Condition

Iron Deficiency Anemia

Iron deficiency anemia develops when the body runs short of iron and can no longer make enough hemoglobin, the protein that carries oxygen in red blood cells, which often leaves people tired and short of breath. The strongest finding is for lactoferrin, a milk protein, which raised hemoglobin across trials with nearly 3,000 people. Evidence for chlorella and spirulina is limited, coming from small studies such as one in pregnant women whose risk of anemia was lower.

Sources: PMID 20013055

Supplements studied: 6
Graded outcomes: 8
Trials: 7
People studied: 42,003

Evidence by supplement

Strong
Moderate
Limited
Very limited

6 supplements

Lactoferrin

Lactoferrin: outcomes studied for Iron Deficiency Anemia
Outcome	Effect	Size	People
Hemoglobin Increase Large Increase	Improves (the measure goes up)	Large effect	2,992 people
Serum Iron Levels Large Increase	Improves (the measure goes up)	Large effect	1,500 people
Pregnancy IDA Treatment Moderate Increase	Improves (the measure goes up)	Moderate effect	2,041 people

Chlorella

Chlorella: outcomes studied for Iron Deficiency Anemia
Grade	Outcome	Effect	Size	Studies	People
	Anemia Risk Small Improvement	Improves (the measure goes down)	Small effect	1 study	70 people
Studies that measured anemia risk Chlorella pyrenoidosa supplementation reduces the risk of anemia, proteinuria and edema in pregnant womenPlant Foods Hum Nutr · PMID 20013055
	Blood Pressure	Improves (the measure goes down)		3 studies	70 people
Studies that measured blood pressure Effect of Chlorella supplementation on cardiovascular risk factors: A meta-analysis of randomized controlled trialsClin Nutr · PMID 29037431 Anti-hypertensive effect of gamma-aminobutyric acid (GABA)-rich Chlorella on high-normal blood pressure and borderline hypertension in placebo-controlled double blind studyClin Exp Hypertens · PMID 19811362 Quantifying the Impact of Algae Supplement on Blood Pressure: Systematic Review and Meta-analysis of Randomized Controlled Trials.Curr Probl Cardiol · PMID 35870546
	Leg Edema	Changes; see studies			70 people
	Proteinuria	Improves (the measure goes up)			70 people

Iron

Alertness: improves
Aerobic Exercise Metrics
Hemoglobin: improves

Iron: outcomes studied for Iron Deficiency Anemia
Grade	Outcome	Effect	Size	Studies	People
	Alertness Small Improvement	Improves (the measure goes up)	Small effect		294 people
	Aerobic Exercise Metrics No effect		NoneNo effect	2 studies	373 people
Studies that measured aerobic exercise metrics Clinical evaluation of iron treatment efficiency among non-anemic but iron-deficient female blood donors: a randomized controlled trialBMC Med · PMID 22272750 Four weeks of IV iron supplementation reduces perceived fatigue and mood disturbance in distance runnersPLoS One · PMID 25247929
	Hemoglobin	Improves (the measure goes up)		7 studies	4,421 people
Studies that measured hemoglobin Role of iron in the reduction of anemia among women of reproductive age in low-middle income countries: insights from systematic review and meta-analysis.BMC Womens Health · PMID 37069552 Oral iron supplementation and anaemia in children according to schedule, duration, dose and cosupplementation: a systematic review and meta-analysis of 129 randomised trials.BMJ Glob Health · PMID 36849195 Efficacy of daily versus intermittent oral iron supplementation for prevention of anaemia among pregnant women: a systematic review and meta-analysis.EClinicalMedicine · PMID 39114275 and 4 more on the Iron page
	Depression Symptoms	Improves (the measure goes down)		1 study	219 people
Studies that measured depression symptoms Randomized, double-blind, placebo-controlled trial of iron supplementation in female soldiers during military training: effects on iron status, physical performance, and moodAm J Clin Nutr · PMID 19474138
	Stress Signs and Symptoms	Improves (the measure goes down)		1 study	294 people
Studies that measured stress signs and symptoms Evaluation of a single dose of ferric carboxymaltose in fatigued, iron-deficient women--PREFER a randomized, placebo-controlled studyPLoS One · PMID 24751822
	Anemia Risk	Improves (the measure goes down)			34,564 people
	Fatigue Symptoms	Improves (the measure goes down)			154 people
	Ferritin	Improves (the measure goes up)			3,648 people
	Iron Deficiency Anemia Risk	Changes; see studies			34,564 people
	Iron Deficiency Risk	Changes; see studies			34,564 people
	Memory	Improves (the measure goes up)			294 people

Spirulina

Anemia Risk: improves
White Blood Cell Count: improves
Red Blood Cell Count: improves

Spirulina: outcomes studied for Iron Deficiency Anemia
Grade	Outcome	Effect	Size	Studies	People
	Anemia Risk Small Improvement	Improves (the measure goes down)	Small effect		40 people
	White Blood Cell Count	Improves (the measure goes up)		1 study	40 people
Studies that measured white blood cell count The effects of Spirulina on anemia and immune function in senior citizensCell Mol Immunol · PMID 21278762
	Red Blood Cell Count	Improves (the measure goes up)			40 people

Magnesium

Hematocrit
Transferrin: improves
Hemoglobin: improves

Magnesium: outcomes studied for Iron Deficiency Anemia
Grade	Outcome	Effect	Size	Studies	People
	Hematocrit No effect		NoneNo effect		45 people
	Transferrin	Improves (the measure goes up)		1 study	45 people
Studies that measured transferrin Magnesium supplementation and iron status among female students: The intervention study.J Med Biochem · PMID 36042899
	Hemoglobin	Improves (the measure goes up)			45 people
	Total Iron Binding Capacity	Improves (the measure goes up)			45 people

Zinc

Iron Absorption: improves

Zinc: outcomes studied for Iron Deficiency Anemia
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Iron Absorption	Improves (the measure goes up)		4 studies	22 people
Studies that measured iron absorption New insights about iron bioavailability inhibition by zincNutrition · PMID 17350802 Elevated intakes of zinc in infant formulas don not interfere with iron absorption in premature infantsJ Pediatr Gastroenterol Nutr · PMID 9740203 Zinc inhibits nonheme iron bioavailability in humansBiol Trace Elem Res · PMID 17873388 and 1 more on the Zinc page

Key findings

Hemoglobin IncreaseLactoferrinImproves (the measure goes up)
Serum Iron LevelsLactoferrinImproves (the measure goes up)
Pregnancy IDA TreatmentLactoferrinImproves (the measure goes up)

The Iron Deficiency Anemia protocol

2 primary supplements · 3 supporting supplements

Iron (Ferrous Bisglycinate preferred)25–50 mg elemental iron daily or every other day
Vitamin C200–500 mg with iron dose

See the full protocol

Studies cited

21 studies from PubMed

Effect of increasing concentrations of zinc on the absorption of iron from iron-fortified milkBiol Trace Elem Res · PMID 22760642
Zinc inhibits nonheme iron bioavailability in humansBiol Trace Elem Res · PMID 17873388
Elevated intakes of zinc in infant formulas don not interfere with iron absorption in premature infantsJ Pediatr Gastroenterol Nutr · PMID 9740203
New insights about iron bioavailability inhibition by zincNutrition · PMID 17350802
The effects of Spirulina on anemia and immune function in senior citizensCell Mol Immunol · PMID 21278762
Magnesium supplementation and iron status among female students: The intervention study.J Med Biochem · PMID 36042899
The benefits and harms of oral iron supplementation in non-anaemic pregnant women: a systematic review and meta-analysis.Fam Pract · PMID 39834271
Intermittent iron supplementation for reducing anaemia and its associated impairments in adolescent and adult menstruating womenCochrane Database Syst Rev · PMID 30699468
Effects of iron supplementation versus dietary iron on the nutritional iron status: Systematic review with meta-analysis of randomized controlled trials.Crit Rev Food Sci Nutr · PMID 29611716
The effects of oral ferrous bisglycinate supplementation on hemoglobin and ferritin concentrations in adults and children: a systematic review and meta-analysis of randomized controlled trials.Nutr Rev · PMID 36728680
Four weeks of IV iron supplementation reduces perceived fatigue and mood disturbance in distance runnersPLoS One · PMID 25247929
Efficacy of daily versus intermittent oral iron supplementation for prevention of anaemia among pregnant women: a systematic review and meta-analysis.EClinicalMedicine · PMID 39114275
Oral iron supplementation and anaemia in children according to schedule, duration, dose and cosupplementation: a systematic review and meta-analysis of 129 randomised trials.BMJ Glob Health · PMID 36849195
Role of iron in the reduction of anemia among women of reproductive age in low-middle income countries: insights from systematic review and meta-analysis.BMC Womens Health · PMID 37069552
Evaluation of a single dose of ferric carboxymaltose in fatigued, iron-deficient women--PREFER a randomized, placebo-controlled studyPLoS One · PMID 24751822
Clinical evaluation of iron treatment efficiency among non-anemic but iron-deficient female blood donors: a randomized controlled trialBMC Med · PMID 22272750
Randomized, double-blind, placebo-controlled trial of iron supplementation in female soldiers during military training: effects on iron status, physical performance, and moodAm J Clin Nutr · PMID 19474138
Chlorella pyrenoidosa supplementation reduces the risk of anemia, proteinuria and edema in pregnant womenPlant Foods Hum Nutr · PMID 20013055
Quantifying the Impact of Algae Supplement on Blood Pressure: Systematic Review and Meta-analysis of Randomized Controlled Trials.Curr Probl Cardiol · PMID 35870546
Anti-hypertensive effect of gamma-aminobutyric acid (GABA)-rich Chlorella on high-normal blood pressure and borderline hypertension in placebo-controlled double blind studyClin Exp Hypertens · PMID 19811362
Effect of Chlorella supplementation on cardiovascular risk factors: A meta-analysis of randomized controlled trialsClin Nutr · PMID 29037431