cause of iron deficiency; for low omega-3, the provided evidence does not contain specific treatment guidelines, so supplementation with EPA/DHA-containing fish oil supplements is reasonable based on general medical practice.

Low Ferritin Management

Diagnostic Confirmation and Thresholds

• Iron deficiency is confirmed when serum ferritin is <30-35 μg/L in adults without inflammatory conditions 1, 2.
• In the presence of inflammation or chronic disease, ferritin levels up to 50 μg/L may still indicate iron deficiency, and transferrin saturation <20% should be used as an additional diagnostic marker 1, 2.
• Even without anemia, symptomatic iron deficiency (fatigue, restless legs syndrome, pica, exercise intolerance) warrants treatment 3, 4, 2.

First-Line Treatment: Oral Iron

Oral iron is the preferred initial therapy for most patients with low ferritin 2, 5, 6.

• Dosing: Ferrous sulfate 325 mg daily or on alternate days (providing approximately 100-200 mg elemental iron daily in divided doses, or 3-6 mg/kg/day in children) 1, 4, 6.
• Alternate-day dosing may improve absorption and reduce gastrointestinal side effects 1.
• Co-administer with vitamin C to enhance absorption of non-heme iron, and avoid tea/coffee around meal times as they impair iron absorption 1.
• Common side effects include constipation, nausea, and diarrhea 1.

When to Use Intravenous Iron

Intravenous iron is indicated when 1, 2, 5:

• Oral iron is not tolerated due to gastrointestinal side effects
• Impaired iron absorption exists (celiac disease, atrophic gastritis, post-bariatric surgery)
• Chronic inflammatory conditions are present (chronic kidney disease, heart failure, inflammatory bowel disease, cancer)
• Ongoing blood loss continues
• Rapid iron repletion is needed (second/third trimester pregnancy, preoperative patient blood management)
• Repeated failure of oral therapy occurs

IV iron formulations and dosing 1:

• Calculate total iron deficit based on hemoglobin deficit and need to rebuild iron stores
• Administer doses every 3-7 days until total dose is completed
• Monitor ferritin levels and keep below 500 μg/L to avoid iron overload toxicity, especially in children and adolescents 1.
• Ferric carboxymaltose allows rapid administration of large single doses over 15 minutes 1.

Monitoring and Follow-Up

• Recheck hemoglobin, ferritin, and iron studies 8-10 weeks after initiating treatment 1, 4.
• Do not recheck ferritin immediately after IV iron as levels will be falsely elevated 1.
• For recurrent iron deficiency, consider proactive maintenance therapy when ferritin drops below 100 μg/L to prevent anemia recurrence 1.

Identify and Treat Underlying Causes

Common causes requiring investigation 1, 2, 5:

• Menstrual blood loss (most common in reproductive-age women)
• Gastrointestinal bleeding (requires endoscopic evaluation in many cases)
• Inadequate dietary intake (vegetarian/vegan diets, eating disorders)
• Malabsorption (celiac disease, atrophic gastritis, H. pylori infection)
• Pregnancy and lactation
• Chronic inflammatory conditions

Dietary Optimization

• Consume iron from highly bioavailable heme sources including red meat and seafood 1.
• Vegetarian diets have substantially lower iron bioavailability 1.
• Integrate dietary counseling emphasizing iron-rich foods 3, 4.

Important Caveats

• Do not supplement iron when ferritin is normal or elevated, as this is ineffective and potentially harmful 1, 4.
• In athletes, screen males annually and females twice yearly for iron deficiency 1.
• Parenteral iron is usually not indicated except in specific malabsorption conditions 1.

Low Omega-3 Management

The provided evidence does not contain specific guidelines for treating low omega-3 levels. Based on general medical knowledge, supplementation with EPA/DHA-containing fish oil supplements (typically 1-2 grams daily of combined EPA/DHA) is reasonable, along with dietary counseling to increase consumption of fatty fish (salmon, mackerel, sardines) 2-3 times weekly.