Iron Supplementation Guidelines

Recommended Daily Iron Intake

The European Society for Clinical Nutrition and Metabolism (ESPEN) recommends that standard enteral nutrition should provide 18-30 mg of elemental iron per day with 1500 kcal 1, 2, 3
Parenteral nutrition should provide at least 1 mg/day of elemental iron, according to ESPEN guidelines 1, 2
For treatment of iron deficiency, the American Journal of Kidney Diseases suggests oral iron is typically given as 200 mg of elemental iron per day, divided into 2-3 doses 4

Ferrous sulfate (325 mg tablet) contains 65 mg elemental iron, as reported by the American Journal of Kidney Diseases and Gut 5, 6
Ferrous gluconate (325 mg tablet) contains 35 mg elemental iron, according to the American Journal of Kidney Diseases and Gut 5, 6
Ferrous fumarate (325 mg tablet) contains 108 mg elemental iron, as reported by the American Journal of Kidney Diseases and Gut 5, 6
Polysaccharide-iron complex contains 150 mg elemental iron, according to the American Journal of Kidney Diseases 5
Ferric maltol (30 mg tablet) contains 30 mg elemental iron, as reported by Gut 6

Iron absorption is inversely related to iron stores and is increased during erythropoiesis, according to the American Journal of Kidney Diseases 4
Food consumed within 2 hours before or 1 hour after an iron supplement can reduce absorption by up to 50%, as reported by the American Journal of Kidney Diseases 4
Aluminum-based phosphate binders can reduce iron absorption, according to the American Journal of Kidney Diseases 4

Common side effects of oral iron include gastrointestinal symptoms such as nausea, vomiting, and abdominal discomfort, as reported by the American Journal of Kidney Diseases and Annals of Internal Medicine 4, 7
Patients with difficulty tolerating iron supplements may benefit from smaller, more frequent doses, starting with a lower dose and increasing slowly, or trying a different formulation, according to the American Journal of Kidney Diseases 4

Full investigation of iron status should be performed in cases of anemia and persistent major fatigue, as recommended by ESPEN guidelines 1, 8
Investigation should include plasma iron, transferrin, transferrin saturation, ferritin, CRP, hepcidin, and evaluation of red blood cell morphology, according to ESPEN guidelines 1, 3

For correction of iron deficiency, a single IV dose of whole-body iron replacement (1g) may be given using carbohydrate products when oral supplementation is insufficient, as recommended by ESPEN guidelines 8, 9
In anemic critically ill patients with iron deficiency confirmed by low hepcidin levels, 1g of iron should be delivered via IV, according to ESPEN guidelines 8, 9
For pregnant women, the usual dose is 60 to 120 mg of elemental iron per day, while prenatal vitamins often include a lower dose of 30 mg, as reported by Annals of Internal Medicine 7

To measure treatment success, basic blood tests should be repeated after 8-10 weeks, as recommended by ESPEN guidelines 8
After restoration of hemoglobin and iron stores, blood count should be monitored periodically (perhaps every 6 months initially) to detect recurrent iron deficiency anemia, according to Gut 6

The British Society of Gastroenterology recommends 50-100 mg elemental iron once daily for moderately severe anemia 10

Alternate day dosing leads to significantly increased fractional and total iron absorption compared to daily dosing 10

If intolerance occurs, reduce to alternate-day dosing rather than abandoning oral therapy 10
Consider alternative formulations like ferric maltol (30 mg twice daily) for patients intolerant to traditional iron salts with moderate anemia (Hb >95 g/L) 10

Parenteral iron should be considered when oral iron is contraindicated, ineffective, or not tolerated 10
A single IV dose of 1 gram iron can be given using recent carbohydrate products (ferric carboxymaltose or ferric derisomaltose) 11

Continue oral iron for approximately 3 months after hemoglobin normalization to replenish iron stores 10
Monitor blood counts every 6 months initially to detect recurrent iron deficiency 10