What is the recommended treatment plan for a 14-year-old female patient with iron deficiency anemia and low vitamin D levels?

Treatment Plan for Your 14-Year-Old Daughter

What the Lab Results Show

Your daughter has iron deficiency anemia and low vitamin D levels. Her ferritin is 10 ng/mL (very low iron stores), iron saturation is only 9% (severely depleted), and hemoglobin is 12.4 g/dL (borderline low for her age). Her vitamin D level of 28 ng/mL is also insufficient. 1, 2

Immediate Treatment Plan

Iron Supplementation

Start ferrous sulfate 200 mg (containing 65 mg elemental iron) once daily in the morning. 2 This is the most effective and affordable treatment for iron deficiency anemia in adolescents.

• Give the iron pill on an empty stomach for best absorption, but if she gets stomach upset, taking it with food is acceptable 2
• Add vitamin C 500 mg (like orange juice or a vitamin C tablet) with each iron dose to significantly boost iron absorption—this is especially critical given her severely low iron saturation of 9% 2, 3
• Take the iron every other day rather than daily if stomach side effects occur, as this actually improves absorption and reduces side effects 3
• Never give iron multiple times per day—once daily is more effective and better tolerated 2

Vitamin D Supplementation

Give vitamin D supplementation at the same time as the iron—there is no need to separate them, and giving them together improves medication compliance. 4 The typical dose for correcting vitamin D insufficiency in adolescents is 1,000-2,000 IU daily, though your doctor will specify the exact dose.

What to Expect

• Her hemoglobin should rise by approximately 2 g/dL after 3-4 weeks of treatment 2
• Continue iron therapy for 3 months after her blood counts normalize to fully replenish her iron stores 2
• If she doesn't improve after 4 weeks, contact your doctor—this may indicate she's not absorbing the iron properly or has ongoing blood loss 2

Finding the Cause

The most important next step is determining why she's iron deficient. 2 In a 14-year-old girl, the most common causes are:

• Heavy menstrual periods (menorrhagia)—this accounts for iron deficiency in 5-10% of menstruating adolescent girls 2
• Inadequate dietary iron intake (not eating enough red meat, beans, or iron-fortified foods) 1
• Celiac disease (gluten intolerance causing poor iron absorption)—your doctor should test for this with blood work 1, 2

Your doctor should assess her menstrual blood loss and may recommend celiac disease screening. 2

Follow-Up Schedule

• Recheck blood work in 4 weeks to confirm hemoglobin is rising by 2 g/dL 2
• Monitor every 3 months for the first year, then again after another year 2
• If anemia doesn't resolve within 6 months despite treatment, further investigation is needed 2

When to Consider IV Iron

If your daughter cannot tolerate oral iron despite trying at least two different formulations (like ferrous sulfate and ferrous gluconate), or if she has a condition affecting iron absorption like active inflammatory bowel disease or celiac disease with ongoing gluten exposure, intravenous iron may be necessary. 1, 2 However, oral iron is always tried first.

Important Points to Remember

• Don't stop the iron when her blood counts normalize—she needs 3 more months to refill her iron stores 2
• The vitamin C supplement is crucial for maximizing iron absorption given her severely low iron levels 2
• Address the underlying cause while treating with iron—if heavy periods are the problem, this needs separate management 2
• Side effects like constipation, nausea, or dark stools are common but usually manageable by taking iron with food or switching to alternate-day dosing 3